The One Best Thing Everyone Could Do to Slow Climate Change

There’s a website called Quora where people can ask and answer questions of all sorts. Lots of people use it, so Curtis Faith suggested that we—that is, everyone here reading this blog—try answering some of the questions there. That sounded like a nice idea, so now there’s a ‘topic’ on Quora called Azimuth Project. The questions we tackle will be listed there, so people can easily find them.

To get the ball rolling, Curtis posted this question:

What is the one best thing everyone could do to slow down climate change?

If you’re like me, the first thing you’ll want to do is question the question. Are we really looking for the one best thing everyone could do? Everyone in the world, including the billion poorest people?

In that case, many answers that leap to mind are no good. We can’t say “take fewer airplane trips” because most of those people don’t take airplane trips to begin with. We can’t say “drive less” because most of those people don’t have cars. And so on. It’s no fair! We need an easier question!

Well… let’s not try to second-guess the question. It’s actually fun to take it seriously and try to answer it. It’ll force us to think about the world as a whole, instead of the sins of our rich neighbors.

Here are 50 tips for how to fight global warming from Global Warming Facts. Could any of these be the right answer? How many of these are things that everyone on this Earth can do?

  1. Replace a regular incandescent light bulb with a compact fluorescent light bulb (cfl)
    CFLs use 60% less energy than a regular bulb. This simple switch will save about 300 pounds of carbon dioxide a year.
    We recommend you purchase your CFL bulbs at 1000bulbs.com, they have great deals on both screw-in and plug-in light bulbs.

  2. Install a programmable thermostat
    Programmable thermostats will automatically lower the heat or air conditioning at night and raise them again in the morning. They can save you $100 a year on your energy bill.

  3. Move your thermostat down 2° in winter and up 2° in summer
    Almost half of the energy we use in our homes goes to heating and cooling. You could save about 2,000 pounds of carbon dioxide a year with this simple adjustment.

  4. Clean or replace filters on your furnace and air conditioner
    Cleaning a dirty air filter can save 350 pounds of carbon dioxide a year.

  5. Choose energy efficient appliances when making new purchases
    Look for the Energy Star label on new appliances to choose the most energy efficient products
    available.

  6. Do not leave appliances on standby
    Use the “on/off” function on the machine itself. A TV set that’s switched on for 3 hours a day (the average time Europeans spend watching TV) and in standby mode during the remaining 21 hours uses about 40% of its energy in standby mode.

  7. Wrap your water heater in an insulation blanket
    You’ll save 1,000 pounds of carbon dioxide a year with this simple action. You can save another 550 pounds per year by setting the thermostat no higher than 50°C.

  8. Move your fridge and freezer
    Placing them next to the cooker or boiler consumes much more energy than if they were standing on their own. For example, if you put them in a hot cellar room where the room temperature is 30-35ºC, energy use is almost double and causes an extra 160 kg of CO2 emissions for fridges per year and 320 kg for freezers.

  9. Defrost old fridges and freezers regularly
    Even better is to replace them with newer models, which all have automatic defrost cycles and are generally up to two times more energy-efficient than their predecessors.

  10. Don’t let heat escape from your house over a long period
    When airing your house, open the windows for only a few minutes. If you leave a small opening all day long, the energy needed to keep it warm inside during six cold months (10ºC or less outside temperature) would result in almost 1 ton of CO2 emissions.

  11. Replace your old single-glazed windows with double-glazing
    This requires a bit of upfront investment, but will halve the energy lost through windows and pay off in the long term. If you go for the best the market has to offer (wooden-framed double-glazed units with low-emission glass and filled with argon gas), you can even save more than 70% of the energy lost.

  12. Get a home energy audit
    Many utilities offer free home energy audits to find where your home is poorly insulated or energy inefficient. You can save up to 30% off your energy bill and 1,000 pounds of carbon dioxide a year. Energy Star can help you find an energy specialist.

  13. Cover your pots while cooking
    Doing so can save a lot of the energy needed for preparing the dish. Even better are pressure cookers and steamers: they can save around 70%!

  14. Use the washing machine or dishwasher only when they are full
    If you need to use it when it is half full, then use the half-load or economy setting. There is also no need to set the temperatures high. Nowadays detergents are so efficient that they get your clothes and dishes clean at low temperatures.

  15. Take a shower instead of a bath
    A shower takes up to four times less energy than a bath. To maximize the energy saving, avoid power showers and use low-flow showerheads, which are cheap and provide the same comfort.

  16. Use less hot water
    It takes a lot of energy to heat water. You can use less hot water by installing a low flow showerhead (350 pounds of carbon dioxide saved per year) and washing your clothes in cold or warm water (500 pounds saved per year) instead of hot.

  17. Use a clothesline instead of a dryer whenever possible
    You can save 700 pounds of carbon dioxide when you air dry your clothes for 6 months out of the year.

  18. Insulate and weatherize your home
    Properly insulating your walls and ceilings can save 25% of your home heating bill and 2,000 pounds of carbon dioxide a year. Caulking and weather-stripping can save another 1,700 pounds per year. Energy Efficient has more information on how to better insulate your home.

  19. Be sure you’re recycling at home
    You can save 2,400 pounds of carbon dioxide a year by recycling half of the waste your household generates.

  20. Recycle your organic waste
    Around 3% of the greenhouse gas emissions through the methane is released by decomposing bio-degradable waste. By recycling organic waste or composting it if you have a garden, you can help eliminate this problem! Just make sure that you compost it properly, so it decomposes with sufficient oxygen, otherwise your compost will cause methane emissions and smell foul.

  21. Buy intelligently
    One bottle of 1.5l requires less energy and produces less waste than three bottles of 0.5l. As well, buy recycled paper products: it takes less 70 to 90% less energy to make recycled paper and it prevents the loss of forests worldwide.

  22. Choose products that come with little packaging and buy refills when you can
    You will also cut down on waste production and energy use… another help against global warming.

  23. Reuse your shopping bag
    When shopping, it saves energy and waste to use a reusable bag instead of accepting a disposable one in each shop. Waste not only discharges CO2 and methane into the atmosphere, it can also pollute the air, groundwater and soil.

  24. Reduce waste
    Most products we buy cause greenhouse gas emissions in one or another way, e.g. during production and distribution. By taking your lunch in a reusable lunch box instead of a disposable one, you save the energy needed to produce new lunch boxes.

  25. Plant a tree
    A single tree will absorb one ton of carbon dioxide over its lifetime. Shade provided by trees can also reduce your air conditioning bill by 10 to 15%. The Arbor Day Foundation has information on planting and provides trees you can plant with membership.

  26. Switch to green power
    In many areas, you can switch to energy generated by clean, renewable sources such as wind and solar. In some of these, you can even get refunds by government if you choose to switch to a clean energy producer, and you can also earn money by selling the energy you produce and don’t use for yourself.

  27. Buy locally grown and produced foods
    The average meal in the United States travels 1,200 miles from the farm to your plate. Buying locally will save fuel and keep money in your community.

  28. Buy fresh foods instead of frozen
    Frozen food uses 10 times more energy to produce.

  29. Seek out and support local farmers markets
    They reduce the amount of energy required to grow and transport the food to you by one fifth. Seek farmer’s markets in your area, and go for them.

  30. Buy organic foods as much as possible
    Organic soils capture and store carbon dioxide at much higher levels than soils from conventional farms. If we grew all of our corn and soybeans organically, we’d remove 580 billion pounds of carbon dioxide from the atmosphere!

  31. Eat less meat
    Methane is the second most significant greenhouse gas and cows are one of the greatest methane emitters. Their grassy diet and multiple stomachs cause them to produce methane, which they exhale with every breath.

  32. Reduce the number of miles you drive by walking, biking, carpooling or taking mass transit wherever possible
    Avoiding just 10 miles of driving every week would eliminate about 500 pounds of carbon dioxide emissions a year! Look for transit options in your area.

  33. Start a carpool with your coworkers or classmates
    Sharing a ride with someone just 2 days a week will reduce your carbon dioxide emissions by 1,590 pounds a year. eRideShare.com runs a free service connecting North American commuters and travelers.

  34. Don’t leave an empty roof rack on your car
    This can increase fuel consumption and CO2 emissions by up to 10% due to wind resistance and the extra weight – removing it is a better idea.

  35. Keep your car tuned up
    Regular maintenance helps improve fuel efficiency and reduces emissions. When just 1% of car owners properly maintain their cars, nearly a billion pounds of carbon dioxide are kept out of the atmosphere.

  36. Drive carefully and do not waste fuel
    You can reduce CO2 emissions by readjusting your driving style. Choose proper gears, do not abuse the gas pedal, use the engine brake instead of the pedal brake when possible and turn off your engine when your vehicle is motionless for more than one minute. By readjusting your driving style you can save money on both fuel and car maintenance.

  37. Check your tires weekly to make sure they’re properly inflated
    Proper tire inflation can improve gas mileage by more than 3%. Since every gallon of gasoline saved keeps 20 pounds of carbon dioxide out of the atmosphere, every increase in fuel efficiency makes a difference!

  38. When it is time for a new car, choose a more fuel efficient vehicle
    You can save 3,000 pounds of carbon dioxide every year if your new car gets only 3 miles per gallon more than your current one. You can get up to 60 miles per gallon with a hybrid! You can find information on fuel efficiency on FuelEconomy and on GreenCars websites.

  39. Try car sharing
    Need a car but don’t want to buy one? Community car sharing organizations provide access to a car and your membership fee covers gas, maintenance and insurance. Many companies – such as Flexcar – offer low emission or hybrid cars too! Also, see ZipCar.

  40. Try telecommuting from home
    Telecommuting can help you drastically reduce the number of miles you drive every week. For more information, check out the Telework Coalition.

  41. Fly less
    Air travel produces large amounts of emissions so reducing how much you fly by even one or two trips a year can reduce your emissions significantly. You can also offset your air travel carbon emissions by investing in renewable energy projects.

  42. Encourage your school or business to reduce emissions
    You can extend your positive influence on global warming well beyond your home by actively encouraging other to take action.

  43. Join the virtual march
    The Stop Global Warming Virtual March is a non-political effort to bring people concerned about global warming together in one place. Add your voice to the hundreds of
    thousands of other people urging action on this issue.

  44. Encourage the switch to renewable energy
    Successfully combating global warming requires a national transition to renewable energy sources such as solar, wind and biomass. These technologies are ready to be deployed more widely but there are regulatory barriers impeding them. U.S. citizens, take action to break down those barriers with Vote Solar.

  45. Protect and conserve forest worldwide
    Forests play a critical role in global warming: they store carbon. When forests are burned or cut down, their stored carbon is release into the atmosphere – deforestation now accounts for about 20% of carbon dioxide emissions each year. Conservation International has more information on saving forests from global warming.

  46. Consider the impact of your investments
    If you invest your money, you should consider the impact that your investments and savings will have on global warming. Check out SocialInvest and Ceres to can learn more about how to ensure your money is being invested in companies, products and projects that address issues related to climate change.

  47. Make your city cool
    Cities and states around the country have taken action to stop global warming by passing innovative transportation and energy saving legislation. If you’re in the U.S., join the cool cities list.

  48. Tell Congress to act
    The McCain Lieberman Climate Stewardship and Innovation Act would set a firm limit on carbon dioxide emissions and then use free market incentives to lower costs, promote efficiency and spur innovation. Tell your representative to support it.

  49. Make sure your voice is heard!
    Americans must have a stronger commitment from their government in order to stop global warming and implement solutions and such a commitment won’t come without a dramatic increase in citizen lobbying for new laws with teeth. Get the facts about U.S. politicians and candidates at Project Vote Smart and The League of Conservation Voters. Make sure your voice is heard by voting!

  50. Share this list!
    Spread this list worldwide and help people doing their part: the more people you will manage to enlighten, the greater YOUR help to save the planet will be (but please take action on first person too)! If you like, you are free to republish, adapt or translate the list and post it in your blog, website or forum as long as you give us credit with a link to the original source.

There are a lot of great ideas here, but if we look for those that everyone can do, there aren’t many.

What’s the most important item that was left off this list?

I’ll give my answer to Curtis’ question after I’ve heard some of yours. It’s a tough question but I have an idea. And no, it’s not “join the Azimuth Project”.

142 Responses to The One Best Thing Everyone Could Do to Slow Climate Change

  1. Arrow says:

    The question asks about “the one best thing” not 50 things.

    My answer is “don’t produce offspring”.

    • John Baez says:

      Arrow wrote:

      The question asks about “the one best thing” not 50 things.

      Right. The list of 50 was just to give readers here some ideas, in case they’re feeling stuck… but also to show how few of these ideas are really things that everyone can do.

      Your idea, on the other hand, is someone everyone can do. I like it!

    • Frederik De Roo says:

      That’s something everyone can do but not what everyone should do.

      I’d prefer to rephrase it to “have not more than two children.”

      More sarcastically, if the question would really be the “one best thing”, committing suicide (after shutting down a power plant in case you’re operating on one) would be even more effective than not producing offspring.

      • Florifulgurator says:

        “have not more than two children”

        — I’ve heard that excuse often enough. It would still contribute to population growth – execpt the parents commit suicide asap… :-)

        We need to reduce population to one below the planet’s biophysical carrying capacity (which is currently estimated as 1-3 billion). However, the carrying capacity is meanwhile beginning to shrink (Watch this year’s agricultural failures due to droughts and/or floods. Cf. also: Net plant productivity decline, ocean phytoplankton decline).

        Lovelock estimates a carrying capacity of 0.5 billion by the year 2100. A trivial corollary to that conjecture is: Procreation contributes to genosuicide.

        —————

        The One Best Thing I suggest for those poor for whom lightbulbs, cars, fridges etc. are irrelevant – but who still enjoy the luxury of open fire: Live carbon negative. Just pour a bucket of water on your fireplace and mix the resulting activated biochar into manure/compost. Voila, carbon sequestrated as terra preta.

        • Frederik De Roo says:

          We need to reduce population to one below the planet’s biophysical carrying capacity

          I agree with that, but if having no children out of environmental awareness happens purely by free choice, only the most environmentally minded will stop reproducing. So I conjecture that the remainder of humanity will care even less about the environment, since the next generation of children will grow up in less environmentally minded families. So one would have to find some solution for this problem, I think.

        • John Baez says:

          Frederik wrote:

          … if having no children out of environmental awareness happens purely by free choice, only the most environmentally minded will stop reproducing. So I conjecture that the remainder of humanity will care even less about the environment, since the next generation of children will grow up in less environmentally minded families. So one would have to find some solution for this problem, I think.

          Good point. How about: “don’t have offspring; if you want children, adopt them and raise them to see the importance of preserving the Earth and the wisdom of valuing the transmission of memes over the transmission of genes.”

        • Frederik De Roo says:

          John said:

          How about: “don’t have offspring; if you want children, adopt them and raise them to see the importance of preserving the Earth and the wisdom of valuing the transmission of memes over the transmission of genes.”

          Ah, that’s a very nice formulation. But I guess that the ability to see “the importance of [...] and valuing [...]” is partly genetically coded, so I’m not sure this guideline would really keep working in the very long term. So, as soon as the carrying capacity is reached, one should reformulate it.

        • Florifulgurator says:

          The following logical conlusions might outrage a few:

          Plan A: Right now it might suffice to have a voluntary sterilization program with some monetary incentive. But time is short.

          Plan B: It seems soon the only sapient solution would be mandatory mass sterilization with a lottery to pick out a few fertile humans for the bottleneck population.

        • Eric says:

          If these are the types of solutions you guys take seriously, then no wonder no one pays attention. It makes me wonder why I am paying attention.

        • Frederik De Roo says:

          With respect to Eric’s and Flori’s comments:

          As the Indian family planning of the late ’70’s caused

          A strong backlash against any initiative associated with family planning followed the highly controversial program, which continues into the 21st century

          I don’t think mass sterilization would be an effective option. Even those who are not opposed against the idea should consider the fact that perhaps it’s impossible to be carried out against the human will.

          However, I do think that, eventually, carrying capacity will be reached anyway, whether planned or unplanned. (i.e. I think it will be reached unplanned)

          And, somewhat diverging, while considering a downscaling of the genetic information from a purely theoretical (!) point of view, a lottery seems to be the only honest way to deal with that, or not? To me seems a bit like “the library is on fire, you can rescue 10% of the books, but you haven’t read any, which books do you pick out?” Or do we know the genome better than that?

        • OK, this thread derailed some time ago, and even got scolded some; but just for fun — maybe this is urban legend, but it sounds right — “reportedly” India discovered as a side-effect of their family prevention — sorry, “planning” — program that couples with a TV in the bedroom had fewer children; and this correlation was stronger than any distribution of contraceptive tools or substances. So, clearly, the best way to curb population growth is to make sure everyone has a TV in their bedroom. Right? We’ll have to run electrical wires to all those villages; I suppose that’ll keep someone busy.

        • Darin says:

          I’ve always taken carrying capacity estimates with a grain of salt since they tend to have extreme assumptions in terms of the global average lifestyle. Since most population growth is happening in areas with relatively little per capita resource consumption and impact, whenever I see people from the G20 complaining about population growth in poor nations I always think it’s too close to saying that those poor people on the other side of the globe shouldn’t have kids so that the wealthy can still continue to live relatively lavish lifestyles.

          If someone was restricting their comment to population growth in wealthy nations and included the caveat that the average American or European consumes ~5-30 times more than the average member of most countries with high population growth rates, then I think it’s a reasonable thing to say.

        • Frederik De Roo says:

          Darin said:

          I always think it’s too close to saying that those poor people on the other side of the globe shouldn’t have kids so that the wealthy can still continue to live relatively lavish lifestyles.

          I don’t understand your point very well. I think the wealthy will have to adopt their lifestyles regardless whether the poor people grow in number or not.

          But of course they’ll have to adept it a lot more if the poor people start to become less poor (which would be fair, I think).

          If someone was restricting their comment to population growth in wealthy nations

          I’m not an expert on this issue but I believe the population growth in wealthy countries among a large part of the citizens (except those at the lower sports of the social ladder) is very low.

          Note: I do agree that, for G20 inhabitants, there should also be emphasis on lowering their footprint. But, I wasn’t suggesting “one best thing” ( I was just commenting other suggestions) because I don’t think there is one best practical thing to be offered that’s useful for everyone.

        • Darin says:

          Don’t look too much into it Fredrick! ;) I just get worried when I see discussion of carrying capacity in terms of population (w/o mentioning global average lifestyle) because I’ve seen certain forms of media labeling the environmental problems we’re facing as primarily due of population growth (mostly public radio/broadcasting).

          I don’t think anyone posting on this blog entry believes our issues are primarily due to population growth, especially w/ ~1 billion people in the wealthier world causing roughly the same impact as the other ~6 billion, but when I see someone posting about carrying capacity solely in terms of population I cringe because I know someone else can come along and interpret it that way.

      • John Baez says:

        Eric wrote:

        If these are the types of solutions you guys take seriously, then no wonder no one pays attention. It makes me wonder why I am paying attention.

        Unfortunately the people here are answering the question that was actually asked: “What is the one best thing everyone could do to slow down climate change?”

        A question like “What is the best politically realistic approach to slowing climate change?” would have a completely different answer.

        As we compose the official Azimuth Project answer to this question, we’ll have to point this out, or people will think we’re kooks. I’ll say more about that momentarily.

        By the way, Eric: what would your answer be, to the question that was actually posed?

      • Mike Stay says:

        How about “educate women”? Numerous studies have shown that educated women drastically reduce the number of children they have.

        • John Baez says:

          Thanks, Mike! That’s another good answer, one that I’ve at times suggested.

          When I tried to find these ‘numerous studies’, I had a trouble getting convincing evidence. People usually point to papers put out by the World Bank girl’s education project. But when you try to get to the hard data it seems hard to separate the effect of educating women from the effect of other things that tend to happen in concert with this. Some question whether educating women is the key factor.

          So, while I like the idea of educating women—which is obviously a good thing for lots of other reasons—I’d really enjoy seeing more evidence.

          I certainly believe that education is preferable from a human rights perspective to the Indian sterilization policy—I guess that goes without saying. A more interesting thing to compare it to is the Chinese ‘one child policy’, which seems actually to have been quite successful, despite or because of the infringement on human rights it entailed. In general I’ve found Americans to be more outraged by this policy than the Chinese, who tend to regard it as a necessary evil.

    • Tony Vladusich says:

      ah yes, but what if my child is the one who solves the world’s energy problems by contriving some new green energy source? ;-) (no pressure, Amelia…i know you’re only 13 days old!)

      • Giampiero Campa says:

        Jokes aside, this way of thinking seems to be widespread in particular among economists (I don’t want to generalize, just telling my experience).

        While there is certainly some merit to it, (as population boom and interconnections have surely contributed in fueling last century’s growth and tech development), I personally feel that getting rid of this way of thinking could make it in a list of 100 best things you can do for the environment :)

        Basically i think that relying on an undiscovered technology to bail us out is just wishful thinking.

      • John Baez says:

        Giampiero wrote:

        Basically i think that relying on an undiscovered technology to bail us out is just wishful thinking.

        Right. This is widely accepted among people who are serious about confronting global warming.

        Dreamers imagine a ‘silver bullet’ that will solve all our problems painlessly. But the problem is that it’s essentially impossible to scale up any brand-new technology fast enough to bring CO2 emissions down to where they should be soon enough to avoid trouble.

        Joe Romm has written a lot about this. Here Alex Krogh-Grabbe’s nice summary, written in 2009. You’ll note that he says there is no silver bullet, just many different things we must do quite quickly—and “we must have substantial action before 2012 or we’re toast.”

        The solution is centered around achieving ~14 “stabilization wedges”. One wedge = one billion fewer metric tons of CO2 emitted globally, compared to projected levels. Again, this is possible with current technologies, and has a net cost of zero. The basic strategy is to replace all coal as quickly as possible, and to electrify transportation as much as possible.

        Though there’s no silver bullet, but there is “one” solution: we must deploy every conceivable energy-efficient and low carbon technology that we have today as fast as we can. In order to reach the target carbon concentration of 350ppm, we have to deploy all 14 wedges of energy savings by 2040. Though increasingly serious implementation will begin soon, starting around 2030 multiple climate-caused catastrophes will cause drastic measures unthinkable today to be implemented. We must reverse the trend of increasing emissions by 2015-2020 at the latest, and we must have substantial action before 2012 or we’re toast.

        There are about 18 wedges possible, and we need about 14 of them to succeed. Here are the options:

        Currently available (14.5):

        • 1 wedge – albedo change through white roofs and pavement ( “soft geo-engineering” )
        • 1 wedge – vehicle efficiency: 60mpg standard for all cars, no increase in miles driven
        • 2 wedges – wind: two million large wind turbines
        • 3 wedges – Concentrated Solar Power aka Solar Baseload
        • 3 wedges – energy efficiency: one each for buildings, industry, and cogeneration/heat-recovery (also geothermal heat pumps)
        • 1 wedge – solar photovoltaics (PV)
        • 2 wedges – end deforestation AND plant new trees covering an area the size of the United States
        • 1 wedge – massive conservation post-2030
        • 1/2 wedge – nuclear (more not plausible, and it’s expensive, too)

        Requiring more R&D (4):

        • 1 wedge – geothermal & other ocean-based renewables (wave, tidal, ocean thermal)
        • 1 wedge – coal with biomass cofiring WITH carbon capture & sequestration (more not plausible, and it’s expensive, too)
        • 1/2 wedge – next-generation nuclear
        • 1/2 wedge – cellulosic biofuels for long-distance transport & remaining aviation
        • 1 wedge – soil & biochar
  2. DavidTweed says:

    A bit of a “cheating” answer but…

    The first thing that people with weight or financial problems are recommended to do is keep a record of their eating/exercise or spending/income respectively, on the grounds that you can see what the big problems that you’ve got (as opposed to the problems of the mythical Mister Average). So one suggestion is to keep a record estimating the environmental effects for a couple of months and read through it occasionally. Maybe doing this will lead to both the decision one should do something about environmental impact, and give an idea of what the low-hanging fruit in one’s life is.

    (Not gonna work like that, I know.)

    • Martin says:

      There is a project that promotes a double price-tag policy: one price that you have to pay and another price-tag saying what the good actually costs (or should cost). The latter price has no influence other than psychological. Personally, I think it would be extremely good to have this. Of course, one of the main problems with it is to assign prices in a reasonable way, but I think it should be possible to sort this out. http://www.futuro-preise.at/

      Apart from that, I think that in large parts of the world the way homes are built is a major issue, not only with respect how they are built, but also where.

  3. Thomas Fischbacher says:

    Climate change essentially is about resource mis-management. Basically, the underlying problem is that we are using a linear mining/extraction-combustion-pollution process, on a very big scale. This cannot go on for a number of reasons, climate change being just one symptom. Note that we do this in order to provide for our needs. Consequently, if we want to make a change, we have to learn how to provide for our needs in such a way that fossil fuels play a much less important role.

    So… how do you produce things like food, clothing, shelter, etc., without using fossil fuels? If we want to rely less on stuff that grew millions of years ago, we have to learn to do more with the stuff that we can grow now.

    Hence, the sort-of obvious answer is: learn to garden, and make sure you do get good at it.

    And that’s something which indeed pretty much everybody can do, regardless of how rich or poor they are, where they live, or what their culture or religion is.

    There is a second independent reason for the importance of gardening: it gets you in touch with reality in a way few other activities do. Most of what we spend time with happens in a highly artificial environment dominated by human concepts that have no direct physical representation. When you watch TV or play a computer game, neither the images nor the dialogues nor the emotions are real. These are completely artificial worlds. Living in artificial worlds definitely has a damaging effect on one’s judgement capacity. (A specific example: it’s very interesting to hear paramedics talk about the insane widespread misconceptions about first aid issues caused by TV. No, cars do not explode violently a second after a fire breaks out.)

    If you want to live and make a difference in the real world, you have to calibrate your judgement against the real world, not Hollywood. I hardly can think of a better exercise to do so than to garden.

    • John Baez says:

      Great point, Thomas. Alas, I couldn’t really have understood what you’re talking about before I started gardening myself!

      Your interview will show up on This Week’s Finds pretty soon, I promise. I’m sorry it’s taken so long.

  4. Phil Henshaw says:

    I think the actual problem, and why it’s so intractable, is that our “resource management system” is designed to serve our financial system,… not the reverse.

    Our financial system is designed to create stable positive financial returns, so people can keep adding their winnings to their bets, and have an ever multiplying “free lunch”. The critical energy management decision necessary for doing as best one can at that (allowing punctuating the endless boom with enough busts all the time…) is to accelerate the economy’s use of inexpensive energy as fast as economically feasible, forever.

    What results when people model their implementation of physical law following rules they happen to like for financial law, is it creates a simply enormous explosion of wealth that produces a completely unmanageable society and economic system (instead of a comfortable home on earth).

    I think that’s a big part of what is so self-defeating in the human intention to “tame nature” to behave like we think it should. We haven’t seen the value of watched nature to see how it works first.

    • John Baez says:

      Can you translate these insights into an answer to the question: “What is the one best thing everyone could do to slow down climate change?”

      If so, would the answer be some version of “think differently”? Or is there a concrete action that you can propose?

      • Phil Henshaw says:

        The theoretically necessary step, that no one seems to understand when stated in abstract terms, is for the net-energy surplus that was first applied to growing the system, now be applied to adapting the system to a finite and fragile planet. The world’s institutional economic models and planning assumes there will never be a need for that, and money can keep compounding forever.

        The practical means of changing that comes from J M Keynes, and what to do with money when the economy can’t grow. It follows from how the surplus resources for growing the economy were managed to start with, by the use of profits from investment to proliferate more investment. To keep investment funds from becoming worthless when the economy can’t grow, and make the system manageable again, you’d need to deflate that money spiral. As a personal matter it means the people whose money it is need to stop growing it, and be careful to invest it in good purposes.

        That would involve a) devoting investment funds to sustainable development rather “fast money” and b) stop adding investment profits to expand total investment, divesting net profits for some other good purpose. There would be a lot of negotiation as to how to achieve that, of course, as all our institutional plans assume it’ll never occur.

        I’ve been getting traction with some of the leading thinkers in the ethical investment community (John Fullerton, Hazel Henderson and others) by saying it’s a matter of combining “green investment” with “green divestment”, redirecting the savings in the “giant pool of money” for good purpose, to reduce the absolute scale of our demands on the earth.

        Keynes actually wrote a whole chapter of his big book on it, though due to the cultural belief in perpetual growth his entire profession ignored it completely. I have a scanned copy here. It’s readable, but you have to fight through his discussing it in terms of the aggregate variables of the world economic system, entirely ignoring any social or political debate… To find my references to that, and to “the widow’s cruse” parable he first discussed in in terms of, you can browse my blog posts mentioning Keynes.

        Phil

  5. John Baez says:

    So, here’s a possible start of an answer. What do you folks think?

    The question as phrased — What is the one best thing everyone could do to slow down climate change? — pushes us toward extreme answers that are not politically or economically realistic.

    If “everyone” truly means everyone, even the billion poorest people on Earth, many answers are automatically ruled out.

    Fly less? For some of us, taking one less airplane trip per year is the least painful way to cut back on CO2 emissions — but the billion poorest people don’t take airplane trips. Drive less? They don’t have cars. Eat less beef? Cattle are a hugely inefficient way of turning sunlight and water into protein, and they emit vast amounts of methane, a greenhouse gas far more potent than CO2 — but the billion poorest people don’t eat much beef. And so on.

    The one thing that everyone could do to slow down climate change is reduce population growth. From 1980 to 2007 the world-wide usage of power went up 60%. Power usage per capita went up only 10%. But the Earth’s population went up about 50%. So here’s the one thing everyone could do: slack off on having kids. If you want children, consider adopting one!

    However, what everyone could do bears little relation to what most people will do. In reality, global warming will not be stopped by one single measure. If we succeed in getting a handle on it at all — a bit if — it will be by doing many things simultaneously.

    And then I’d like to list 1 measure, or maybe 2 or 3, that individuals can take and are likely to actually do. I see a few being proposed so far:

    • keep track of your carbon emissions.

    • practice gardening.

    • practice biochar (especially good for people who are too poor to do fancier things).

    What are the best?

    • Steve Bloom says:

      Hmm, but e.g. people already too old to have children can’t participate.

      My thought: Remove from positions of influence anyone who doesn’t take the problem seriously.

      • John Baez says:

        Steve wrote:

        My thought: Remove from positions of influence anyone who doesn’t take the problem seriously.

        That’s a good one. Lately I’d been leaning towards “Become deeply knowledgeable about the issues and take action accordingly”, which is perhaps unsatisfying for people who want to be told what to do, but covers a lot of ground.

      • Florifulgurator says:

        I applaud Steve’s thought. We can no longer afford numbskulls in office. It is an obvious, first and basic thing to do: No more intellectual mercy!

        Self-evident corollary: Register climatevote.org and build a WWW database of politicians with quotes and classification.

  6. nad says:

    In countries with a good health and elderly care and a good education birthrates usually decline automatically.

    Here in Germany (and in most western Europe) the birthrate is rather so that population is/will decline rather soon. In the United Nations Press release one finds that if

    “The low variant, whose fertility remains half a child below that of the medium, produces a population that reaches 8.1 billion in 2050 and declines towards the second half of this century to reach 6.2 billion in 2100. “

    I couldn’t find their definition of medium (its also no in the glossary) but I assume the above means 1.5 kids per couple? Which would be about the birth behaviour of an average European country. So before thinking about castrating, one should may be start to care about better social and cultural conditions (like promoting birth control and the education of women).

    by the way gardening per se is not necessarily climate friendly…especially not if you have big grass, which has to be constantly watered and mowed with a tractor.

    • John Baez says:

      Nobody was suggesting castration, Nad.

      But if we were looking for the least politically viable solution to global warming, I think you just found it.

      By the way gardening per se is not necessarily climate friendly…especially not if you have big grass, which has to be constantly watered and mowed with a tractor.

      Indeed, huge lawns are an utter horror, especially in places like Southern California, where water is scarce. This golf course in Palm Springs may look beautiful to some, but it makes me want to puke:

      Set amidst a subtle natural landscape we have a garish artificial playground that only survives with the help of constant maintenance, fertilizer, and huge amounts of water brought in from afar.

      When you get to know Thomas Fischbacher you’ll see he’s advocating the sort of gardening that makes you think about how natural systems work, and learn to cooperate with their tendencies instead of fight them.

      • nad says:

        John wrote:

        Nobody was suggesting castration, Nad.

        I used the word “castration” for putting the word “sterilization” in a more concrete format.

        So what was then meant by e.g. Florifulgurator:

        “Plan B: It seems soon the only sapient solution would be mandatory mass sterilization with a lottery to pick out a few fertile humans for the bottleneck population.

        And coming back to my comment from May 28:

        “In countries with a good health and elderly care and a good education birthrates usually decline automatically.”

        and your comments…

        Mike Stay wrote:

        How about “educate women”? Numerous studies have shown that educated women drastically reduce the number of children they have.

        John Baez wrote:

        Thanks, Mike! That’s another good answer, one that I’ve at times suggested.

        When I tried to find these ‘numerous studies’, I had a trouble getting convincing evidence. People usually point to papers put out by the World Bank girl’s education project. But when you try to get to the hard data it seems hard to separate the effect of educating women from the effect of other things that tend to happen in concert with this. Some question whether educating women is the key factor.

        So, while I like the idea of educating women—which is obviously a good thing for lots of other reasons—I’d really enjoy seeing more evidence.

        Seeing more evidence is especially difficult if a lot of links on the Gender Stats website are broken.

        By the way grassland needs far less water if there is enough shade, like from trees and if its kept long.
        So may be one could suggest as an alternative to golf parks in southern California shady mini-golf parks embedded into more or less urban prairies? It may however be rather expensive to start out with planting big trees in southern California…

      • John Baez says:

        Nad wrote:

        It may however be rather expensive to start out with planting big trees in southern California…

        Right now landscape design in southern California is based on the availability of cheap water from the Colorado River and northern California. If we keep having droughts like the 3-year drought that just ended, that may change.

        It’ll be easy to make lots of improvements. In my neighborhood people are starting to remove their lawns and do xeriscaping instead. We did it a few years ago: it’s great!

        Also, people are gradually learning that it’s ridiculous to plant palm trees in southern California. They use a lot of water and provide almost no shade. They’re not native to the region, either—at least, not the kind you see here:

        (Click the picture to learn more about what’s wrong with palm trees.)

        Now, on to everybody’s favorite subject…

        Nad wrote:

        I used the word “castration” for putting the word “sterilization” in a more concrete format.

        But that’s like using the word “decapitation” to make the concept of “haircut” more concrete. Yes, that’s one way to remove someone’s hair: just chop off their head! But honestly, there are much better ways. You know about vascectomies, right? Guys have them voluntarily.

        • Phil Henshaw says:

          There’s also the problem with using forest. To use it for sequestration you need to produce new mature forest at a rate of one additional acre for every 200 thousand dollars of GDP. So a person making $100k would, on average, need to purchase, plant and maintain another half acre of forest land, every year, and provide an endowment to maintain it and pay rent and taxes in perpetuity. That’s to capture and secure their annual CO2 pollution at the average rate per dollar of GDP.

          http://www.synapse9.com/design/ForestSequestration.xls

        • Thomas Fischbacher says:

          Unfortunately I cannot reply directly to Phil Henshaw’s comment, so I have to reply one level up the thread.

          1. This half acre of forest land can be anywhere on the planet, right?

          2. If the natural vegetation was forest, then the expectation would be that an established forest eventually should be able to pretty much take care of itself, right?

          3. There is a funny way to not only do precisely this, but in even such a way that this works as a way to reduce the tax load. Basically, the idea is: (1) You cheaply buy some seriously degraded land somewhere. This creates expenses for your business. (Let us assume your actual business does not have the slightest interest in land management.) (2) You pay a few land restoration experts to turn infertile devastated land back into fertile forest. This generates further business expenses. (3) Over time, degraded land returns to forest, and the value of the land now would be much higher than it was beforehand – but you actually neither want to hold on to it nor want it to be turned back into CO2, so you donate it at its market value(!) to an environmental charity set up by the land restorers you hired in (2) who make sure this stays forest.

          Let’s say you spent $20000 on land and wages for the restoration team, which in the end allows you to donate forest of a value of $100000 to a charity. So, you spent $20000 of actual money to in the end reduce your tax load by $120000. Let’s say your business pays 25% taxes. That means that by spending $20000 in total, you reduced your taxes by $30000.

          The numbers are not correct, but well, you get the basic idea. Such a scheme can indeed be made to work.

        • Thomas Fischbacher says:

          There is a slight oops in my above posting. Obviously, one must not count the expenses for land twice. So, let’s just (conservatively) forget about wages as well and say you spent $20000 to make a donation worth $100000 which gives you a tax break of $25000. Effectively earned $5000.

        • Thomas, looks you got quite the same grand picture as I have.

          Your restoration teams (precursors of the repair species Homo Eusapiens) are at the heart of my Plan C. They not only produce forests (e.g. reforesting Haiti). There’s enough depleted/mineralized agricultural land in need of a buildup of humus.

          As you demonstrated, restoration teams make economic/investment sense even in today’s framework. (Phil can add more). Here in Bavaria there exists at least one rich man who invests in agricultural land and might want to lend it to a restoration team. (From the global ecosystem perspective, restoration means natural carbon sequestration by building up soil carbon. That can be anywhere, even on relatively good agricultural land. Use biochar to speed this up and make carbon sequestration more stable and less vulnerable to climate weirding.)

          But there’s also an individual economic incentive to join a restoration team: Food sovereignty independent of money (pension funds, etc.)

          Ethic reasons to join or support a restoration team would also be abundant. (E.g. I wonder when Mahayana Buddhists will form restoration teams en masse, noting the fundamental challenge to their ethics of compassion with life: Not carbon negative, no bodhisattva. Not carbon negative, no sangha.)

        • Thomas Fischbacher says:

          Florifulgurator,

          Who in Bavaria are you talking about? (Incidentally, I am a Bavarian, too.)

          Maybe I should add that repairing ecosystems can be learned; there is a lot of information out there, and there are numerous people with a lot of practical experience. When I’m not busy with my University work, I’m also experimenting with some techniques, giving courses, and doing a few other things to spread knowledge about what can be done.

        • Thomas, I haven’t yet asked who said Bavarian is. Somewhere near Passau.

        • Phil Henshaw says:

          I think the two things I’d point to are the need to return an *additional* half acre of land to wilderness to become mature self-sustaining forest, for *every* $100K a business earns. Say the business you’re going to sequester the carbon of is “the world economy”, with its $60t income to compensate for. At the world average CO2 production rate that would require a permanent set-aside of 600billion acres of high quality new forest land a year, and more than that if it costs any money to do it.

          Things that are out of scale with our familiar units are indeed hard to catch on to at first, as nearly everything about a perpetual global growth system becomes. For this one you’d need to then look and see exactly what lands would be used for the set-aside, and whether any expense would be involved. 600billion acres a year to set aside sounds to me like quite a lot.

        • Thomas Fischbacher says:

          Yes, one additional acre per $200K. I am talking about the same thing.

          But, as I said, it can be anywhere on the planet. I see little reason, for example, why one could not continue doing what Lugari did in Colombia on a much larger scale.

        • Florifulgurator says:

          Oh! Gaviotas, Colombia and Paolo Lugari… Stuff for Plan C. Another more extreme vision I have is reforesting Haiti (starting near the Dominican Republic’s border for food and soil supply and forest nursery), seeded by small scattered extreme-eco communities.

          We need billions of folks living in sustainable “eco” villages. They are the future’s carbon sequestrators (biochar, forest gardens). (If hominids are any interested in any future…) Plus, they provide food security for the poor and escape from the megacities.

          Agriculture is the key to the future, biogeophysiologically as well as socially. A parallel world in symbiosis with megalopolis.

  7. G.R.L. Cowan says:

    Governments tend to say they can’t expedite approval of new nuclear construction because of the supposedly irrational public’s supposedly impenetrable opposition.

    They, the governments, are therefore forced, quite against their will, to allow natural gas combustion turbines to be rapidly built and to thereafter bring in huge natural gas royalty revenues.

    I think blaming this on the public is blaming the victim, and therefore my idea of one helpful thing to do is wear my Nuclear Power Yes Please button. A physical button, visible by people out in space, away from the terminal.

  8. Eric says:

    One thing Azimuth might be able to help with is convincing people there are problems. You’re looking for solutions for things that are not obviously problems. Quantify.

    • John Baez says:

      Good point. I don’t think this is the best question for eliciting information that’ll convince people there’s a problem, but we can try. There will be many questions to come of a more factual nature, which we can more easily answer with facts and figures.

    • John Baez says:

      By the way, Eric… I asked you up above but you may not have noticed… what would your answer be to this question:

      What is the one best thing everyone could do to slow down climate change?

      • Eric says:

        Missed that.

        Question: Why should we want to slow climate change? Maybe climate change is good.

        If we destroy the planet, it will destroy us. Maybe that what is needed.

        • John Baez says:

          That’s a very interesting question. But can you try answering the original question to the best of your abilities… just for fun? Humor me.

        • Eric says:

          I wish I could answer, but I’m not qualified. I doubt there is anyone qualified to answer this question. The best I can do is ask questions.

          Define climate change. If every human was suddenly teleported off the earth, the climate would still change. That is what climates do. Who am I to slow it down? How do you know the climate wouldn’t change faster if humans were completely out of the picture?

          Do you mean, “what could everyone do that would slow bad climate change (as opposed to good or natural climate change)”?

          Define bad climate change.

          What is the goal? To do something good for humans or something good for the earth? The two may not be the same.

          Sometimes, e.g. Coley’s toxins, the introduction of a deadly virus, I.e. humans, can help with other ailments.

          We don’t even understand the health if the human body. How are we to understand the health of the earth.

          These are the kinds of questions I hope Azimuth can starts answering.

        • John Baez says:

          Eric wrote:

          How do you know the climate wouldn’t change faster if humans were completely out of the picture?

          Obviously the full answer to this question is very long, with many arguments to be had along the way. But the quick answer is this graph I displayed at the very start of this conversation, back in week301:

          You can see several ice ages here — or technically, ‘glacial periods’. Carbon dioxide concentration and temperature go hand in hand, probably due to some feedback mechanisms that make each influence the other. But the answer to your question is the vertical line on the right where the carbon dioxide shoots up from 290 to 390 parts per million in about a century! This change is essentially instantaneous from a geological point of view. It’s carrying the Earth out of the climate regime it’s been in for the last 20 million years or so, and it’s just beginning: with ‘business as usual’, that vertical line will go up roughly twice as high by the end of this century.

          Thus, we have left the Holocene and entered a new geological era: the Anthropocene

          Do you mean, “what could everyone do that would slow bad climate change (as opposed to good or natural climate change)”?

          I didn’t ask the question: Curtis Faith did. I can’t be sure what he meant, but:

          The rapid climate change we’re starting to see now will be disruptive to ecosystems and thence to human civilization, by sheer force of its rapidity if nothing else: a sufficiently rapid change in any direction makes it hard for natural systems to adapt. Thus, it makes sense to ask about how to slow down (though of course not prevent) climate change.

          I will write an answer to this question and move on to other questions: preferably ones that are a bit factual in nature, and thus a bit easier to handle. However, this big tough question was not so bad for initiating a discussion…

        • Eric says:

          How do I know your “scare chart” is accurate? How big are the error bars? How do they get data going back so many thousands of years with the accuracy implied by observing the data?

          If you had shown me this chart 140,000 years ago during the previous spike, I would be similarly “scared”.

          How do I know you are not looking for data to support a preconceived notion? Is it possible someone could present a similar scare chart making the exact opposite argument?

          Even if I accept the chart as being accurate, how scared should I be?

        • William T says:

          If you had shown me this chart 140,000 years ago during the previous spike, I would be similarly “scared”.

          Actually, if you zoomed in the 140ky “spike” it would look nothing like the present spike – it was a slow and steady rise over several thousand years. Today’s spike is occurring over a century or two.

  9. Eric. Maybe, but never underestimate collective intelligence they built wikipedia dbpedia and many open source projects. So I’d put few quantifications.

    BTW how do with deal with global social and economic heterogeneity and cumulative responsibilities?

    • John Baez says:

      I’m afraid this simple question does not take heterogeneity into account (different people should do different things), nor cumulative responsibilities. It seems to be asking what one thing every individual could do that would maximally slow global warming.

      Suppose we leave out illegal activities. Then what would your answer to this question be:

      What is the one best thing everyone could do to slow down climate change?

      I’m just curious. Don’t worry, later we will do some easier questions.

  10. Alpha Omega says:

    Does anyone really think problems on this scale are going to be solved by the ivory tower ideas of educated do-gooders? I suspect those days are almost over. My model for the future is one of global resource wars and uncontrollable chaos, somewhat like the Eurasian Migration Period of the early Dark Ages, but global this time, with our much larger populations and more disruptive technologies making things far crazier.

    I expect at some point fairly soon the world’s elites will give up on saving the vast billions and will circle the wagons around those pockets of advanced civilization that can survive the chaos. In fact I suspect a lot of them have already given up, and are making preparations for the chaos as we speak. I think the future will be quite shocking for those who cling to the failed progressive ideologies of the past, and expect that much harsher solutions to our Malthusian challenges will be forthcoming as the world unravels…

    • DavidTweed says:

      Does anyone really think problems on this scale are going to be solved by the ivory tower ideas of educated do-gooders?

      It’s very difficult to tell. My personal “World War II analogy to environmental problems” isn’t the Manhattan Project (which seems popular with a lot of people) but the general British population’s behaviour during WWII. With a problem that was almost universally believed to be genuine, there was all kinds of things like conservation of resources (including pretty much acceptance of rationing), scrap drives, a lot of making do with limited resources, forming new social networks, exceptional actions in the face of exceptional circumstances (eg, Dunkirk evacuation).It was even, in common with WWI, a time when attitudes changed dramatically (women’s role) when it became clear circumstances forced it. There were certainly those who maintained their previous prewar behaviour or even took advantage of the situation (profiteering, black market, etc), but the overall percentage of the public action was pretty amazing. (I’m sure there were similar things happening in other countries, I’m just familiar with Britain.)

      You could argue about why even a fraction of this isn’t happening now. It might be that society has changed, becoming more self-focussed, but I wonder how much is more due to the degree to which it’s visible the environmental dangers: if bomb’s are dropping and you know someone (maybe even yourself) who’s received a letter informing them of a soldier’s death, it’s difficult not to “believe” that an incredibly serious threat exists. In contrast, for environmental problems it’s currently at the level of precursors which it’s easy to dismiss or quibble with.

    • John Baez says:

      Alpha Omega wrote:

      Does anyone really think problems on this scale are going to be solved by the ivory tower ideas of educated do-gooders?

      Did anyone really say that?

      Your points are interesting and worth discussing. Nonetheless, I would like to know your answer to this question:

      What is the one best thing everyone could do to slow down climate change?

      I can think of lots of reasons why the answer to this question will have little to do with what actually comes to pass, why it’s a bad question, etc. But just for fun: what would your answer be?

      • Alpha Omega says:

        Well everyone isn’t going to do anything, so the point seems pretty moot. But if we want to fantasize, I would think that if everyone in the industrialized world cut their consumption of everything by about 75%, switched to solar everything and starting riding bicycles everywhere that this would have a pretty big impact. If California wants to lead the way, they should be building bicycle superhighways and all those Hollywood limousine liberals and Washington jet-set environmentalists should start riding bikes and setting examples for the cool new low-consumption green lifestyle. Some kind of quasi-Maoist green cultural revolution in the first world might actually work. Like I said, this is all fantasy, but those are some of my ideas.

        • John Baez says:

          Thanks! I’m not sure that counts as ‘one best thing’, it sounds like a lot of things, but that’s okay: this question seems particularly hard to answer without changing it slightly. Needless to say, I don’t mind that your suggestion is ‘all fantasy’, because the question didn’t impose any constraint that the answer be something that people are likely to actually do.

  11. John Baez says:

    Frederik wrote:

    That’s something everyone can do but not what everyone should do.

    I’d prefer to rephrase it to “have not more than two children.”

    Darin wrote:

    If someone was restricting their comment to population growth in wealthy nations and included the caveat that the average American or European consumes ~5-30 times more than the average member of most countries with high population growth rates, then I think it’s a reasonable thing to say.

    It’s true that the countries with high carbon per capita carbon emissions tend to be different from the countries with high birth rates. The advice to not have fewer kids would of course be more productive if this were not the case.

    However, what would your answer to this question be:

    What is the one best thing everyone could do to slow down climate change?

    It’s a difficult question. If we imagine everyone joining together as a team, there are a lot of things we could do collectively that would have a huge impact. But my interpretation of the question is: what one activity can we choose, that any individual on Earth can do, that would maximally reduce carbon emissions?

    Perhaps this is a bad interpretation. But given this interpretation, it seems that, sadly, not bringing another human being into existence is the answer.

    Of course, in reality, the best thing to do varies from person to person. So, it may be more productive to ‘unask the question’ and point this out.

    • Frederik De Roo says:

      John said:

      what one activity can we choose, that any individual on Earth can do, that would maximally reduce carbon emissions?

      Perhaps this is a bad interpretation. But given this interpretation, it seems that, sadly, not bringing another human being into existence is the answer.

      As I already wrote earlier sarcastically, I think instead that committing suicide would reduce carbon emissions maximally (perhaps in combination with sinking the dead body to the bottom of the oceans, such that the body carbon will be captured and not released). I’ll add again that I do not want to propose this as my personal answer but that doesn’t mean it couldn’t be the maximally efficient solution that any individual could do.

      • John Baez says:

        I we should go ahead and add some implicit fine print to the question saying that the activity proposed must be both legal and (much more tricky) moral, since the question says ‘best’. I think this will rule out ‘unacceptable’ answers like suicide, killing as many people as possible, or blowing up coal-burning power plants.

        But anyway, what is your personal answer? I’m not sure you gave it. Don’t worry, you’re allowed to change you mind as many times as you want, and I’ll even delete your comment on the blog if you decide some answer was embarrassing and you wish you hadn’t said it. I will not make you actually do the activity you propose. I’m just trying to collect some interesting possible answers.

    • Darin says:

      I totally missed this, so disregard my last post. Excluding any group activity, I agree that delaying having children such that the population stays at roughly it’s current level has the potential for the greatest impact on future GHG emissions.

      That said, since you mentioned morals I think it wouldn’t be as likely to succeed as something like minimizing/eliminating meat/dairy from our diets since there may be religious implications to delaying children for decades, and for some people in a certain age group, not having children at all.

      I’m not sure if the product (or whatever concept is suitable here) of the percentage of people who would likely delay having children with the associated per capita GHG emissions is greater than the product of the percentage of people who would minimize meat/dairy consumption with the associated reduction in per capita GHG emissions. I can’t really pick one or the other w/o more research, but I guess my point is that IRL it may be a lot more complex than just picking something that has the greatest potential w/o looking at how many people are likely to comply w/ a suggestion.

  12. John Baez says:

    Jesse McKeown has placed his answer to the question on Quora. That’s a good idea. I think it’ll be fun and enlightening for us to attempt to collectively figure out answers to questions, but there’s no need to speak with one voice. On the contrary, if there’s disagreement it’s good for people on Quora to see it. I think you need an invitation to join Quora. If you want one, send me an email: if I know you and think you’re a reasonable being, I can probably figure out how to send you an invitation.

    Jesse wrote:

    Because I am not the azimuth project nor wish them to represent me, I will suggest that the one best thing everyone can do to slow down climate change — supposing climate change to be a bad thing everyone can do something to slow down, that is — is to learn to recognize, prize, and practise virtue.

    Of particular importance will be those facets of virtue known as self-control or self-restraint — the government of reason over the passions, that is — and proper obedience to authority.

    One useful exercise in acquiring the practise of virtue in respect of self-restraint is the deliberate sacrifice of unnecessary comforts. This may be aided by practising a habit of contentment — of finding happiness in simple necessity. Particularly, one should regularly make a habit of eating what food one knows to be sufficient, whether you still feel peckish afterwards or not; of moderation and prudence in lovemaking; of wrapping up in the cool when heating is not needed, or dressing lightly and keeping to shade when air-conditioning is not needed; of spending only what one must of the money one actually has; of speaking politely in polite company. Spinoffs abound.

    Now, when I say this is something everyone can and should do (I hope that’s obvious anyways, but still… ) I really do mean everyone. I mean the poor farmers and the poor bankers, and the rich bankers and rich farmers, and carpenters and biologists and private soldiers and generals and bureaucrats and governors and sons and daughters and parents and hermits and … And by authority I mean not only legitimate offices, but authentic true wisdom, consciences well formed and safe engineering practices. Heavens forefend, there may come a time when, for the good of the planet, it is really found prudent that a billion people have their roofs white-washed, so to increase the ground albedo and cool the earth. (this seems like a fair example, as it is simply coordinated and reasonably reversible); in such an event, it were obviously advantageous if a billion or so people can be found who will assent to the call, and that not a million hinder the project in painting all their roofs dark green!

    But it’s equally important that any decision to whitewash a billion roofs not arise from some influence of the lime-and-chalk industry, but from a genuine need to make certain regions of the earth more reflective. And so, anyone calling the shots ought to be really informed by such advisors as ought to know, and the advisors ought really to be delivering true knowledge and neither wishful thinking nor self-interested deceit.

    Other examples will occur to you.

  13. Speed says:

    The process of improving quality starts with measuring the thing you want to improve. In many cases, letting the responsible people know how good or bad a job they’re doing and giving them a reliable metric to monitor results in improvement.

    “What is the one best thing everyone could do to slow climate change?” Monitor their monthly fossil fuel usage.

    Background on the CO2 emissions “problem”
    By far the largest US source of CO2 emissions is fossil fuel combustion.

    http://www.epa.gov/climatechange/emissions/co2_human.html

    And fossil fuel combustion is mostly for electricity production and transportation.

    http://www.epa.gov/climatechange/emissions/co2_human.html#fossil

    The answer
    So … to make any meaningful reduction in US CO2 production requires meaningful reduction in electricity use and/or transportation use. The first thing everyone should do is monitor their use of electricity and transportation fuel.

    And I were king …
    If I were king and wanted to lead (not force) people to make meaningful reductions in electricity and gasoline/diesel use I would first generate monthly reports for each and every household with two numbers – how much fossil-fuel-generated electricity did you use last month (with historical data) and how much gasoline/diesel did you use last month (with historical data).

    Most of the data is already floating around in the digital universe. Your electric company sends you a bill every month with the information printed on it. Not prominent. Not meaningful to most people. Apply a little marketing magic so people see and understand the numbers.

    Most gasoline is purchased from a high tech pump using a credit card so your credit provider of choice could provide the relevant data in usable form.

    And if I were king, my second act would be to fund a marketing campaign that drives (leads?) people to make meaningful reductions in their fossil-fuel-generated electricity use and fossil fuel transportation. Marketing is a powerful thing – and it’s cheaper than ethanol subsidies.

    The above assumes that climate change is a CO2 related problem.

  14. Darin says:

    I think it’s political pressure, since politics is the biggest impediment to making significant reforms in how we do anything. It doesn’t matter how poor someone is, they can always try to know what’s happening to the environment in their corner of the world.

  15. Martin says:

    Here is my real answer: practise empathy and awareness. (this may not be completely correct english, please bear with me)

    The reason for this belief is: it seems to me that most technological solutions for problems of the past failed to solve the actual problem in the long run, or at least introduced new, possibly unexpected, problems. Cars have been a great success, so was nuclear energy. Even modern medicine has drawbacks.

    I am certainly not saying that all this inventions are bad and we should try to turn back time. My feeling is that mankinds technology is evolving much more rapidly than mankinds ability to solve social problems. This in turn means we need to improve the latter ability (rather than abandon technological progress).

    Besides, there are at least two things I believe have helped mankind without introducing (heavy) new problems: canalisation and modern communication technologies.

  16. John Baez says:

    Okay, what follows is another draft of the official Azimuth Project answer. I have put this on Quora, just out of an impatient desire to get the job done, but I can change the answer there in response to further criticisms.

    Later we may adopt a more bureaucratic procedure for answering these Quora questions, if people start to take this game enough to demand that the answers represent a consensus among the people reading this blog. I would love that!

  17. John Baez says:

    Q: What is the one best thing everyone could do to slow down climate change?

    A: Actively seek correct information on climate change and your role in causing it, and take action accordingly.

    This answer may seem annoyingly vague. The problem is that no one action is best for everyone.

    Most of the global warming since 1950 is very likely to have been caused by the sudden spike in greenhouse gases: mostly carbon dioxide from burning fossil fuels, but also methane from cattle and other sources. By now carbon dioxide concentrations have shot up from 290 to 390 parts per million. If we continue ‘business as usual’ we may easily reach 1000 parts per million or more by the end of the 21st century. This will give the Earth’s climate a push whose rapidity and magnitude has no known precedent.

    To slow climate change, it is therefore crucial to reduce carbon emissions. However, carbon emissions are distributed very unevenly among the Earth’s population. For example, in 2007 the average human put 4.4 tons of carbon dioxide into the air through their use of fossil fuels and cement—but citizens of the EU put out 11.8 tons, and for the US the figure is even higher: 18.9 tons!

    So, what’s best to do depends a lot on who you are. If you’re a politician, maybe you can help eliminate some of the $300 billion yearly subsidies to the fossil fuel industry—subsidies that waste taxpayer money and encourage the burning of carbon. If you’re an average American, taking one fewer round-trip flight from New York to Los Angeles can save 3/4 of a ton of carbon dioxide. If you’re a subsistence farmer in Africa, you can turn some agricultural waste into charcoal and bury it: biochar is a promising low-tech way to sequester carbon. In many places, but not all, you can try to kick out politicians who fail to take climate change seriously. The best ways to do this vary from place to place.

    Thus, broad generalizations are difficult. But for everyone, the key step is to start actively seeking correct information on climate change and your role in causing it, and then take action accordingly.

    Some places to start include the Union of Concerned Scientists’ webpage What You Can Do about Global Warming, the National Academy of Sciences’s free online book Climate Stabilization Targets: Emissions, Concentrations, and Impacts over Decades to Millennia, and, especially good for businesspeople, the McKinsey & Company report Pathways to a Low-Carbon Economy.

    It is also wise to compute your carbon footprint and think of ways to reduce it.

  18. John Baez says:

    Eric wrote, speaking of the above graph:

    If you had shown me this chart 140,000 years ago during the previous spike, I would be similarly “scared”.

    Either scared, or excited, or something—it was certainly a big deal! It was the end of the second to last ‘ice age’, or technically, ‘glacial period’. Temperatures rose dramatically… but it all happened much more slowly than what we’re seeing now.

    This event is called the Eemian interglacial. It actually happened around 130,000 years ago.

    William T. replied:

    Actually, if you zoomed in the 140ky “spike” it would look nothing like the present spike – it was a slow and steady rise over several thousand years. Today’s spike is occurring over a century or two.

    Right.

    Let’s zoom in, as you suggest, and look carefully at the data. This data is the CO2 concentration in air bubbles in an ice core dug up from Vostok, Antarctica. You can download it from here. He’s one of the collaborators on this famous paper:

    • J. R. Petit, J. Jouzel, D. Raynaud, N. I. Barkov, J.-M. Barnola, I. Basile, M. Bender, J. Chappellaz, M. Davisk, G. Delaygue, M. Delmotte, V. M. Kotlyakov, M. Legrand, V. Y. Lipenkov, C. Lorius, L. Pépin, C. Ritz, E. Saltzmank and M. Stievenard, Climate and atmospheric history of the past 420,000 years from the Vostok ice core, Antarctica, Nature 399 (1999), 429-436.

    which is required reading for anyone interested in the historical temperature and CO2 record.

    Here’s a portion of the data showing the Eemian interglacial. The first number in each row here is the age of the air bubbles, in years B.P. (before present). The second is the parts per million of CO2:

    128300    274.1
    128399    287.1
    128652    286.8
    129007    282.7
    129411    264.1
    129755    263.4
    130106    257.9
    130167    259
    130992    264.6
    131661    245
    131789    240.4
    132067    228.9
    132818    223.5
    133334    224
    133366    220.3
    133636    210.6
    134205    208.9
    134362    203.7
    135003    204.6
    135172    200.4
    135271    198
    135683    198.1
    135976    201.8
    136099    200.7
    136359    202.5

    So, you’ll see that in roughly 3,500 years the CO2 went from about 200 ppm to about 290 ppm. That marked the end of a glacial period.

    [Note added later: it's closer to 7,000 years, not 3,500.]

    In the last 130 years, the CO2 has shot up from 290 ppm to 390 ppm.

    This illustrates what I mean about the suddenness of the current changes. It also illustrates another point: instead of going from a glacial period to an interglacial, we are going from an interglacial towards a new regime: a kind of climate the Earth hasn’t seen for many millions of years!

    Our children will live in this new world, but we have some choice over how much hotter this new world will be.

    • William T says:

      It’s actually more like 7,000 years – from 135ky to 128ky. Also, it wasn’t an “exponentially increasing” kind of curve as we’ve seen over the last 140 years. And since we know where the CO2 is coming from, we have a pretty good idea of how much further the curve will rise in the next 4-9 decades if things continue as they have been…

      No, I don’t think there is any comparison between now and 130,000 years ago.

      NOW is scary.

    • John Baez says:

      William T wrote:

      It’s actually more like 7,000 years – from 135ky to 128ky.

      Whoops! Since I’m a mathematician, you can never trust me when it comes to things like addition, multiplication, subtraction and division: I get bored and make mistakes. That’s why I like to do calculations here in a way that leaves a ‘data trail’, allowing everyone to check them.

      It would be fascinating to know how the Neanderthals adapted to the warmer weather during this 7000-year warming trend, and how they adapted to the next glacial, which began around 114,000 years ago and lasted until not very long ago. You can see a bit on Google Books here:

      • Nicholas J. Conard and Jürgen Richter, editors, Neanderthal Lifeways, Subsistence and Technology: One Hundred and Fifty Years of Neanderthal Study, Springer, Berlin, 2011.

      They hunted elephants and rhinos near the Rhine.

    • Eric says:

      So, you’ll see that in roughly 3,500 years the CO2 went from about 200 ppm to about 290 ppm. That marked the end of a glacial period.

      In the last 130 years, the CO2 has shot up from 290 ppm to 390 ppm.

      There are a couple of things I would need before I would take this data seriously.

      How do I know the data is accurate? So far the evidence is that you feel comfortable with it and some people have told you it is accurate. That is not science.

      How do we interpret the data? From my limited understanding, these numbers represent concentrations of elements in an ice core drilling. That is not the same thing as concentrations of elements in the atmosphere. How do the two relate? I doubt it would be a simple scalar multiple.

      Given that these are concentrations of elements in an ice core drilling, what is the mobility of these elements? It is reasonable to assume they do not diffuse at all over a period of 500,000 years? Any diffusion could easily through your estimates off by a few thousand years.

      John, you often say things like, “Sure, I can look this up on Wikipedia or read an article or two, but I’d prefer if someone could explain it here.” It is my turn to say the same.

      I am sympathetic to the goals here, but the evidence I am seeing is weak. Azimuth should do better. Put some error bars on your scare chart to help us understand how uncertain the measurements are. It is difficult for me to believe concentration based measurements spanning 500,000 year can be very accurate.

  19. John Baez says:

    Eric wrote, speaking of the above graph:

    How do I know your “scare chart” is accurate? How big are the error bars? How do they get data going back so many thousands of years with the accuracy implied by observing the data?

    You can click on the chart to see where the data came from. The different colored lines correspond to data obtained by different techniques. I don’t know the error bars—you’d have to poke around a bit.

    The most interesting part, I hope you’ll agree, is the dark blue line going back to 420,000 years ago. That data shows the carbon dioxide concentration in air bubbles from an ice core dug up in Vostok, Antarctica.

    Vostok Ice Core, National Oceanic and Atmospheric Administration.

    “In January 1998, the collaborative ice-drilling project between Russia, the United States, and France at the Russian Vostok station in East Antarctica yielded the deepest ice core ever recovered, reaching a depth of 3,623 m.” It goes back over 4 glacial cycles.

    I’m no expert on this stuff, so you can find out the answers to your questions almost as easily as I can. But I’ll say this: I feel perfectly happy about trusting this data. I understand in rough terms how you’d dig up an ice core, count the little layers that tell you how many years of snowfall there are, and how you’d measure the concentration of CO2 in the air bubbles. It’s a shockingly direct way of getting information compared to most of what people do in paleontology. I get a bit nervous about ‘temperature proxies’, where people use isotope concentrations to infer temperatures: it’s a widely used technique, but it involves assumptions that require expert judgement, and I’m not an expert. People use temperature proxies like oxygen-18 to infer temperatures from ice core data. However, this graph is not showing that: it’s showing CO2 concentrations, which you can measure directly and thus make me less nervous.

    Furthermore, the data are in general agreement with other ice cores during the time period that these other cores cover. It’s also in general agreement with other ways of dating the last 4 ice ages. The scientists I’ve read seem to think it’s good data.

    In short, I believe I’d have to be a fool not to take this data seriously.

    If you’re looking for things to worry about, you can worry that people are miscounting the tiny little layers that indicate years, you can worry that the air bubbles are getting contaminated in the process of digging up and slicing open the ice cores, and you can worry that the age of the air bubbles doesn’t match the age of the ice they’re found in. Needless to say, experts in this subject worry very hard about all these factors—and probably lots more that I don’t know about.

    I wouldn’t have thought about ice bubbles not matching the age of the ice they’re found in! But the people working on this did. For example, this website:

    Historical carbon dioxide record from the Vostok ice core, digital data.

    says:

    Because air bubbles do not close at the surface of the ice sheet but only near the firn-ice transition (that is, at ~90 m below the surface at Vostok), the air extracted from the ice is younger than the surrounding ice (Barnola et al. 1991). Using semiempirical models of densification applied to past Vostok climate conditions, Barnola et al. (1991) reported that the age difference between air and ice may be ~6000 years during the coldest periods instead of ~4000 years, as previously assumed. Ice samples were cut with a bandsaw in a cold room (at about -15°C) as close as possible to the center of the core in order to avoid surface contamination (Barnola et al. 1983). Gas extraction and measurements were performed with the “Grenoble analytical setup,” which involved crushing the ice sample (~40 g) under vacuum in a stainless steel container without melting it, expanding the gas released during the crushing in a pre-evacuated sampling loop, and analyzing the CO2 concentrations by gas chromatography (Barnola et al. 1983). The analytical system, except for the stainless steel container in which the ice was crushed, was calibrated for each ice sample measurement with a standard mixture of CO2 in nitrogen and oxygen. For further details on the experimental procedures and the dating of the successive ice layers at Vostok, see Barnola et al. (1987, 1991), Lorius et al. (1985), and Petit et al. (1999).

    If you have more questions you can track down these papers, or I can help you get them using my academic superpowers. I don’t think it’s a great use of my time to research this particular topic—the analysis of ice cores—except insofar as it’ll help me with my (or our) dream of understanding the relation between glacial cycles and Milankovitch cycles.

    If reading original papers is too boring, and you just want an overall view of the topic, this book is very good:

    • Richard B. Alley, The Two-Mile Time Machine: Ice Cores, Abrupt Climate Change, and Our Future, Princeton U. Press, 2002.

    How do I know you are not looking for data to support a preconceived notion?

    I’m afraid you either have to 1) trust me, or 2) not trust me and do your own research. The third alternative, not trusting me but not caring enough to do your own research, would be tragic.

    Is it possible someone could present a similar scare chart making the exact opposite argument?

    There are lots of ‘climate skeptic’ websites out there; in 10 minutes of research you can find all sorts of things, from the interesting to the purely idiotic. But I don’t know of any scientific studies of carbon dioxide concentration that give results significantly different from the chart I showed you.

    If you want an interesting objection to the conclusions we might draw from the above chart, try this: in the Vostok ice core, the CO2 concentrations often lag rather than lead the temperature (as measured by isotope proxies). So, some people argue that rising CO2 doesn’t actually make the temperatures higher, so we don’t need to worry about it. You may enjoy thinking about why this objection is not so devastating as it may sound.

    To me, what I’ve learned so far makes me feel quite certain that rapidly knocking the CO2 concentration up to levels not seen for millions of years is already affecting our climate, and will have much more serious effects in the decades to come.

    Even if I accept the chart as being accurate, how scared should I be?

    That’s a funny question, since fear is an emotional reaction. I don’t think I can say how you should feel.

    Personally, my initial reaction when I started studying this subject was not fear. I mainly wanted to break down and cry. After all, what’s starting to happen will affect others much more than me. I’ll be dead by the time things get really bad.

    After a year or so of moping around, I bucked up and got serious about trying to do something about all this. A key component of my philosophy is described here:

    While many groups are trying to prevent global warming before it gets worse, there is a powerful array of political and economic forces lined up against them. This makes it easy to fall into apathy. But this apathy is a serious mistake. It comes from a shallow analysis of the situation.

    Suppose, for the sake of argument, that the groups trying to prevent global warming, in fact fail. What next? Will the world come to an end? Will everyone die? Will all species go extinct? The answer is obviously no.

    If the world were certainly coming to an end, we’d be off the hook. We could say: “Nothing I do will really have any effect, so I might as well just relax and enjoy myself”.

    But we are not off the hook. Even if a disaster of some sort is certain, there are different degrees of disaster, and it’s our responsibility to minimize the disaster.

    • Frederik De Roo says:

      John wrote:

      in the Vostok ice core, the CO2 concentrations often lag rather than lead the temperature (as measured by isotope proxies). So, some people argue that rising CO2 doesn’t actually make the temperatures higher, so we don’t need to worry about it. You may enjoy thinking about why this objection is not so devastating as it may sound.

      In case someone has also been wondering about this, RealClimate offers an explanation, the bottomline of which:

      In other words, CO2 does not initiate the warmings [of the interglacials], but acts as an amplifier once they are underway.

      (italics added by me)

    • John Baez says:

      Frederik wrote:

      In case someone has also been wondering about this, RealClimate offers an explanation…

      Thanks. Their explanation is probably approximately right. But you’ll note how vague and hand-wavy it is— and that’s not because they’re trying to keep things nontechnical, it’s because there are a lot left ot understand here. They write:

      This is an issue that is often misunderstood in the public sphere and media, so it is worth spending some time to explain it and clarify it. At least three careful ice core studies have shown that CO2 starts to rise about 800 years (600-1000 years) after Antarctic temperature during glacial terminations. These terminations are pronounced warming periods that mark the ends of the ice ages that happen every 100,000 years or so.

      Does this prove that CO2 doesn’t cause global warming? The answer is no.

      The reason has to do with the fact that the warmings take about 5000 years to be complete. The lag is only 800 years. All that the lag shows is that CO2 did not cause the first 800 years of warming, out of the 5000 year trend. The other 4200 years of warming could in fact have been caused by CO2, as far as we can tell from this ice core data.

      The 4200 years of warming make up about 5/6 of the total warming. So CO2 could have caused the last 5/6 of the warming, but could not have caused the first 1/6 of the warming.

      It comes as no surprise that other factors besides CO2 affect climate. Changes in the amount of summer sunshine, due to changes in the Earth’s orbit around the sun that happen every 21,000 years, have long been known to affect the comings and goings of ice ages. Atlantic ocean circulation slowdowns are thought to warm Antarctica, also.

      From studying all the available data (not just ice cores), the probable sequence of events at a termination [of a glacial period] goes something like this. Some (currently unknown) process causes Antarctica and the surrounding ocean to warm. This process also causes CO2 to start rising, about 800 years later. Then CO2 further warms the whole planet, because of its heat-trapping properties. This leads to even further CO2 release. So CO2 during ice ages should be thought of as a “feedback”, much like the feedback that results from putting a microphone too near to a loudspeaker.

      Two questions stand out here:

      1) What is this “currently unknown” phenomenon that initiates the end of the glacial cycle? The most popular theory involves the Milankovitch cycles, which are explained here:

      Milankovitch cycles, Azimuth Library.

      These are various periodic changes in the Earth’s orbit, with periods of 26,000 years (precession), 41,000 years (changes in obliquity), 95,000 years, 125,000 years and 413,000 years (changes in eccentricity). If you plot these alongside the Earth’s temperature you can see patterns, but they’re quite rough: there’s a lot left to be explained! It seems likely that the Earth’s climate has very complicated internal dynamics—feedback mechanisms and other processes—that amplify and modulate whatever effect the Milankovitch cycles are having.

      2) “This process also causes CO2 to start rising, about 800 years later…” Why? The only effect I understand is that warmer oceans hold less CO2. But I think I’ve heard others mentioned… and I’ve never seen one worked out in the level of quantitative detail that I’d like. Part of this is surely my own fault: I haven’t taken the time to study this issue as much as I should. But my impression so far is that this feedback loop is poorly understood.

      It’s worth noting: climate skeptics who believe that high carbon dioxide levels are merely an effect of higher temperatures, and not a cause, have a responsibility to develop a convincing detailed quantitative theory for how this would work. This is not a court case where carbon dioxide is ‘innocent until proven guilty’. As it stands, it’s much easier to see, and much better understood, how high carbon dioxide levels cause higher temperatures.

  20. John Baez says:

    Staffan asked if the Azimuth Project might like to answer the Quora question

    Is global warming a hoax?

    Since this doesn’t seem like a very interesting question, I went ahead and answered it without a preliminary discussion here. We’ll tackle some more interesting questions soon.

  21. John Baez says:

    John wrote:

    So, you’ll see that in roughly 3,500 years the CO2 went from about 200 ppm to about 290 ppm. That marked the end of a glacial period.

    In the last 130 years, the CO2 has shot up from 290 ppm to 390 ppm.

    But don’t forget, William pointed out a math error here. It really took 7,000 years for that glacial period to end, not 3,500.

    How do we interpret the data? From my limited understanding, these numbers represent concentrations of elements in an ice core drilling. That is not the same thing as concentrations of elements in the atmosphere. How do the two relate? I doubt it would be a simple scalar multiple.

    We’re not talking about ‘elements’ here, we’re talking about CO2 in air bubbles trapped in ice.

    When snow piles up it traps air. So, ice contains air bubbles: samples of air from roughly the time the snow fell. This air contains nitrogen, oxygen, carbon dioxide and smaller amounts of other gases. If you take these air bubbles and work out the fraction of that air that’s carbon dioxide, you get the carbon dioxide concentration. There’s also a lot of water in the ice, and tiny amounts of other stuff, but we ignore all that.

    Given that these are concentrations of elements in an ice core drilling, what is the mobility of these elements? It is reasonable to assume they do not diffuse at all over a period of 500,000 years? Any diffusion could easily through your estimates off by a few thousand years.

    First of all, a few thousand years would not affect the conclusion I’m trying to draw.

    Second of all, if you look at the data you’ll see a thousand years of ice correspond to about 15 meters during this time period. So, for diffusion to throw off the calculations by, say, 2 thousand years, we’d need CO2 to diffuse through 30 meters of ice. That seems like a lot to me.

    How do I know the data is accurate? So far the evidence is that you feel comfortable with it and some people have told you it is accurate.

    I did more than that. I did what I could quickly and easily do. I explained how the measurement is done. I pointed you to a really great book that explains the subject in more detail, including the history of the subject:

    • Richard B. Alley, The Two-Mile Time Machine: Ice Cores, Abrupt Climate Change, and Our Future, Princeton U. Press, 2002.

    I described the biggest known source of error, which would throw the dates off by 5000 or 6000 years if not taken into account.

    I mentioned that this ice core agrees substantially with other ice cores during the time they overlap. (This one goes back further than any other).

    I did not show you error bars, which I regret, because I have not found error bars. Since most of the errors are likely to be systematic in nature, it’s not clear how to generate useful error bars! But I guess we could compare CO2 concentrations measured in different ice cores. Should we try that? Do you want to help?

    That is not science.

    Actually it is. As you know, I’m not a climate scientist, and especially not an expert in ice cores. It’s completely normal practice for scientists to use data taken from other scientists with other areas of expertise without first becoming a complete expert in those other areas. Science would be impossible without this. The basic strategy is to trust unless there seems to be a good reason not to.

    Of course, one good reason includes ‘just because I feel like it’. If you feel like poking into something and questioning it, you go ahead and do that.

    But personally, I’m worried about other sources of uncertainty much more than I’m worried about this ice core. There are lots of other important things, like predicting the climate or figuring out how we could stop global warming, that seem a infinitely more difficult. I only have a limited amount of time each day and I need to focus on getting the most bang for the buck.

    So, if you raise an interesting reason for me to doubt this data, then we can try look into it further. But you haven’t yet.

    Ultimately I hope we’ll have enough experts reading this blog so that you could ask a question about ice cores, say, and get an answer from an expert. Maybe if we wait one will show up. But for me to research this question is at best slightly faster than for you to research it—slightly faster, maybe, because I’ve read about this stuff a bit more.

    By the way, the goal of the Azimuth Project is not to convince doubters that global warming is a serious business. There are lots of people already working on that, and so far it’s mainly just a big time sink. The Azimuth Project is more about taking people who want to help and giving them some ways to help. This is why I’m perfectly willing to say “not convinced? Okay, so you’re not convinced.”

    • John Baez says:

      Here’s a bit more on this stuff. I shouldn’t be spending my time researching this, but thanks to Eric needling me I couldn’t help myself:

      • A. Indermühle, T. F. Stocker, F. Joos, H. Fischer, H. J. Smith, M. Wahlen, B. Deck, D. Mastroianni, J. Tschumi, T. Blunier, R. Meyer & B. Stauffer, Holocene carbon-cycle dynamics based on CO2 trapped in ice at Taylor Dome, Antarctica Nature 398, 121-125.

      This is about a different ice core, one that only goes back 11,000 years. This is enough to catch the end of the last glacial cycle, but not the one before that, which is the one Eric was asking about.

      They explain some ways the CO2 concentration can get thrown off—ways I hadn’t known about:

      The reconstruction of atmospheric CO2 concentration from ice cores is not a straightforward procedure owing to the following difficulties. High-resolution measurements of CO CO2, and the comparison of CO2 records from different ice cores, have shown that the atmospheric CO2 signal can be masked by CO2 production in the ice matrix; such in situ production is most likely due to chemical reactions between impurities, collectively referred to as natural artefacts. The physics and chemistry of these processes, documented in ice cores from Greenland [14-16], are little known, but two possible candidates are being investigated. (1) Acid±carbonate reactions [14,16,17] and (2) oxidation of organic matter by H2O2 (ref. 18). The probability of a reaction depends on the concentration of the impurities and their location in the ice (for example, at grain boundaries or associated with dust particles), which are not known in detail for either Greenland or Antarctic cores. But it has been shown that the concentrations of the impurities are one order of magnitude smaller in ice cores from Antarctica than in those from Greenland, so that the probability of natural artefacts is smaller in Antarctic records [14,18,19]. Detailed measurements on a Greenland core (GRIP) have shown an in situ CO2-production potential (by an acid±carbonate reaction) of up to 3,000 p.p.m.v., but a CO2 surplus of only 30 p.p.m.v. has been observed [18]. Thus, an existing CO2-production potential does not necessarily mean that a natural artefact occurs. At present, the most promising test to detect such natural artefacts is to perform detailed measurements across a few annual layers. If the measured CO2 concentration represents the atmospheric composition, the variation between adjacent samples should be similar to the analytical uncertainty. If CO2 is produced by chemical reactions, a larger scatter of the data points is likely.

      Fractionation of CO2 between bubbles and clathrates may occur in the clathrate-formation zone of the ice, whose depth depends on the local temperature [20]. If the extraction efficiency is below 100%, which is the case with our device, a depletion of CO2 in the extracted air could occur. However, calculations reveal that ice of the Holocene period from Taylor Dome is clearly above the clathrate zone, and so this problem is not relevant.

      This paper has a graph with error bars, which is nice, though as I mentioned earlier these error bars are of somewhat limited usefulness. The big graph in the paper shows the mean of five to six samples from Taylor Dome ice core measured in Bern, the mean of three to six samples measured in San Diego, some data from Byrd Station ice core, and 1-σ error bars—presumably from all this data?

      The Byrd Station data is rather scruffy-looking compared to the Taylor Dome data, and the authors suggest some reasons why.

      The most reliable-looking feature of the graph is a fairly smooth increase in CO2 concentrations from 260 ppm back in 8000 BP (before present), going up to 290 ppm fairly recently. Of course, from the industrial revolution to now it’s shot up from 290 to about 390. As the authors note:

      The rate of change of atmospheric CO2 concentration over the Holocene is two orders of magnitude smaller than the anthropogenic
      CO2 increase since industrialization.

      Of course the Holocene starts after the end of the last glacial cycle; I think Eric was wondering about rate of CO2 increase during the end of glacial cycles, so this is only indirectly relevant—but it’s not nothing.

      In case it’s not obvious, let me emphasize that I’m not an expert on this stuff, and I doubt I’ll ever become one. This is just the first paper I happened to bump into that had a nice discussion of possible sources of error in CO2 concentrations as measured in ice cores.

    • Eric says:

      When snow piles up it traps air. So, ice contains air bubbles: samples of air from roughly the time the snow fell.

      I’m curious how mobile this air is. If you were to insert a high-pressure tube into the ground and start pumping CO2 into it, how deep could it penetrate? The ability for CO2 to diffuse is one mechanism that could throw off the older sample data. It is not difficult for me to imagine C02 diffusing 150 meters, much less 15 meters over the course of 423,000 years.

      The basic strategy is to trust unless there seems to be a good reason not to.

      That might work with mathematics, but with empirical sciences highly dependent on data gathering, I take the exact opposite approach.

      Never trust unless there seems to be a good reason to.

      Especially if someone seems to have an agenda, I am even less willing to trust the data.

      By the way, the goal of the Azimuth Project is not to convince doubters that global warming is a serious business.

      I never said it was. I was here from the beginning. One of the goals of Azimuth is to provide objective data that goes beyond the hype of either side of the debate. This data from your scare chart is meant to scare people. It made you want to “break down and cry”. I think we should at least try to present this data in as clear and objective way as possible. I’m happy to help. I’m not looking to be convinced either way. I’m merely trying to become comfortable with the scare data being presented to me.

      Let me attempt to clarify what I’m after. It doesn’t need to be you, but hopefully some expert reading can help.

      I’m pretty comfortable with the concept of an ice core drilling. I’m pretty comfortable with the science used to analyze the composition of the ice core. The Nature article stated that the CO2 measurement error is less than 1%. I do not doubt that.

      So there you have a 3,310 meter ice core with fairly precise measurements of CO2 concentration along the core.

      There are at least two transformations that must take place to map this data to the data we’re interested in, i.e. atmospheric CO2 as a function of time.

      First, we need to map depth to time. This is prone to errors. I do not know how large the errors could be, but they could very well be quite significant. How significant? That is one question we could answer by trolling the references and summarizing on an Azimuth page. You can be sure if I find out, I’ll add it.

      The second transformation is from concentration of CO2 in the ice core to CO2 concentration in the atmosphere. Were there any sources of photosynthesis anywhere near the vicinity of the core any time during the last 423,000 years? I could imagine that might significantly impact the CO2 concentrations found in the core.

      Did any of the ice ever melt during the past 423,000 years?

      Once again, how easily can the CO2 diffuse through the ice? Not at all? A little? If even just a little, this could add up over the course of 423,000 years.

      Does the absorption of CO2 into ice depend in any way on the concentrations of other molecules in the air at the time?

      Each mapping:

      Depth -> Time

      Core Concentration -> Atmosphere Concentration

      is model dependent. What are the models? How robust/accurate are the models? Is it reasonable to expect errors of the order 200% over the course of 423,000 years?

      How are the models/measurements calibrated? What is the truth by which the model is estimated?

      How sensitive is the data/model to the insolation? In my experience playing with insolation, it is pretty clear to me that some huge approximations are made and it is easy to imagine huge errors accumulating over 423,000 years.

      One danger for you John, especially considering you’re not a climate scientist, is to be “fooled” by someone with an agenda presenting biased data to you in order to further their political goals. You, of anyone, should be especially skeptical of any data presented to you.

      • Florifulgurator says:

        (Mad scientists being so mad to go as far as Antarctica to fake ice core data in order to further their hidden agenda… How mad is that?)

        Here’s what convinces me on first sight of their scare graph: It reconstructs a quasi-periodic stochastic process. If the data were just noise, that would be an extremely improbable artefact.

        And besides, the graph is peer reviewed, in line with other things known about paleoclimate, and there are several of them. Cf. e.g. http://en.wikipedia.org/wiki/Ice_core

        • Eric says:

          Straw man arguments do not improve the quality of discussion. I never said they fake the ice core data. Quite the opposite. I said I do not doubt the ice core data itself. There is 3,310 meters of ice core with CO2 concentration levels measured accurately to within 1%. The question and the source of any artistic interpretation is in how that data is transformed.

          An expedition to Antarctica to drill a 3,310 meter ice core is expensive. Who funded it? I doubt the sponsor is 100% objective. They had a reason to fund the expedition and may have a vested interest in seeing some particular outcome. There are probably at least 10 decent inequivalent ways to map depth to time. Similarly, there are probably at least 10 decent inequivalent ways to map core concentrations to atmospheric concentrations. Therefore, there are at least 100 decent ways this data could have been presented. Why did they present just one? Why this particular choice? How hard would it have been to present alternatives? How do we know they did not present 100 charts to the sponsor and decide to choose the one with the scariest scare charts?

          The fact the charts demonstrate a quasi-periodic stochastic process convinces me even less of the conclusions because I have no reason to expect nature follow a quasi-periodic stochastic process. Why should climate conform to such simple models especially over such time scales?

          Nature is a for-profit publication with an agenda: sell magazines. I am not impressed by the fact an article has been peer reviewed. Considering the importance of the subject, the authors could have done more to demonstrate the objectivity of the results presented. One thing that could have helped was to demonstrate the robustness of the conclusions to the hundreds of possible ways of presenting/transforming the data.

          Starting with the raw data, it would be interesting to test the robustness ourselves. This could be an interesting Azimuth project. To be honest, I do not expect any smoking guns. The results are likely robust to the models used, but seeing that robustness explicitly would help give me comfort.

        • Frederik De Roo says:

          Here’s an article that discusses one of Eric’s remarks:

          • J. Ahn et al, CO2 diffusion in polar ice: observations from naturally formed CO2 spikes in the Siple Dome (Antarctica) ice core Journal of Glaciology 54 (2008).

          One common assumption in interpreting ice-core CO2 records is that diffusion in the ice does not affect the concentration profile. However, this assumption remains untested because the extremely small CO2 diffusion coefficient in ice has not been accurately determined in the laboratory. In this study we take advantage of high levels of CO2 associated with refrozen layers in an ice core from Siple Dome, Antarctica, to study CO2 diffusion rates. We use noble gases (Xe/Ar and Kr/Ar), electrical conductivity and Ca2+ ion concentrations to show that substantial CO2 diffusion may occur in ice on timescales of thousands of years. We estimate the permeation coefficient for CO2 in ice is ∼4 x 10-21 mol m-1 s-1 Pa-1 at -23°C in the top 287m (corresponding to 2.74 kyr). Smoothing of the CO2 record by diffusion at this depth/age is one or two orders of magnitude smaller than the smoothing in the firn. However, simulations for depths of ∼930-950 m (∼60-70 kyr) indicate that smoothing of the CO2 record by diffusion in deep ice is comparable to smoothing in the firn. Other types of diffusion (e.g. via liquid in ice grain boundaries or veins) may also be important but their influence has not been quantified.

          Eric, I don’t agree with the following comment of yours:

          They had a reason to fund the expedition and may have a vested interest in seeing some particular outcome.

          In this case, you shouldn’t trust any new particle that would be detected at LHC. It’s an expensive and complicated machine and those who built it want to detect something, which makes every detection suspect.

        • Eric says:

          Thanks Frederik! That is a very interesting paper.

      • John Baez says:

        Eric wrote:

        I’m curious how mobile this air is.

        I think Frederik gave you a good answer to that—unless of course you believe the paper he was quoting was motivated by a political agenda and can’t be trusted, etc.

        You’ll note the paper he quotes, the one by J. Ahn et al, says:

        Smoothing of the CO2 record by diffusion at this depth/age [the top 287m, corresponding to 2.74 kyr] is one or two orders of magnitude smaller than the smoothing in the firn. However, simulations for depths of ∼930-950 m (∼60-70 kyr) indicate that smoothing of the CO2 record by diffusion in deep ice is comparable to smoothing in the firn.

        We already came close to noticing the problem of ‘smoothing in the firn’, but you might not have noticed that. Firn is a kind of partially compacted snow—denser than névé but not yet as dense as ice. Sorry for all the jargon, but you know how it goes: people who study snow are going to have lots of words for it. In an earlier comment, I quoted J.-M. Barnola, D. Raynaud, C. Lorius as writing:

        Because air bubbles do not close at the surface of the ice sheet but only near the firn-ice transition (that is, at ~90 m below the surface at Vostok), the air extracted from the ice is younger than the surrounding ice (Barnola et al. 1991). Using semiempirical models of densification applied to past Vostok climate conditions, Barnola et al. (1991) reported that the age difference between air and ice may be ~6000 years during the coldest periods instead of ~4000 years, as previously assumed.

        The point here is that until the snow gets squashed down to ice about 90 meters below the surface, the air bubbles don’t close. They’re saying that this makes air rise to levels higher than the snow it came from. That makes sense.

        But also, of course, there will be some tendency for air coming from different layers of snow to mix until the air bubbles get sealed off. This would tend to ‘smooth out’ the effect of rapid chances in CO2. I presume this is what ‘smoothing in the firn’ means.

        So, if you want to argue that rapid changes in CO2 concentration have been ‘smoothed out’ in the ice core record, thus seeming slower than they really were, here’s one way to make that argument.

        Unfortunately, J. Ahn et al argue that this ‘smoothing’ effect should only extend for less than a century. See Figure 5 in their paper. So, I don’t think a sudden rise in CO2 like we’re seeing now could have gotten ‘smoothed out’ to seem like it took 7000 years—the amount of time the Vostok ice core says it took for the Eemian interglacial to start.

        So, I don’t feel drastically changed in any of my opinions thus far, though you have managed to make me learn some stuff.

  22. Phil Henshaw says:

    Here’s a cool Ice core CO2 figure I did years ago, http://www.synapse9.com/iceco2-3.gif discussed briefly at http://www.synapse9.com/drpage.htm#iceco2.

    The relevant detail for the data reliability question was that I found the fluctuations in CO2 read for the ice core to be so very remarkably smooth that I could easily pick up the discontinuities of what seemed to be occasional instrument calibration errors, and correct them!

    • John Baez says:

      Nice! I guess we can wonder how much of this ‘remarkable smoothness’ is caused by smoothing in the firn and also diffusion of CO2 further down.

      • Phil Henshaw says:

        I guess we’d have no easy way to tell which of the several sources of diffusion in the ice have what degree of effect. So on a first pass I just fall back on the more important question, does it really matter? For measures for which you can’t quantify any relation to any other anyway, information consistency is what’s most important for forensic research, to then correlate events rather than measures.

        If a measure is at least consistent you can then take its changes as being changes of something other than your method of observation. It’s also good to explore the whole variety of natural processes that might bias the measure at different times, especially when trying to confirm what actual physical process you are observing changes in, of course. Still, first studying the system without attempting to define your measures as variables for equations saves lots of time and effort looking for relationships that can’t really be quantified anyway. Environmental systems are so complex and sit still for only such short periods, you rarely have a definable system within which to quantify the relation between variables anyway.

        So for correlating events, tie things observed in other measures taken elsewhere to a common system of change, what a consistent measure can still do in identify coincident changes in direction or acceleration, or in growth rates, or changes in the character of fluctuation, etc. Lots of times like you need to recognize connections between fluctuation in one thing with movement in another. No matter how complex, all connected processes are connected by their accumulative energy flows.

        It’s like confirming that a person is in motion my noting the swinging of their arms. Natural systems may be most easily and unequivocally identified by how their network of relationships emerges as a whole by a growth process involving all their parts, but that simple sign of systemicity isn’t always what your data shows you.

        For that Ice-core CO2 data, one might just start by asking what is producing that remarkably regular 2 to 4,000 year fluctuation in atmospheric CO2. That could be the small scale process that is driving the other scales of change (being variably accumulative or dissipative). It might only be like the ripples on the waves on the swells of successively larger scale systems all representing different things. Sometimes it’s the tail that wags the dog, or hard to tell.

  23. John Baez says:

    Eric wrote:

    This data from your scare chart is meant to scare people.

    Let’s be clear here. The chart here

    is from Global Warming Art, which has an agenda described here. But if you click on it you’ll get to the sources, which are scientific papers, and right now we’re talking about the dark blue curve, which comes from thisNature paper. And I wouldn’t say this paper was written to scare people. I think it was written to impress the scientific community with a detailed and careful analysis of the deepest ice core ever obtained.

    It made you want to “break down and cry”.

    No, I didn’t say that. I said:

    Personally, my initial reaction when I started studying this subject was not fear. I mainly wanted to break down and cry.

    This was the cumulative effect of a year of learning about climate change from many sources. I’m not so easily persuaded that a single chart or a single paper will have a dramatic effect on my beliefs or emotions.

    In particular, I believe this chart is about right because it meshes with lots of other things I’ve learned:

    There are lots of reasons that I believe there were glacial cycles occurring at times consistent with those shown in this chart. There are lots of reasons I believe temperature is correlated to atmospheric CO2 concentration, so it makes sense that the CO2 concentration is lower during the glacials and higher during the interglacials. It makes sense that the CO2 concentration right before the industrial revolution would be about the same as during previous interglacials. And there are lots of reasons to believe it’s shot up since then.

    In short, I see nothing strange or unbelievable about this chart. And I can’t help asking: is there something about it that seems strange to you? If there is, we should focus on that.

    An expedition to Antarctica to drill a 3,310 meter ice core is expensive. Who funded it? I doubt the sponsor is 100% objective. They had a reason to fund the expedition and may have a vested interest in seeing some particular outcome.

    Sigh… Vostok began life as a Soviet station and they started drilling ice cores back in the 1970s. The one we’re talking about is the deepest of several; it was drilled in collaboration with the French. It’s famous in part because they were sort of pressured to stop by the Scientific Committee on Antarctic Research before they hit Lake Vostok, an enormous lake of liquid water way down there. A bunch of scientists didn’t want them to contaminate this lake with oil from the drilling process, or bacteria that come from the Earth’s surface. There could be interesting life forms down there.

    This is just one of many expeditions to drill ice cores; it looks like about 19 major ones from Greenland and 12 from Antarctica. The Vostok one is famous because for a long time it was the one that went back the farthest in time: about 420,000 years. I thought it was still the record-holder but now I see that EPICA goes back 800,000 years.

    I think your doubts may diminish slightly if you look at this comparison between deuterium concentrations from Vostok and EPICA:

    (Click to enlarge.)

    I know we’re not talking about deuterium; we’re talking about CO2. So, someone will have to find a comparison of their CO2 measurements. But you’ll see that while depth is not a purely linear function of age, you can use the wiggles in the graphs to match up the two graphs.

    Personally the problem of determining the exact dates when CO2 levels changed has very little to do with my belief that we’re entering a phase of high CO2 concentrations, unprecedented in at least the last 400,000 years and probably longer. That’s what matters most for global warming!

    On the other hand, determining the dates is important if we’re trying to see whether the Milankovitch cycles cause the glacial cycles.

  24. John Baez says:

    Here’s Figure 5 in Ahn et al‘s paper:

    (Click to enlarge.)

    The paper explains what’s going on here, but the basic idea is that they’re trying to figure out how a 10-year spike in carbon dioxide would get ‘smoothed out’ in an the ice core thanks to diffusion and other mechanisms.

    The basic upshot is that they’re claiming this ‘smoothing’ only smears out the CO2 concentration record by a century or less. If so, there’s no way a rapid spike in carbon dioxide like we’re seeing now could get smeared out to look like the 7000-year rise we saw at the end of the second-to-last ice age here.

    • Eric says:

      I like that Figure as well. It is not so much the smearing out in time that is noticeable, but the reduction in magnitude.

      It would be interesting to run the diffusion backward in time. The deeper/further you go, the spikier the data will become. This just might make comparisons to shallower/more recent data less striking.

      Very interesting.

    • John Baez says:

      Eric wrote:

      It is not so much the smearing out in time that is noticeable, but the reduction in magnitude.

      That’s because they’re smearing out a spike that’s 10 years wide. The effect would become less with a spike that lasted longer.

      Experts like you will know that I’m talking about ‘convolution with a Gaussian’ and how it acts as a ‘low-pass filter’. That means that the diffusion of CO2 in ice cores will dramatically blur fine details in our record of ancient CO2 concentrations… but have little effect on the record of slower changes.

      Nonexperts may prefer this analogy: if you need glasses to see, everything will look blurry when you take them off. So, you’ll have trouble reading the fine print on your telephone bill… but you can probably still read a big sign.

      To get a rough idea of how this works, let’s replace the Gaussian bumps shown above by rectangles. Suppose the effect of smearing is to take an instantaneous spike of CO2 concentration and flatten it out to a rectangle that lasts 100 years.

      Then a 1-year spike of CO2 concentration will be smeared out to an approximately rectangular bump that lasts 101 years… so the height of this bump will be roughly 1/101 times as tall as the original spike. The approximation here is quite good: the bump won’t be exactly a rectangle, but it will be close.

      A 10-year spike as shown above will be smeared out to an approximately rectangular bump that lasts 110 years… so the height of this bump would be about 1/11 as tall as the original spike. The approximation here is still pretty good.

      A 100-year spike will roughly be smeared out to a bump that lasts 200 years… so the height of this bump is 1/2 as tall, on average, as the original spike. The phrase ‘on average’ is important here. If you work out the details, you’ll see this particular bump looks more like a triangle than a rectangle. It takes 100 years to ramp up, and 100 years to ramp down.

      A 1000-year spike will be be smeared out to an approximately rectangular bump that lasts 1100 years… so the height of this bump is 10/11 as tall, on average, as the original spike. In fact the bump will be the exact same height as the original spike, except for the first 50 years and the last 50 years. So now it looks almost like a rectangle again.

      A 10,000-year spike will be be smeared out to an approximately rectangle bump that lasts approximately 10,100 years… so the height of this bump is 100/101 as tall, on average, as the original spike. Yet again, this bump is the exact same height as the original spike, except for the first 50 years and the last 50 years.

      So, you can see that this kind of ‘100-year smearing’ effect will really screw up our understanding of climate changes that happen more quickly than 100 years, but not our understanding of changes that happen much more slowly.

      And so, when the Vostok ice core says the last interglacial (the Eemian) took 7000 years to come on, it doesn’t seem likely that this is far off. It could easily be 200 or even 500 years off. Heck, let’s say it’s 1000 years off! If so, the second bump to the right here, the one Eric was curious about, may have taken as little as 6000 years to rise to its peak:

      But that’s still a lot slower than the rise in CO2 levels we’re seeing now—the vertical line at the far right end of the graph. That rise, from 290 to 390 parts per million, took only about 125 years. And that vertical line is going keep shooting up until we do something about it.

      And so I repeat: part of the problem is that we’re taking the Earth’s CO2 levels out of the range they’ve been in for hundreds of thousands of years, and we’re doing it very fast compared to natural processes.

  25. John Baez says:

    Since we’re having fun comparing the currently skyrocketing CO2 levels to the beginning of the last interglacial, the Eemian, back around 130,000 years ago, I think some of you will enjoy this blog post:

    • Stuart Staniford, Living in the Eemian, The Oil Drum, 20 February 2006.

    He compares the Eemian to the present interglacial, which is called the Holocene. He shows a graph of temperatures based on deuterium proxies taken from the Vostok ice core:

    As usual, paleontologists like graphs where the past is on the right and the present is on the left. That used to freak me out.

    Also, just for fun, he slides the Eemian over so it overlaps with the Holocene, so we can compare them:

    (Click to enlarge.)

    This lets us see that they’re pretty similar… so far. However, you can see that the Holocene got off to a warm early start around 11,000 years ago. Then temperatures took a brief nosedive: that’s the Younger Dryas episode. Also, you can see that later on, the Holocene was a bit cooler than the Eemian.

    There are lots of things to wonder about here.

  26. Eric says:

    I’m finding this to be a bit frustrating.

    The Vostok data here has some minor errors:

    1. At 2666.7 m
    2. At 2674.6 m
    3. At 3057.7 m
    3. At 3072.5 m

    At these points, there is a change in depth and CO2 concentration levels, but no change in age.

    At 3889.45 m, there is no change in depth, no change in age, but a change in CO2 levels. How can that be?

    These kinds of errors do not lend to a great deal of confidence.

    The Vostok data starts at a depth of 149.1 m and age 5679 years. Splicing this data with more recent data to produce those scare charts should be done with great care. Is there a reference that explains/justifies the splicing?

    I’m interested in modeling these glacial periods taking into consideration the diffusion of CO2 going back as far back as possible, e.g. 420,000 years. The Ahn data goes back just 80,000 years or so and states that the diffusion can become more significant at greater depths.

    I have no doubt CO2 emissions have increased throughout the industrial revolution, but I want some stronger evidence of the magnitude compared to prior cycles than what I’ve seen so far.

  27. Phil Henshaw says:

    Eric,
    The things you find needing explanation may or may be errors, but they wouldn’t seem to influence the interpretation of the data. The continuity of the whole data set is remarkably strong here, and it’s that overall shape that counts. I did the graph, showing the ages of the air and ice samples changing very smoothly with the depth of the ice, though not a straight line. The layers per year seem consistently thinner the deeper you go.

    So you have a very clear and accurate way to measure the ages of the samples from the shape of the smooth curves. Here the most recent sample was about 150 m deep and from ice of 5600 years ago.

    There’s simple rule you might consider, that in economics you always want to do things to make nature fit the image of what you want from it, but in science you always want your image to fit the shapes of nature, just the reverse. Are you taking that approach?

  28. Eric says:

    Hi Phil,

    Thanks for your comments. I really like what you had to say earlier

    So on a first pass I just fall back on the more important question, does it really matter? For measures for which you can’t quantify any relation to any other anyway, information consistency is what’s most important for forensic research, to then correlate events rather than measures.

    In terms of trends and correlations, I have no quibbles. The Vostok data is very nice. The cycles are clear and pronounced and can be correlated to events present in other data sets. And whether the “measures” are accurate or not seems besides the point.

    Unless… that is your point. I’m trying to get a handle on the magnitudes because that is one of John’s primary reasons for taking the scare chart seriously. As you note (and I noted), the Vostok data begins 5600 years ago and goes back 420,000 years. The scare data is from the most recent 200 years or so. Putting that scare chart up to scare people requires splicing the Vostok data with more recent data. I’m not completely convinced the splicing is done appropriately. The way it is done could conceivably be artificially amplifying the human impact. The significance of the industrial revolution is something I’d like to get a handle on.

    There’s simple rule you might consider, that in economics you always want to do things to make nature fit the image of what you want from it, but in science you always want your image to fit the shapes of nature, just the reverse. Are you taking that approach?

    I’m not 100% sure what you are asking, but I can say that I try to be objective to the extreme when it comes to interpreting data. I’m aware that economists can and routinely do bend the data to fit what they want to see. I want the data to as objectively as possible reflect nature.

    The one thing the data DOES demonstrate clearly is the presence of cycles. That, to me, is more interesting than the scare chart. Glacial cycles happen and will continue to happen regardless of what humans do. Perhaps carbon emissions do accelerate the cycle, but they do not create it. The cycle happens with or without us. That is the thing that seems the most concerning. Even more so than recent CO2 emissions. Modern civilization just isn’t prepared for the coming ice age. Instead of trying to slow climate change, maybe we should be focusing on adapting to the inevitable.

    PS: One thing I’ve been frustrated about when it comes to monetary policy for the 10 years or so prior to the latest financial crisis, a period that used to be called the “Great Moderation” (you don’t hear that term used much anymore), was the extreme fear of recessions. Recessions are an important part of a healthy business cycle. They eliminate the weakest elements and make way for the strongest. In a way, it is economic Darwinism. When the Fed lowered interest rates whenever the smallest sign of a recession appeared, it seemed that they had done away with the business cycle. But all it did was create huge imbalances. Institutions that should have failed were instead bailed out either directly or subsidized indirectly through low rates.

    Maybe glacial cycles are the same. Maybe glacial cycles are good for the health of the earth. They weed out the weakest elements making room for the stronger. It takes a tremendous ego for humans to think they can or should try to do something about this. The next glacial cycle will similarly weed out the weakest elements, but maybe this time those weakest elements are us.

    • Phil Henshaw says:

      Well, I notice that you repeat a characterization of the current atmospheric measurements as “the scare data”, which is not how scientists normally approach it. They usually name where the data came from so those interested can inquire about the measurement process and its built-in uncertainties.. but, you know, that’s just a quibble.

      You’re concerned that the magnitude may have been fudged by a politically motivated world of scientists, though. In that case there’s nothing at all that the data tells us, and there’s no use discussing the question really. Just as you need the physical process of measurement to have limited uncertainties you also need the people handling it to be faithfully keeping their own errors in using the data within reliable limits.

      I personally don’t believe the world community of scientists would purposefully misrepresent the data. So my reading of it has always been very simple, and doesn’t rely on the magnitude. The rate of change in CO2 today is on an entirely different time scale than any of the historic changes, far faster than any other natural cause I know of other than volcanic eruptions. So if you believe the data at all, it seems to say our economy is going off like a volcano. That reasoning seems quite sound, and quite scientific to me. Do you see any problem with it?

      As to “creative destruction” cycles of both nature and the economy I certainly agree that they can be “healthy” in pushing a system to rejuvenate itself. If waves of destruction destroy enough of a system so it can’t rejuvenate, as for the collapse of the Dinosaurs, say, you still have interesting outcomes, like the many communities of birds we now have, but that isn’t good for the Dinosaurs.

      So the problem with the “creative destruction” cycles of the economy is that they are getting bigger, and bigger, threatening the whole world economy. For example, in addition to climate change we now have the next bigger, more urgent and threatening global environmental catastrophe. Some call it “peak everything” or “the big crunch”, others the more scientific “global demand exceeding supply”. That’s what is causing both the escalating prices of food and fuel resources, and also the inability of the markets to recover from shocks, like severe weather events or speculative manipulation. I do research and writing on that too.

      http://www.synapse9.com/pub/ASustInvestMoment-PH.pdf

      Unlike in the past, resource prices now fall back from their peaks by the economy shedding demand as sectors fail, not by creating new sources of supply as once was the pattern. The economy is acting a lot like how a tree or plant in a drought acts, protecting its core by shedding old or weak leaves and limbs. That it is beginning to shed us now (the developed world’s middle class) is a problem. We have much too high overhead to produce goods and services as cheaply as the poor communities we gave our technology and designs to.

      It’s a direct effect of our maximizing financial investment earnings. The greater irony is it’s importantly everyone’s retirement funds actively pushing that dislocation as fast as it can go… ! I saw this happening, and this scale of increasing scales of problems as quite inevitable for our economy, a long time ago. That’s why I’ve carefully studied it.

      • Eric says:

        Hi Phil. Thanks again for your comments.

        The rate of change in CO2 today is on an entirely different time scale than any of the historic changes, far faster than any other natural cause I know of other than volcanic eruptions. So if you believe the data at all, it seems to say our economy is going off like a volcano. That reasoning seems quite sound, and quite scientific to me. Do you see any problem with it?

        I wouldn’t say I have a “problem” with it, but I have questions about it. When you compare time scales of changes today to those observed in the ice cores, the rate dc/dt is obviously sensitive to the magnitude c. It is also sensitive to diffusion. If diffusion is significant for the deeper readings corresponding to earlier glacial cycles, then this would make the earlier cycles appear slower and less pronounced. John made some good arguments that make me less concerned about this possibility, but his analysis was restricted to the most recent 80,000 years. Vostok goes back 420,000 years. The diffusion could be more pronounced for the deeper/earlier cycles. I would still like to do some work on this.

        So the problem with the “creative destruction” cycles of the economy is that they are getting bigger, and bigger, threatening the whole world economy.

        I mentioned the “Great Moderation”, but didn’t give the punchline. I like to make the analogy to forest fires. See, for example:

        Natural History of Fire & Flood Cycles

        While reading it, I like to replace:

        – “forest fire” with “recession”
        – “fire cycle” with “business cycle”
        – “ecosystem” with “economy”
        – “fire suppression” with “stimulus”
        – Etc

        But I suppose for this discussion, we do not need to make those replacements because the ideas apply directly.

        Basically, when you get very good at putting out forest fires, this increases the frequency of enormous forest fires. Forest fires naturally clean up the flammable brush, but when you race to put out every fire, the unintended consequence is that you get forests overrun with flammable brush so that when a fire does get out of hand, it turns into an extreme forest fire.

        The same thing goes with economies. When you do not let natural recessions occur, i.e. when the Fed stimulates the economic at the first sign of a downturn, you get a bunch of businesses and sectors of the economy that survive when they should have been burned. Thus, when an economic situation does get out of control, the consequences are much worse.

        • Phil Henshaw says:

          Eric, Really, you seem to construct the natural world in your mind as if it were a fabrication of reasons, any of which might change all the others instantaneously. The physical world is not like that.

          Science is based on finding special questions that can be answered with very high confidence, and building on them like steel columns and girders build on a building foundation buried in the earth. You keep saying, or so it seems to me, “What if we find the building has no foundation?”, and that’s after it’s been built, occupied and lived in for generations. It’s perfectly fine to think that way as a playwright or movie producer, but just shows you’re not a structural engineer, and not trying to learn how to be one.

        • Thomas Fischbacher says:

          Concerning this concept of “hyper-skepticism”, I wonder what one should then e.g. think of the “hyper-skeptics” that do not take the evidence in favour of the first law of thermodynamics as conclusive. After all, it’s all just evidence and no one ever managed to prove energy conservation.

          Is this a valid perspective? Very likely it is not. The issue is just that at some point, doing science also needs some common sense judgement abilities.

        • “Business cycle” — “Fire cycle” — “Glacial cycle” … I like this picture.

          On “economic Dawinism” I’m not so sure: What gets selected for what quality? One example pro is General Motors (the junk producer who should have been left to fail). My paradigmatic counter example is Microsoft (makes lots of money by selling grotesque junk, plus is a coevolution factor of information technology leading to grotesque degenerations like the crippled wheel on a mouse button.)

  29. John Baez says:

    Eric wrote:

    I’m finding this to be a bit frustrating.

    Really? I’d be enjoying it immensely if I had caught some obvious errors in a very famous dataset—or least the publicly available version of that dataset.

    The Vostok data here has some minor errors:

    1. At 2666.7 m
    2. At 2674.6 m
    3. At 3057.7 m
    3. At 3072,5 m

    At these points, there is a change in depth and CO2 concentration levels, but no change in age.

    At 3889.45 m, there is no change in depth, no change in age, but a change in CO2 levels.

    You mean 3289.45.

    How can that be?

    Very good question!

    Would you like to contact the people who compiled that data, or would you like me to do it? Either way, I would like to mention the Azimuth Project, since that’s what has gotten us looking at this data, which led you to spot those errors… and it would be a way to let some people know about the Azimuth Project.

    • Eric says:

      Feel free to contact them if you like. Any work I do here, I’m happy to associate with the Azimuth Project of course.

      It would be cool if we had Azimuth email addresses, e.g. Eric.Forgy@azimuthproject.org.

      Before contacting them, it might be good for everyone to have a go and compile any other odd data.

    • Frederik De Roo says:

      It’s probably a silly question because I’m missing the point of your discussion, but what is the problem?

      I suppose depth, age of the ice and carbon dioxide concentration are independently measured. I think they have put great care in measuring. If they then measure some irregularities, so be it.

      At these points, there is a change in depth and CO2 concentration levels, but no change in age.

      I don’t know how they measure (or calculate age) but apparently they simply obtained the same value from their measurements.

      At 3889.45 m, there is no change in depth, no change in age, but a change in CO2 levels. How can that be?

      I suppose they accidentally made two separate measurements at the same position and obtained a different result, yet only for the carbon dioxide concentration. If the difference is within the error margins, I guess it’s not so bad.

      I can understand these irregularities make you want to doubt their dataset, but on the other hand, it may just as well prove they have not messed with the values they obtained from the measurements. Perhaps one could try to find some physically meaningful explanation for these irregularities but I am willing to accept that data are not perfect.

      I would be more interested in seeing the experimental errors on each of the measured quantities.

      • Eric says:

        Hi Frederik,

        I don’t consider these to be major problems. Just something that they should probably supply some explanations for. For example, why are they presenting so many digits if the accuracy is so low?

  30. Florifulgurator says:

    Eric, I can’t help diagnosing denialism in your interpretation of the ice core data plus the “scare graph”. I don’t know what’s the technical term for your particular evasion of the obvious – and I don’t want to go into psychology. Yet I can’t help, your rationalizing is just startling. Perhaps you have been socialising too much with folks having an Inconvenient Gore allergy?

    The one thing the data DOES demonstrate clearly is the presence of cycles. That, to me, is more interesting than the scare chart. Glacial cycles happen and will continue to happen regardless of what humans do. Perhaps carbon emissions do accelerate the cycle, but they do not create it. The cycle happens with or without us. That is the thing that seems the most concerning. Even more so than recent CO2 emissions. Modern civilization just isn’t prepared for the coming ice age.

    Ice age is canceled for now. Next show: Hot age.

    • Eric says:

      Well Mr Florifulgurator,

      First of all, it is difficult taking criticism from someone with your moniker seriously.

      Second, your lack of any kind of scientific rigor is equally startling. It would be very easy, as you have apparently done, to jump on the bandwagon without questioning data presented to me. Why hasn’t anyone noticed flaws in the Vostok data? Talk about inconvenient.

      So far, all I have done is question the scare data being presented to me. In doing so, I have found obvious flaws that as early as 2008, Ahn et al, no one had considered. I have found obvious flaws in “famous” data that you and apparently everyone else had taken for granted.

      I’ve pointed out that splicing Vostok data with more recent data should be done with great care and I’ve asked for references that justify the splicing. I haven’t seen any yet, but expect there to be something forthcoming.

      NOW you are claiming the glacial cycle has ended? You want to be taken seriously?

      Obviously before the next ice age, there will be continued warming. That much can be deduced from the Vostok data. But to claim the cycle is no more? Come on. I’d need a little more reasoning than that.

      • Eric says:

        Sorry. You didn’t claim anything about the glacial cycle ending.

      • Eric says:

        I misinterpreted (I think) what you meant by “The ice age is cancelled”.

        It is not cancelled, but of course global warming will precede the next ice age.

      • Florifulgurator says:

        NOW you are claiming the glacial cycle has ended?

        Not really. But it got a serious hiccup: The Hot Age coming now will last at least a millenium (according to standard climate science). 1) As you see from the graph, it is atypical for the glacial cycle. 2) Given duration and severity, this Hot Age is of immediate concern for the next 50+ generations, so 3) the “coming” ice age is irrelevant for all practical purpose (even if it comes, and comes in time – which can be doubted).

        So, what I’m saying is: For all practical (incl. ethical) purpose you can forget about the glacial cycle.

        You have downplayed Global Warming by erecting the classic straw man of a coming Ice Age. That’s why I could not resist diagnosing denial.

        — Mars Joh. Pictor Florifulgurator (Florifundatorum avatāra as christened by Glorionestus Vastarius von Teisenberg).
        In short, Flori.
        Or: Martin Gisser

        • Eric says:

          I see. Sorry about that. I can understand how that would be frustrating, but it was not my intention to try to divert attention from global warming by mentioning the next ice age. I should have tried to be more clear about that. I definitely appreciate global warming is the immediate concern and will be the primary concern for the next multiple generations.

          However, I’m now beginning to view this as more about the natural glacial cycle rather than the impact of the industrial revolution. If the industrial revolution never happened, global warming would still be an issue we should worry about today because that is what the globe does, i.e. warms and cools via the glacial cycle.

          I don’t intend to disregard the influence the industrial revolution has had, but I do hope to try to quantify it better. I’m not denying the extreme likelihood, but before I’ll feel comfortable actively promoting something, I want to be more comfortable I’ve got the facts straight.

          PS: I will have a look at the references you provided. Thanks!

          PPS: In my numerical experiments here, although crude, I notice that the more the climate is perturbed, the greater the likelihood of a sudden phase transition to an ice age. If the industrial revolution really has significantly altered the glacial cycle (and I wouldn’t be surprised if it has), then it could also lead to an ice age earlier than expected (but not before further warming). Just thinking out loud…

        • Phil Henshaw says:

          Eric,
          I’ve tried to be as communicative as possible, but you appear to have a different kind of belief system, appearing to think it’s possible for the global climate to change like our minds can. The reality is that the climate can’t accomplish a thousand years of change all of a sudden like human beliefs can.

          Maybe you don’t think about why human minds are unable to “see” the physical world, but just have to trust that it’s there. What we actually “see” in our minds is our own self-invented reconstruction of the things around us, an “image”. Just because that image can do all kinds of gymnastics doesn’t mean the physical world can, because images are not the physical reality and change by quite different processes.

          The physical world is always the subject, but all that our minds can collect are pictures. It’s each person’s task to discover some way to coordinate the two realities. Scientists come to trust the limitations of nature, but in fact why the physical world only changes by complexly evolving processes that take time may never be known. Those processes of nature, that take energy and time, are what natural science studies. If we were just studying theory we could make up any one we liked the way politicians, advertisers, commentators on the news, etc., can.
          Phil

        • Eric says:

          Hi Phil,

          I’ve been enjoying your comments and felt like I’ve agreed with and appreciated everything you’ve said. But this last comment leaves me mystified.

          I would be very curious to know what I have ever said that leads you to make the following statement:

          I’ve tried to be as communicative as possible, but you appear to have a different kind of belief system, appearing to think it’s possible for the global climate to change like our minds can.

          I’m wondering if it could be John’s botching up the quotes and attributing things I’ve said to Nathan and vice versa.

          If I believed that, why would I be studying the data so closely? I have to admit, this gave me a good chuckle.

          Anyway, Happy Friday and have a great weekend! Cheers :)

          PS: I would be very interested in actually doing some research. Do you follow the Azimuth forum much? That is probably a better place to get work done than here.

          http://www.math.ntnu.no/~stacey/Mathforge/Azimuth/

          Then anything material that gets accomplished can be transferred to the wiki. At the moment, I’m focusing on the SIO Air Sampling Network data and hope to get a feel for where the observed CO2 concentrations are coming from. i.e we should be able to decompose the total into contributions from fossil fuel burning, volcanoes, etc. Has anyone done that? The few sources I’ve seen seem to attribute 100% of the CO2 to industrial generation, but the justifications for that do not seem very strong. For example, James Hansen claims volcanoes contribute just .0001 ppmv/year, but the Vostok data clearly dispute that.

          Here are some the charts I’m looking at:

          http://www.azimuthproject.org/azimuth/show/Carbon%20image%20gallery

          Here is a corresponding discussion:

          http://www.math.ntnu.no/~stacey/Mathforge/Azimuth/comments.php?DiscussionID=717

        • John Baez says:

          Eric wrote to Phil:

          I would be very curious to know what I have ever said that leads you to make the following statement:

          I’ve tried to be as communicative as possible, but you appear to have a different kind of belief system, appearing to think it’s possible for the global climate to change like our minds can.

          I’m wondering if it could be John’s botching up the quotes and attributing things I’ve said to Nathan and vice versa.

          In case anyone out there reads this and wonders what Eric is talking about: I made a mistake, but it’s fixed now, so you can’t see it.

          I’m not sure why Phil said what he did. Like Phil I’m rather puzzled by Eric’s belief system. But I would describe my puzzlement a bit differently. Something like this:

          A bunch of data indicates that CO2 concentrations are rising faster than they have in the last 400,000 years, and rising to levels that exceed the levels of the last 400,000 years

          Eric seems to consider it likely, or at least possible, that this apparent rapid rise in CO2 is either an experimental error, or the result of ideological bias on the part of the experimenters, or some sort of unexplained natural phenomenon. For example, he writes:

          I’m now beginning to view this as more about the natural glacial cycle rather than the impact of the industrial revolution.

          But I find these ideas puzzling.

          First, I see no reason to suspect that experimental data is drastically wrong, and the experimental data indicates that we’re not seeing the end of a glacial period (it already ended), but a dramatic rise in CO2 beyond its normal interglacial levels. Here I’m talking not only about our favorite chart here:

          but also all the other data I’ve seen.

          Second we’ve already seen here that the amount of CO2 humans are putting into the atmosphere considerably exceeds the amount needed to explain the rise of CO2 concentrations we’re seeing. So to me, it’s not at all surprising that CO2 concentrations are rising so fast right now. The question is why they’re not rising faster!

          (And the answer, it seems, is that a lot of CO2 is going into the ocean, the ground, and plant matter.)

          So, while I think it’s great that Eric is poking into the data and questioning the standard story that most climate scientists believe, the ‘guilty until proven innocent’ approach is not one I would take here, because the standard story seems reasonable.

        • Eric says:

          This is ridiculous. I’m asking questions and I’m doing research to try to answer those questions for myself. It is completely inappropriate to make this about my “belief system”. By doing so only degrades the conversation and frankly makes me think you’re doing bad science.

          So far, I have spent some time playing with the SIO data sets as you can see here:

          http://www.azimuthproject.org/azimuth/show/Carbon%20image%20gallery

          Given the consistency of measurements across SIO sites, I am inclined to accept this data as being accurate. Before signing off completely, I may also like to know exactly how the measurements are taken, e.g. do they measure CO2 directly or is it implied by other methods? There should be easy answers to these questions. It will just take a little digging.

          Once I am comfortable with the SIO data, then there are a few different directions to go. For example, we could try to decompose the observed data into natural contributions and industrial contributions. This seems to be related to your puzzle:

          http://johncarlosbaez.wordpress.com/2011/02/04/carbon-dioxide-puzzles/

          In the puzzle, I believe you were looking at the Mauna Loa data set, but if you look at the Antarctica data set, you see the same thing. A chart giving the comparison is included in the gallery:

          http://www.azimuthproject.org/azimuth/show/Carbon%20image%20gallery

          The first derivatives of both data sets are very consistent.

          I’m glad you bring up the puzzle because I had forgotten about it and it is very relevant. How can there be such dramatic questions about the most recent data and yet you are so willing to accept the accuracy of the Vostok data without question? Are the puzzles with the Vostok data less interesting? Or is it that there is no puzzle because there is only one data set?

          If we take your favorite chart and multiply the Vostok data by a factor of 10 while leaving the SIO data unchanged, would your interpretations change? What about a factor of 5? 2? At what point do you begin to question things? Wouldn’t you like to know what the factor is and whether it is within your comfort zone?

          The Vostok data contains many more puzzles than the SIO data and there is no blog post about that yet. Maybe there should be. That is, unless we do not want to question the data.

          As far as the puzzle is concerned, one possible answer could be that the blue curve is off by a factor of 10 and should be much smaller than the natural contributions to CO2. I’m not saying I believe that, but it could be true. How certain can you be that its not?

          By not acknowledging the lack of certainty in the data sets especially when comparing disparate sources, we do a great disservice to science.

          I truly hope Azimuth can contribute to clearing up these questions. I’m trying. I don’t think it helps anything by making bogus statements about someone’s belief systems. By doing so, makes you no better than a dozen other crackpot sites. Maybe I’m being too optimistic, but I was hoping Azimuth could be better than that.

          PS: By the way, I stumbled onto an interesting site:

          http://www.skepticalscience.com/

          Things are not as cut and dry as we may like them to be, but ignoring the fact is not helping anything.

      • Nathan Urban says:

        Eric,

        I’ve been sitting out this thread so far.

        Under other circumstances, I might have gotten into your questions, and poked into my bibliographical database for references on firn compaction, forward modeling of the relationship between atmospheric and ice core CO2, how much high-frequency variability might get smoothed, etc. They’re interesting questions, after all, and it might be an excuse for me to read more about those subjects.

        However, and I can’t speak for others, your attitude here has convinced me that I don’t really want to spend my spare time trying to help you, or even to argue with you.

        It’s fine to be skeptical of published results. But if you want to interest others in your endeavors, there should be some collegiality. “Hyper-skepticism” to the point of questioning whether there are political motivations to obtain biased data from ice cores, insisting on referring to data graphs as “scare charts meant to scare people” … or even just proclaiming the existence or significance of “data errors” without establishing either their existence or significance …: I know that you think of all these as reasonable skepticism and “objective”, but to others they may appear ridiculously over-the-top, paranoid, prejudiced, or maybe just offensive.

        In short, skepticism works in a social environment when there’s an initial presumption of good faith between parties, even if it may later be proven that some party did act in bad faith. “Trust, but verify.” People are alienated when such a presumption is lacking. This attitude, moreso than any specific dispute, is in my opinion what ultimately led to the irreconcilable hostilities between mainstream climate scientists and the “auditing” crowd. Neither group presumed the other to be acting in good faith, and by now they both appear irreversibly convinced of the opposite.

        • Eric says:

          Hi Nathan,

          Your reaction is understandable, but unfortunate I think. To deny the politics and the unavoidable polarization that comes with these topics related to climate change is a bit of a disservice to both sides.

          It may be true that I’ve overplayed my hand as a devil’s advocate, but I don’t think so. Climate scientists should be at least as hyper skeptical as the hyper skeptics. How else can you stand up to real scrutiny?

          I don’t think any of these minor issues I’ve highlighted represent smoking guns by any means, but so far I have only looked in fair detail at two papers on climate science and in both of them I’ve found mildly embarrassing errors. The bar needs to be raised.

          I refer to John’s favorite chart (at least his favorite in this thread) as a “scare chart” because that is what it is. John admitted the organization that put that chart together does have an agenda. It is spliced from 5 different references: 4 of them are different ice cores and one of them is not even an ice core. How do they justify laying these five distinct charts together? I’m not saying it isn’t justified, but I’d like to know how it is justified.

          Perhaps it is due to the fact it was published in Nature and the number of pages was likely limited, but the paper by Petit et al leaves a lot to be desired in my opinion. Especially in regard to presenting alternative explanations. The certainty it prescribes is unjustified and if my skepticism is considered “hyper”, so be it. We should all be a bit more hyper skeptical considering what is at stake.

          Contrast this to Ahn et al’s paper. This is a very nice paper presenting several possible alternatives and proceeds to explain why those alternatives are unlikely. I like this paper.

          And just a reminder about Zaliapin’s paper.

          Small errors chip away at credibility and I think we should all be a lot more skeptical when data is presented to us.

  31. Eric,

    Your reaction is understandable, but unfortunate I think. To deny the politics and the unavoidable polarization that comes with these topics related to climate change is a bit of a disservice to both sides.

    I think it’s a severe disservice to scientists (in any discipline) to accuse or even suspect them of fudging their data for political reasons, without strong confirmatory evidence of such.

    I don’t think any of these minor issues I’ve highlighted represent smoking guns by any means, but so far I have only looked in fair detail at two papers on climate science and in both of them I’ve found mildly embarrassing errors. The bar needs to be raised.

    First, there is certainly no shortage of “mild errors” in papers published in other disciplines, including physics; I’ve found some myself. But I doubt you’re accusing them of political bias, or claiming that said errors compromise the credibility of physics as a science.

    Second, Zaliapin’s paper notwithstanding, you’re evidently sloppy in identifying errors yourself. You don’t know if the “errors” you claim you’ve found in the Vostok data are actually errors. They may be, or may not be; before making those claims, you had not bothered to verify them with the authors.

    For example, you claim it is an “error” that two data points can have the same depth but different CO2 values. However, as Frederik noted, that’s not necessarily an error. Sometimes more than one data point is measured at a given depth. Sometimes more than one data point is measured at every depth. I’ve certainly worked with such core data myself.

    You don’t know whether this is the case for the Vostok core, but you apparently have no hesitation in advertising this as an “error” and indicting climate science as a whole on this basis.

    I refer to John’s favorite chart (at least his favorite in this thread) as a “scare chart” because that is what it is.

    Frankly, that’s a rude statement.

    John admitted the organization that put that chart together does have an agenda.

    Their stated “agenda”, which appears if you click on the link that John suggested, is as follows:

    “This site was founded by Robert A. Rohde as an extension of his hobby for playing with climate data and sharing his understanding by contributing content to the online encyclopedia Wikipedia under the pseudonym Dragons flight. In many ways, Wikipedia is an excellent venue for such work as anyone may contribute to building the encyclopedic knowledge of the world. However, the format of an encyclopedia can also be fairly constraining and the open community can sometimes lend itself to pointless arguments with people who are more interesting in pushing an agenda than taking an honest look at scientific information.”

    “So in mid 2006, this site was created to allow the science of climate change to be presented in a different and more peaceful format. Like Wikipedia, this site strives to present the science of climate in a well-documented and politically neutral way. Most of this site’s content, at least in the beginning, will be devoted to data. It is the goal of this site to present all such data in a way that is consistent with prevailing scientific wisdom and to note and acknowledge any significant disputes that may exist within the scientific community. It is not our goal to prove or disprove global warming, but merely to document what much of the scientific community believes and give some indication for why they believe it.”

    There’s nothing in there about wanting to scare people. Just the opposite.

    It is spliced from 5 different references: 4 of them are different ice cores and one of them is not even an ice core. How do they justify laying these five distinct charts together?

    If each data set represents absolute atmospheric CO2 concentration, I personally don’t see any problem with overlaying them as long as the y axis is labeled “CO2 concentration”. Why should there be? Even if they didn’t overlap or give consistent estimates of CO2 concentration, they are still estimates of CO2 vs. age and I can’t see any objection to displaying them together as such. They even use different colors to distinguish the different data sets, and both note and cite this.

    Perhaps it is due to the fact it was published in Nature and the number of pages was likely limited, but the paper by Petit et al leaves a lot to be desired in my opinion.

    I have similar opinions about basically every Nature paper, for the reason you suggest (though I wouldn’t use the word “a lot” in this particular case). It’s hard to cram every detail and justification into their page restrictions. For that matter, it can be hard to so within the page limits of any journal; one can always write a near-infinite amount attempting to justify every conclusion to the highest degree. Again, I don’t view this as an indictment against the field.

    We should all be a bit more hyper skeptical considering what is at stake.

    As I said before, if you want to be skeptical about whether the reported CO2 data accurately reflect the actual CO2 levels at that time, fine. There is absolutely nothing wrong with that. But one can be skeptical without being “hyper skeptical”, by which I mean lacking a presumption of good faith among the parties involved.

    In short, despite your proclamations of extreme objectivity, you appear to have rather prejudiced interpretations the field: referring to data you don’t understand as “errors” before verifying that they are, calling data graphs “scare charts” for no justified reason, suspecting political bias in data reporting, etc. Your reply has reaffirmed my earlier decision that I don’t really prefer to spend my free time either helping or arguing with you, now or in the future, so I think I will bow out of this thread now.

    • Eric says:

      I don’t think it is acceptable to accuse anyone blindly of having a bias due to some agenda. Note: I never did that. However, especially when it comes to climate science, I think it is a fair question. Where did they get their funding? Do they have an agenda? These are valid and important questions. These are also questions with easy answers. John answered and I had no issues with his answer or I would have challenged him on it. I didn’t so I don’t.

      I also think it is a valid and important question to ask for the justification for splicing disparate sources of data. I’m a little shocked that having the same units is sufficient for you. It is not for me. If that is what passes for rigor in climate science than any initial biases I may have had are now amplified.

      I won’t argue if you say I’m displaying my own bias. If that is the case, I’m simply trying to compensate for the opposite bias I’m observing here.

      I still believe in the Azimuth Golden Rule. I don’t intend to sit idly and complain from my armchair. I think I’ve already demonstrated my willingness to dig into papers and try to improve things. I’ll continue to do that. For instance, I would like now (time permitting) to work through those 5 sources and try to get comfortable with the splicing. I don’t expect any surprises, but I cannot become comfortable with the data until I’ve worked with it for a while.

      I don’t need you to make progress, but to simply bail out for reasons I consider akin to hyperventilating is unfortunate. If we were sitting in a cafe discussing this, I imagine we wouldn’t be having this silly discussion and you’d see I’m on your side. Too bad.

    • John Baez says:

      Eric wrote:

      I’m a little shocked that having the same units is sufficient for you. It is not for me. If that is what passes for rigor in climate science than any initial biases I may have had are now amplified.

      Since your last sentence here will amplify Nathan’s desire to bow out and cease discussing these issues with you, I think I’ll have to step in and repeat his earlier remark. Nathan never said that “having the same units is sufficient” for plotting these five different-colored lines on a single scale here:

      Each one is somebody’s best attempt to measure the carbon dioxide concentration during a certain time period. So, it’s perfectly sensible to plot them on the same scale.

      Nathan wrote:

      You don’t know if the “errors” you claim you’ve found in the Vostok data are actually errors. They may be, or may not be; before making those claims, you had not bothered to verify them with the authors.

      For example, you claim it is an “error” that two data points can have the same depth but different CO2 values. However, as Frederik noted, that’s not necessarily an error. Sometimes more than one data point is measured at a given depth. Sometimes more than one data point is measured at every depth. I’ve certainly worked with such core data myself.

      Just so everyone knows: I plan to contact the authors and ask them what’s going on with the Vostok ice core data at 2666.7 m, 2674.6 m, 3057.7 m, 3072.5 m and 3289.45 m. I think it’ll be interesting to find out.

      I think it’s commendable that Eric carefully examined the data and found some strange things that deserve explanation. But I think his aggressive approach to this whole discussion has been counterproductive. (Those who don’t know him personally would probably never suspect how nice he is in real life.) In my correspondence with the authors of the Vostok ice core paper, I’ll be my usual polite and friendly self.

      • Eric says:

        But I don’t agree with his oddly aggressive approach to this whole discussion.

        You’re right. My aggressive reactions were to aggressive reactions to what I considered to be sensible questions. An unstable situation.

        For example, I was accused of denialism and “evading the obvious” for asking questions. I was accused of being sloppy in identifying errors when just two days ago I said:

        Hi Frederik,

        I don’t consider these to be major problems. Just something that they should probably supply some explanations for. For example, why are they presenting so many digits if the accuracy is so low?

        It seems obvious to me that the Vostok data contains some minor errors. However, I’m sure they have decent explanations and I’m looking forward to seeing what they have to say. Even you said:

        Really? I’d be enjoying it immensely if I had caught some obvious errors in a very famous dataset—or least the publicly available version of that dataset.

        So if I’m being sloppy, so are you (and I don’t think you are). I think Nathan’s criticisms are unwarranted and unfortunate. He is obviously a great resource that could help a lot if he chose to. If the response you get from the Vostok people demonstrates there are in fact no errors, I’ll happily post a public apology for saying they were. Unlikely, but possible.

        Since it seems to strike a nerve, going forward, I will no longer refer to the “scare chart” as a “scare chart”. However, the justification for splicing the data sets is still unsettled in my opinion.

        I hope it does not come across as denial, but I have not yet seen convincing data suggesting the current global warming is anything more than the normal glacial cycle. This is a statement about my ignorance more than anything and I hope to correct it. So when you ask,

        What is the one best thing everyone could do to slow climate change?

        I still need to ask, is slowing climate change a good/desirable thing? Are we fighting a natural cycle? Should we instead be asking how we can adapt to inevitable and natural climate change?

        For me, before I can address these questions, I need to get comfortable with the data. I’m not comfortable yet, but that is more a function of time spent than any hard drawn conclusions.

        • Eric says:

          I’m home sick today, so although not ideal circumstances for doing good research (or being in a good mood for that matter), I tried to make some progress. I found a link to the following video from one of the Azimuth wiki pages:

          The 8 Minute Epoch: 65 Million Years with James Hansen

          The video starts out great. I was feeling relieved that finally someone who sounds convincing is saying the things I want to hear to help me come to grips with the human impact on climate change.

          He begins with a quote that hit close to home for me:

          It is arrogant to think that humans can control climate or that we know enough to say that today’s climate is the best for the planet.

          This quote is attributed to Michael Griffin, former NASA Administrator. Wikipedia provides an additional quote:

          “I have no doubt that global — that a trend of global warming exists. I am not sure that it is fair to say that it is a problem we must wrestle with. To assume that it is a problem is to assume that the state of Earth’s climate today is the optimal climate, the best climate that we could have or ever have had and that we need to take steps to make sure that it doesn’t change.

          First of all, I don’t think it’s within the power of human beings to assure that the climate does not change, as millions of years of history have shown, and second of all, I guess I would ask which human beings – where and when – are to be accorded the privilege of deciding that this particular climate that we have right here today, right now is the best climate for all other human beings. I think that’s a rather arrogant position for people to take.”

          Anyway, I was hoping the remainder of the presentation would convince me once and for all.

          It almost did until an irritating artistic use of data was made. To convince the audience that humans are in control of CO2, he compared it to the natural CO2 production from volcanoes, which he claimed to be the primary source of natural CO2 in the atmosphere. He claimed that natural sources of CO2 produce .0001 ppm/year and that humans produce 2 ppm/year.

          If we look at the SIO Air Sampling Network data, we see that the total ppm change from 1958 to 2007 is roughly 65 ppm. This gives an average of roughly 1.3 ppm/year. This is human contribution PLUS the natural contribution that would be there anyway. So the human contribution is surely less than 1.3 ppm/year. Where does he get 2 ppm/year from?

          As I have said before, I suspect the historical CO2 concentration changes throughout previous glacial cycles could be more pronounced than the Vostok data suggests due to deep diffusion in the core. However, if I ignore that and take the Vostok data at face value, I see changes in CO2 concentration of more than .3 ppm/year 313,000 years ago. Long before the industrial revolution. And the numbers observed in the Vostok data are averages over 1000-1500 years. How can we be sure there weren’t much larger spikes than that?

          Granted .3 ppm/year is an extreme value. Eyeballing it, I would guestimate the average to be on the order of +/- .03 ppm/year. But again, this is averaged over long periods of time, i.e millennia. There could be significantly higher variations on shorter time scales.

          Unfortunately, Hansen’s exaggerations lost me.

          PS: Hansen also has a quote about Michael Griffin on Wikipedia:

          Griffin’s comments showed “arrogance and ignorance”, as millions will likely be harmed by global warming.

          Of the two, I would side with Griffin.

          PPS: Is there a way to directly estimate industrial contributions and natural contributions to atmospheric CO2 in such a way that is consistent with the observed SIO total data?

          PPPS: Griffin’s last day as NASA Administrator was the day Obama was inaugurated. Go figure. Another great legacy.

        • Eric says:

          I see how you can get 2 ppm/yr now. Have a look at the gallery.

          If you look at the annual variations, it is quite a noisy plot, but you can pick the data point you like to get 2 ppm/yr. However, it could easily change by 1 ppm/yr on an annual basis depending on which time period you choose.

        • Frederik De Roo says:

          Eric said:

          This gives an average of roughly 1.3 ppm/year. This is human contribution PLUS the natural contribution that would be there anyway. So the human contribution is surely less than 1.3 ppm/year. Where does he get 2 ppm/year from?

          Actually I think he based the 2 ppm/year on recent data. But since I haven’t got any source to claim that, let us briefly reason as follows (I’m just pulling this out of my hat):

          It appears that the curve you plotted has a positive second derivative. So if James Hansen didn’t average from 1958 till now but concentrated instead on, say, the period 1990-now (which is more relevant for policy reasons because it is closer to current emissions) the average would be higher than 1.3 ppm/year, say, maybe 1.6 ppm/year (I’m pulling this out of my hat without taking the effort to look at the chart whether that’s a reasonable figure). Because decimal points might not very well accepted in a talk, he rounds off and 1.6 becomes 2. Nothing more than that.

          I can certainly agree (based on your comments of the talk, because I haven’t seen the talk myself) that he could have been more precise while stating this figure, but I think any such lack of precision has more to do with the idea of a giving talk, rather than that his subject was about climate.

        • Frederik De Roo says:

          Eric, I posted my last comment without seeing the Antartica plot.

          To estimate global carbon emissions for each year, it would be much more precise to average carbon dioxide concentration measured at as many stations possible, instead of focusing on only one. I’m not sure as to how well mixed the atmosphere is, but I would certainly not choose a station at Antartica to represent the whole earth (not for carbon dioxide, and certainly not for ozone)

          I think usually people look at Mauna Loa, if they look at a single station. I guess it’s because it’s located in a relatively unpolluted area, close to the equator.

        • Eric says:

          Hi Frederik,

          I’ve now added a new chart to the gallery comparing Mauna Loa and Antarctica. The CO2 concentration measurements across all SIO sites are very consistent.

          I chose Antarctica for the illustration simply because it doesn’t seem to matter which site you choose and Antarctica has more data. The Mauna Loa stops in 2003. Antarctica goes to 2007.

          I’ve also included a comparison of the rate of change in CO2 for both Mauna Loa and Antarctica in the gallery. The story is the same either way.

        • Florifulgurator says:

          Eric, which gallery? Possibly the non-working link in your above comment?

        • Eric says:

          Hmm. The links didn’t work in the last post either. Try the Azimuth Forum or go directly to the Azimuth Wiki:

          http://www.azimuthproject.org/azimuth/show/Carbon+image+gallery

        • Phil Henshaw says:

          Eric, you need to look at the fabric of science, not try to remake your image of nature from the tiny weaving back and forth of its threads…

          Whenever people try to see nature as fitting their images they nearly always succeed, but then find more and more other things around them they have to explain that they have no evidence for (like the possibility of a broad conspiracy to politicize their data within some disciplines of science, that nearly all other scientists take no interest in, etc. ).

          That becomes an endless expanding chore that produces no result but frustration, rather the opposite. The task that absorbs science is the question of how to settle questions, rather than how to keep getting more and more lost in discrepancies trying to defend preferred beliefs.

      • Florifulgurator says:

        I’ve been away on my classic June birthdays roundtrip (incl. some catastrophe) and now sitting @ work. So I haven’t examined the whole thread yet…

        While slowly driving thru a global warming strong rain event in the middle of last night it struck me that there’s perhaps an open question here:

        How would the “scare graph” look like when modelled according to firn compactification and CO2-in-ice-core diffusion?

        (Assume e.g. the ridiculously optimistic scenario that CO2 will max at 550ppm (forget about 450…, cf. old Proc. Roy. Acad. paper) in say 2050 and will then decline according to the standard old carbon cycle models.)

        Could be a cool Azimuth numerics exercise.

  32. John Baez says:

    Some people in this discussion seem to be having trouble quoting each other: I’ve been very distracted by the quantum gravity conference I’m at, but I’ve been spending most of my tiny time on this blog fixing up quotes.

    The best way to quote someone is to type something like this:

    <blockquote>
    Here is a nice quote.
    </blockquote>

    which produces

    Here is a nice quote.

    There are other less nice ways to do it. The really bad ways make it impossible to tell when you’re actually saying something and when you’re quoting someone else saying something.

    I thank Frederik de Roo for pointing out some of the these problems. I hope I’ve fixed them all!

    On a more substantive note, I’m glad Martin (=Florifulgurator) and Eric are cooperating and figuring out some facts.

  33. John Baez says:

    Eric wrote:

    This is ridiculous. I’m asking questions and I’m doing research to try to answer those questions for myself. It is completely inappropriate to make this about my “belief system”.

    I was trying to find out why you seem to assign a low a priori probability that the consensus view of climate scientists is correct. This “hyper skeptical” attitude, as you call it, seems to be based on some belief system very different from mine. I don’t understand it.

    But never mind: it was a mistake for me to raise this question, and I’m sorry. We’ll make lots more progress if we focus on the data.

    How can there be such dramatic questions about the most recent data and yet you are so willing to accept the accuracy of the Vostok data without question?

    First, I don’t accept that data ‘without question’.

    Second, my questions about the more recent data have nothing to do with the Vostok data: they’re obtained by completely different means, they raise different issues, etc.

    Are the puzzles with the Vostok data less interesting?

    Right. I think other questions are vastly more urgent. I have a limited amount of time to spend on this stuff, so I want to focus on questions that give the biggest bang for the buck. The accuracy of the Vostok data isn’t near the top of my list. We’ve touched on some other things that are, for example:

    1) What causes the glacial cycles?

    2) Why does CO2 lag behind temperature rise at some points in the climate record?

    3) Where is the CO2 produced by burning fossils going?

    Mind you, lots of professional climate scientists are already publishing papers about these puzzles. A lot is already known, and so far I’ve learned just a little. I don’t want to jump in and start making bold pronouncements. But I think these areas hold more uncertainty and thus more bang for the buck.

    Or is it that there is no puzzle because there is only one data set?

    There’s not just one data set: on this thread I already mentioned that there are 19 major ice core projects in Greenland and 12 in Antarctica, including EPICA, which goes back even further than Vostok.

    If you want to study the accuracy of the Vostok ice core data, you could compare it to EPICA and some of the others. I showed you a graph comparing deuterium for Vostok and EPICA: that’s a temperature proxy. But what about CO2?

    So far, I have spent some time playing with the SIO data sets as you can see here:

    http://www.azimuthproject.org/azimuth/show/Carbon%20image%20gallery

    Great! I’m really glad you’re doing this.

    Given the consistency of measurements across SIO sites, I am inclined to accept this data as being accurate. Before signing off completely, I may also like to know exactly how the measurements are taken, e.g. do they measure CO2 directly or is it implied by other methods? There should be easy answers to these questions. It will just take a little digging.

    It’s certainly easier than digging an ice core.

    If we take your favorite chart and multiply the Vostok data by a factor of 10 while leaving the SIO data unchanged, would your interpretations change?

    Of course! It would mean that present-day CO2 levels are dramatically below what they’ve been during the last 420,000 years—instead of dramatically above them, as shown here:

    If you said the dark blue line here needs to be 10 times higher to be correct, then you’d be saying CO2 levels historically varied between 2000 and 3000 ppm. If this were true—I’m quite sure it’s not—it would utterly overthrow everything I believe about climate science.

    What about a factor of 5? 2?

    If you said the dark blue line needs to be twice high to be correct, you’d be saying CO2 levels historically varied between 400 and 600 ppm. This would still mean that present-day CO2 levels are dramatically below what they’ve been in the last 420,000 years. So that would still come as an utter shock to me.

    At what point do you begin to question things? Wouldn’t you like to know what the factor is and whether it is within your comfort zone?

    If the historical peaks of CO2 were above the peak we’re heading towards now, I wouldn’t be worrying as much about the CO2 concentration we’re heading towards now. I would mainly be worrying about the rapid rate at which we’re heading there.

    Very very very roughly, we’re heading to a peak somewhere between 400 ppm (if by some miracle world leaders stop CO2 emissions this year) and 1200 ppm (if we don’t bother limiting CO2 emissions at all).

    So: for this future peak to be only as tall as the peaks we’ve seen over the last 420,000 years, we’d need to move up that dark blue line so it’s between 4/3 and 4 times as high as it is now!

    So: my opinions on climate change would be dramatically affected if the Vostok estimates of previous peak CO2 levels were about 33% too low.

    The Vostok data contains many more puzzles than the SIO data and there is no blog post about that yet. Maybe there should be. That is, unless we do not want to question the data.

    If you want to keep raising questions about the Vostok ice core, go ahead. If you build a convincing case that their estimate of previous peak CO2 levels is at least 20% too low, I’ll get interested enough to blog about it. Meanwhile we can talk about it here or on the Forum.

    So far, I see many other questions that promise more bang for the buck. I listed three, but there are plenty of others, such as:

    4) What are the pros and cons of various kinds of nuclear reactors?

    5) What’s the maximum amount of wind and/or solar power that we can feasibly generate in the next 5, 10, 20 or 30 years?

    6) What are the best ways to increase efficiency of photovoltaic solar cells? What can physicists do here?

    7) What are the best ways to increase efficiency of concentrated solar power? What can physicists do here?

    8) What are the best ways to increase the accuracy of climate projections? What can physicists, mathematicians and computer scientists do here?

    9) What are the pros and cons of the geoengineering ideas mentioned by Benford?

    10) What are the likely effects of rising temperatures on storm activity: floods, hurricanes, tornadoes and the like?

    11) What are the likely effects of rising temperatures on dry regions, for example in the American Southwest and the Sahel?

    That’s 11 blog posts I really want to write, that I haven’t had time for yet. If anyone wants to write one, please let me know!

    • Eric says:

      I see.

      I was trying to find out why you seem to assign a low a priori probability that the consensus view of climate scientists is correct.

      Somewhere along the lines there has been a miscommunication. I do not assign a low a priori probability that the consensus view is correct. Quite the opposite. I’ve tried to be very conservative and hedging my statements by saying things like, “I don’t expect any smoking guns” and “I don’t expect any surprises”.

      Here are some exact quotes:

      Starting with the raw data, it would be interesting to test the robustness ourselves. This could be an interesting Azimuth project. To be honest, I do not expect any smoking guns. The results are likely robust to the models used, but seeing that robustness explicitly would help give me comfort.

      and

      For instance, I would like now (time permitting) to work through those 5 sources and try to get comfortable with the splicing. I don’t expect any surprises, but I cannot become comfortable with the data until I’ve worked with it for a while.

      If I am to commit myself to this project, and I probably never would if you hadn’t started Azimuth, I simply want to be sure that I’m not being a misguided fanatic. The chances are small for sure, but even a slight chance that I dedicate a significant part of my life to a fabrication is worth looking into. Many smart people have serious doubts.

      I intend to keep an open mind and a part of that includes not wanting to assume the conclusion before I even begin working. The more I want the climate science to be accurate, the more I need to challenge it. If it stands up to my questioning, I’ll buy into it more and do whatever I can to help. I never do anything half way.

      • John Baez says:

        Eric wrote:

        Somewhere along the lines there has been a miscommunication. I do not assign a low a priori probability that the consensus view is correct.

        Okay, great! It wasn’t just me who got this impression. It was also Martin, Nathan and Phil: everyone who replied to you, in short. The quotes you cite sound very reasonable. Other things you wrote sounded very different. But let’s bury this dispute, if we can, and focus on the science.

  34. Tim van Beek says:

    12) What can be done to save power, starting with zero energy buildings, and not ending with smart grids.

    • John Baez says:

      Sounds great!

      I think your first blog post here was great, and I’m looking forward to more. If you write about climate models and software design, that still leaves a huge amount for me. I hope others join in.

You can use HTML in your comments. You can also use LaTeX, like this: $latex E = m c^2 $. The word 'latex' comes right after the first dollar sign, with a space after it.

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s

Follow

Get every new post delivered to your Inbox.

Join 2,827 other followers