The first covered the basics of climate science as related to global warming. This one moves on to consider technologies for removing carbon dioxide from the air.
I hope you keep the following warning in mind as you read on:
I’m focused here on trying to understand the narrowly technical aspects, not on the political aspects, despite those being crucial. This is meant to be a review of the technical literature, not a political statement. I worried that writing a blog purely on the topic of technological intervention in the climate, without attempting or claiming to do justice to the social issues raised, would implicitly suggest that I advocate a narrowly technocratic or unilateral approach, which is not my intention. By focusing on technology, I don’t mean to detract from the importance of the social and policy aspects.
The technological issues are worth studying on their own, since they constrain what’s possible. For example: to draw down as much CO2 as human civilization is emitting now, with trees their peak growth phase and their carbon stored permanently, could be done by covering the whole USA with such trees.
Adam Marblestone is a research scientist at Google DeepMind studying connections between neuroscience and artificial intelligence. Previously, he was Chief Strategy Officer of the brain-computer interface company Kernel, and a research scientist in Ed Boyden’s Synthetic Neurobiology Group at MIT working to develop new technologies for brain circuit mapping. He also helped to start companies like BioBright, and advised foundations such as the Open Philanthropy Project.
Now, like many of us, he’s thinking about climate change, and what to do about it. He writes:
In this first of three posts, I attempt an outsider’s summary of the basic physics/chemistry/biology of the climate system, focused on back of the envelope calculations where possible. At the end, I comment a bit about technological approaches for emissions reductions. Future posts will include a review of the science behind negative emissions technologies, as well as the science (with plenty of caveats, don’t worry) behind more controversial potential solar radiation management approaches. This first post should be very basic for anyone “in the know” about energy, but I wanted to cover the basics before jumping into carbon sequestration technologies.
Check it out! I like the focus on “back of the envelope” calculations because they serve as useful sanity checks for more complicated models… and also provide a useful vaccination against the common denialist argument “all the predictions rely on complicated computer models that could be completely wrong, so why should I believe them?” It’s a sad fact that one of the things we need to do is make sure most technically literate people have a basic understanding of climate science, to help provide ‘herd immunity’ to everyone else.
The ultimate goal here, though, is to think about “what can technology do about climate change?”
John always tells me to write short, sweet, and clear. Knowing that his advice is supreme on these matters, I’ll try to write mini-posts in between the bigger ones. But… not this time – the topic is too good.
Work smarter, not (just) harder.
Today I got an email from Bill McKibben, founder of 350.org. (350 parts per million, the concentration of CO2 considered a “safe upper limit” for Earth, by NASA scientists James Hansen. We’re soaring past 415ppm.) In preparation for the global climate strike, Bill wants to share an important idea: divesting from fossil fuels may be our greatest lever.
I’ll pluck paragraphs to quote, but please read the whole article; this is an extremely important and practical idea for addressing the crisis. And it’s well written… the first sentence sounds fairly Baezian.
I’m skilled at eluding the fetal crouch of despair—because I’ve been working on climate change for thirty years, I’ve learned to parcel out my angst, to keep my distress under control. But, in the past few months, I’ve more often found myself awake at night with true fear-for-your-kids anguish. This spring, we set another high mark for carbon dioxide in the atmosphere: four hundred and fifteen parts per million, higher than it has been in many millions of years. The summer began with the hottest June ever recorded, and then July became the hottest month ever recorded. The United Kingdom, France, and Germany, which have some of the world’s oldest weather records, all hit new high temperatures, and then the heat moved north, until most of Greenland was melting and immense Siberian wildfires were sending great clouds of carbon skyward. At the beginning of September, Hurricane Dorian stalled above the Bahamas, where it unleashed what one meteorologist called “the longest siege of violent, destructive weather ever observed” on our planet.
Bill emphasizes that change has moved far too slowly, of course. But he’s spent the past week with Greta Thunberg and many other activists, and one can tell that he really is heartened.
It seems that there are finally enough people to make an impact… what if there were an additional lever to pull, one that could work both quickly and globally?
The answer: money.
Today it is large corporations which have the greatest power over daily life, and they are far more susceptible to pressure and change then the insulated bureaucracies of governments.
Thankfully Bill and many others knew this years ago, and started a divestment campaign of breathtaking magnitude:
Seven years ago, 350.org helped launch a global movement to persuade the managers of college endowments, pension funds, and other large pots of money to sell their stock in fossil-fuel companies. It has become the largest such campaign in history: funds worth more than eleven trillion dollars have divested some or all of their fossil-fuel holdings.
And it has been effective: when Peabody Energy, the largest American coal company, filed for bankruptcy, in 2016, it cited divestment as one of the pressures weighing on its business, and, this year, Shell called divestment a “material adverse effect” on its performance.
The movement is only growing, accelerating, and setting its sights on the big gorillas. The main sectors: banking, asset management, and insurance.
Consider a bank like, say, JPMorgan Chase, which is America’s largest bank and the world’s most valuable by market capitalization. In the three years since the end of the Paris climate talks, Chase has reportedly committed 196 billion dollars in financing for the fossil-fuel industry, much of it to fund extreme new ventures: ultra-deep-sea drilling, Arctic oil extraction, and so on. In each of those years, ExxonMobil, by contrast, spent less than 3 billion dollars on exploration, research, and development. $196B is larger than the market value of BP; it dwarfs that of the coal companies or the frackers. By this measure, Jamie Dimon, the C.E.O. of JPMorgan Chase, is an oil, coal, and gas baron almost without peer.
But here’s the thing: fossil-fuel financing accounts for only about 7% of Chase’s lending and underwriting. The bank lends to everyone else, too—to people who build bowling alleys and beach houses and breweries. And, if the world were to switch decisively to solar and wind power, Chase would lend to renewable-energy companies, too. Indeed, it already does, though on a much smaller scale… It’s possible to imagine these industries, given that the world is now in existential danger, quickly jettisoning their fossil-fuel business. It’s not easy to imagine—capitalism is not noted for surrendering sources of revenue. But, then, the Arctic ice sheet is not noted for melting.
Bill elucidates the fact that it is critical to effect the divestment of giants like Chase, Blackrock, and Chubb. Even if these targets are quite hard, this method of action applies to every aspect of the economy, and empowers every single individual (more below). If the total divestment is spread over a decade, it can be done without serious economic instability. And if done well, it will spur tremendous growth in the renewable energy sector and ecological economy in general, as public consciousness opens up to these ideas on a large scale.
I want to keep giving quotes, but you can read it. (If anyone is out of free articles for New Yorker, I can send a text file.) I’ll contribute a few of my own thoughts, expanding on stuff implicit in the article; and then this topic can be continued with another post.
Divesting is a truly powerful lever, for several reasons.
First, money talks. Many people who have been misled by modern society have the following equation in their heads:
money = value
These people, being overwhelmed with social complexity, have lifted the “burden” of large-scale ethics off of their shoulders and into a blind faith in the economic system – thinking “well, if enough people have the right idea, then capitalism will surely head in the right direction.”
Of course, after not too long, we find that this is not the case. But their thinking has not changed, and we need a way to communicate with them. While it may feel strange and wrong to reformulate the message from “ethical imperative” to “financial risk”, this is the way to get through to many people in powerful places. When you read about success stories, it is effective, especially considering all the time spent mired in anthropogenic-warming skepticism.
Second, social pressure is now a real force in the world. We can bend competition to our will: incentivize companies to better practices, and when one capitulates, the others in that sphere follow. It has happened many times, and the current is only getting stronger.
Though if we want to fry bigger fish than no-straws, we need to sharpen our collective tactics. It will of course be more systematic and penetrating than shaming companies on Twitter. The article includes great examples of this; it would be awesome to discuss more ideas in the comments.
Third, everyone can help this way, directly and significantly. Everyone has a bank account. It is not difficult, nor seriously detrimental, to switch to a credit union. The divestment campaign can be significantly accelerated by a movement of concerned citizens making this transition.
(My family uses Chase. When I was spending quality time back home, I asked my parents how the value of a bank is anything more than secure money storage. The main thing they mentioned was loans – but they admitted that the biggest and best loan they ever took was through a credit union. The reasons simply did not add up. I plan to show them this article, and I’ll try to have an earnest conversation with them. I really hope they understand, because I know they are rational and good people.)
It’s all but impossible for most of us to stop using fossil fuels immediately, especially since, in many places, the fossil-fuel and utility industries have made it difficult and expensive to install solar panels on your roof. But it’s both simple and powerful to switch your bank account: local credit unions and small-town banks are unlikely to be invested in fossil fuels, and Beneficial State Bank and Amalgamated Bank bring fossil-free services to the West and East Coasts, respectively, while Aspiration Bank offers them online. (And they’re all connected to A.T.M.s.)
This all could, in fact, become one of the final great campaigns of the climate movement—a way to focus the concerted power of any person, city, and institution with a bank account, a retirement fund, or an insurance policy on the handful of institutions that could actually change the game. We are indeed in a climate moment—people’s fear is turning into anger, and that anger could turn fast and hard on the financiers. If it did, it wouldn’t end the climate crisis: we still have to pass the laws that would actually cut the emissions, and build out the wind farms and solar panels. Financial institutions can help with that work, but their main usefulness lies in helping to break the power of the fossil-fuel companies.
The economy is far more responsive to changes in the collective ethos than the government. This is how people can directly express their values every day, with every bit of earning they have. We are recognizing that the public mindset is changing, and we can now take heart and leverage society in the right direction.
Conjecture The critical science of our time has the form:
This is why John Baez brought together so many capable people for the Azimuth Project. I hope that we can connect with the new momentum and coordinate on something great. Even in just the last post there were some really good ideas. I really look forward to hearing more. Thanks.
Hello, I’m Christian Williams. I study category theory with John Baez at UC Riverside. I’ve written two posts on Azimuth about promising distributed computing endeavors. I believe in the power of applied theory – that’s why I left my life in Texas just to work with John. But lately I’ve begun to wonder if these great ideas will help the world quickly enough.
I want to discuss the big picture, and John has kindly granted me this platform with such a diverse, intelligent, and caring audience. This will be a learning process. All thoughts are welcome. Thanks for reading.
….. I am the master of my fate, I am the captain of my soul.
It’s important to be positive. Humanity now has a global organization called the United Nations. Just a few years ago, members signed an amazing treaty called The Paris Agreement. The parties and signatories:
… basically everyone.
By ratifying this document, the nations of the world agreed to act to keep global warming below 2C above pre-industrial levels – an unparalleled environmental consensus. (On Azimuth, in 2015.) It’s not mandatory, and to me that’s not the point. Together we formally recognize the crisis and express the intent to turn it around.
Except… we really don’t have much time.
We are consistently finding that the ecological crisis is of a greater magnitude and urgency than we thought. The report that finally slapped me awake is the IPCC 2018, which explains the difference between 2C and 1.5C in terms of total devastation and lives, and states definitively:
We must reduce global carbon emissions by 45% by 2030, and by 100% by 2050 to keep within 1.5C. We must have strong negative emissions into the next century. We must go well beyond our agreement, now.
So… how is our progress on the agreement? That is complicated, and a whole analysis is yet to be done. Here is the UN progress tracker. Here is an NRDC summary. Some countries are taking significant action, but most are not yet doing enough. Let that sink in.
However, the picture is much deeper than only national. Reform sparks at all levels of society: a US politician wanting to leave the agreement emboldened us to form the vast coalition We Are Still In. There are many initiatives like this, hundreds of millions of people rising to the challenge. A small selection:
On the national level, we must make concrete, compulsory commitments. If they do not soon then we must demand louder, or take their place. The same week as the summit, there will be a global climate strike. It is crucial that all generations join the youth in these demonstrations.
We must change how the world works. We have reached global awareness, and we have reached an ethical imperative.
A quick question: if somebody wants to donate money to reduce his or her carbon footprint, which org(s) would you recommend that he or she donate to?
Do you have a good answer to this? I don’t want answers that deny the premise. We’re assuming someone wants to donate money to reduce his or her carbon footprint, and choosing an organization based on this. We’re not comparing this against other activities, like cutting personal carbon emissions or voting for politicians who want to cut carbon emissions.
Here they list various ways to offset your carbon emissions, currently with prices between $11 and $18 per tonne.
The Gold Standard Foundation is a non-profit foundation headquartered in Geneva that tries to ensure that carbon credits are real and verifiable and that projects make measurable contributions to sustainable development.
A carbon dioxide scrubber is any sort of gadget that removes carbon dioxide from the air. There are various ways such gadgets can work, and various things we can do with them. For example, they’re already being used to clean the air in submarines and human-occupied spacecraft. I want to talk about carbon dioxide scrubbers as a way to reduce carbon emissions from burning fossil fuels, and a specific technology for doing this. But I don’t want to talk about those things today.
Why not? It turns out that if you start talking about the specifics of one particular approach to fighting global warming, people instantly want to start talking about other approaches they consider better. This makes some sense: it’s a big problem and we need to compare different approaches. But it’s also a bit frustrating: we need to study different approaches individually so we can know enough to compare them, or make progress on any one approach.
I mainly want to study the nitty-gritty details of various individual approaches, starting with one approach to carbon scrubbing. But if I don’t say anything about the bigger picture, people will be unsatisfied.
So, right now I want to say a bit about carbon dioxide scrubbers.
The first thing to realize—and this applies to all approaches to battling global warming—is the huge scale of the task. In 2018 we put 37.1 gigatonnes of CO2 into the atmosphere by burning fossil fuels and making cement.
That’s a lot! Let’s compare some of the other biggest human industries, in terms of the sheer mass being processed.
Cement production is big. Global cement production in 2017 was about 4.1 gigatonnes, with China making more than the rest of the world combined, and a large uncertainty in how much they made. But digging up and burning carbon is even bigger. For example, over 7 gigatonnes of coal is being mined per year. I can’t find figures on total agricultural production, but in 2004 we created about 5 gigatonnes of agricultural waste. Total grain production was just 2.53 gigatonnes in 2017. Total plastic production in 2017 was a mere 348 megatonnes.
So, to use technology to remove as much CO2 from the air as we’re currently putting in would require an industry that processes more mass than any other today.
I conclude that this won’t happen anytime soon. Indeed David McKay calls all methods of removing CO2 from air “the last thing we should talk about”. For now, he argues, we should focus on cutting carbon emissions. And I believe that to do that on a large enough scale requires economic incentives, for example a carbon tax.
But to keep global warming below 2°C over pre-industrial levels, it’s becoming increasingly likely that we’ll need negative carbon emissions:
Indeed, a lot of scenarios contemplated by policymakers involve net negative carbon emissions. Often they don’t realize just how hard these are to achieve! In his talk Mitigation on methadone: how negative emissions lock in our high-carbon addiction, Kevin Anderson has persuasively argued that policymakers are fooling themselves into thinking we can keep burning carbon as we like now and achieve the necessary negative emissions later. He’s not against negative carbon emissions. He’s against using vague fantasies of negative carbon emissions to put off confronting reality!
It is not well understood by policy makers, or indeed many academics, that IAMs [integrated assessment models] assume such a massive deployment of negative emission technologies. Yet when it comes to the more stringent Paris obligations, studies suggest that it is not possible to reach 1.5°C with a 50% chance without significant negative emissions. Even for 2°C, very few scenarios have explored mitigation without negative emissions, and contrary to common perception, negative emissions are also prevalent in higher stabilisation targets (Figure 2). Given such a pervasive and pivotal role of negative emissions in mitigation scenarios, their almost complete absence from climate policy discussions is disturbing and needs to be addressed urgently.
Read his whole article!
Pondering the difficulty of large-scale negative carbon emissions, but also their potential importance, I’m led to imagine scenarios like this:
In the 21st century we slowly wean ourselves of our addiction to burning carbon. By the end, we’re suffering a lot from global warming. It’s a real mess. But suppose our technological civilization survives, and we manage to develop a cheap source of clean energy. And once we switch to this, we don’t simply revert to our old bad habit of growing until we exhaust the available resources! We’ve learned our lesson—the hard way. We start trying to cleaning up the mess we made. Among other things, we start removing carbon dioxide from the atmosphere. We then spend a century—or two, or three—doing this. Thanks to various tipping points in the Earths’ climate system, we never get things back to the way they were. But we do, finally, make the Earth a beautiful place again.
If we’re aiming for some happy ending like this, it may pay to explore various ways to achieve negative carbon emissions even if we can’t scale them up fast enough to stop a big mess in the 21st century.
(Of course, I’m not suggesting this strategy as an alternative to cutting carbon emissions, or doing all sorts of other good things. We need a multi-pronged strategy, including some prongs that will only pay off in the long run, and only if we’re lucky.)
If we’re exploring various methods to achieve negative carbon emissions, a key aspect is figuring out economically viable pathways to scale up those methods. They’ll start small and they’ll inevitably be expensive at first. The ones that get big will get cheaper—per tonne of CO2 removed—as they grow.
This has various implications. For example, suppose someone builds a machine that sucks CO2 from the air and uses it to make carbonated soft drinks and to make plants grow better in greenhouses. As I mentioned, Climeworks is actually doing this!
In one sense, this is utterly pointless for fighting climate change, because these markets only use 6 megatonnes of CO2 annually—less than 0.02% of how much CO2 we’re dumping into the atmosphere!
But on the other hand, if this method of CO2 scrubbing can be scaled up and become cheaper and cheaper, it’s useful to start exploring the technology now. It could be the first step along some economically viable pathway.
I especially like the idea of CO2 scrubbing for coal-fired power plants. Of course to cut carbon emissions it would be better to ban coal-fired power plants. But this will take a while:
So, we can imagine an intermediate regime where regulations or a carbon tax make people sequester the CO2 from coal-fired power plants. And if this happens, there could be a big market for carbon dioxide scrubbers—for a while, at least.
I hope we can agree on at least one thing: the big picture is complicated. Next time I’ll zoom in and start talking about a specific technology for CO2 scrubbing.
It will help us begin to understand the economics. But some numbers may have changed since this was written! Also, the passage I’m quoting focuses on taking carbon dioxide out of the air. This not really what I’m researching now: I’m actually interested in removing carbon dioxide from the exhaust from coal-fired power plants, at least until we manage to eliminate these plants. But the two problems have enough similarities that it’s worth looking at the former.
Here is what McKay says:
The cost of sucking
Today, pumping carbon out of the ground is big bucks. In the future, perhaps pumping carbon into the ground is going to be big bucks. Assuming that inadequate action is taken now to halt global carbon pollution, perhaps a coalition of the willing will in a few decades pay to create a giant vacuum cleaner, and clean up everyone’s mess.
Before we go into details of how to capture carbon from thin air, let’s discuss the unavoidable energy cost of carbon capture. Whatever technologies we use, they have to respect the laws of physics, and unfortunately grabbing CO2 from thin air and concentrating it requires energy. The laws of physics say that the energy required must be at least 0.2 kWh per kg of CO2 (table 31.5). Given that real processes are typically 35% efficient at best, I’d be amazed if the energy cost of carbon capture is ever reduced below 0.55 kWh per kg.
Now, let’s assume that we wish to neutralize a typical European’s CO2 output of 11 tons per year, which is 30 kg per day per person. The energy required, assuming a cost of 0.55 kWh per kg of CO2, is 16.5 kWh per day per person. This is exactly the same as British electricity consumption. So powering the giant vacuum cleaner may require us to double our electricity production – or at least, to somehow obtain extra power equal to our current electricity production.
If the cost of running giant vacuum cleaners can be brought down, brilliant, let’s make them. But no amount of research and development can get round the laws of physics, which say that grabbing CO2 from thin air and concentrating it into liquid CO2 requires at least 0.2 kWh per kg of CO2.
Now, what’s the best way to suck CO2 from thin air? I’ll discuss four technologies for building the giant vacuum cleaner:
A. chemical pumps;
C. accelerated weathering of rocks;
D. ocean nourishment.
A. Chemical technologies for carbon capture
The chemical technologies typically deal with carbon dioxide in two steps.
First, they concentrate CO2 from its low concentration in the atmosphere; then they compress it into a small volume ready for shoving somewhere (either down a hole in the ground or deep in the ocean). Each of these steps has an energy cost. The costs required by the laws of physics are shown in table 31.5.
In 2005, the best published methods for CO2 capture from thin air were quite inefficient: the energy cost was about 3.3 kWh per kg, with a financial cost of about $140 per ton of CO2. At this energy cost, capturing a European’s 30 kg per day would cost 100 kWh per day – almost the same as the European’s energy consumption of 125 kWh per day. Can better vacuum cleaners be designed?
Recently, Wallace Broecker, climate scientist, “perhaps the world’s foremost interpreter of the Earth’s operation as a biological, chemical, and physical system,” has been promoting an as yet unpublished technology developed by physicist Klaus Lackner for capturing CO2 from thin air. Broecker imagines that the world could carry on burning fossil fuels at much the same rate as it does now, and 60 million CO2-scrubbers (each the size of an up-ended shipping container) will vacuum up the CO2. What energy does Lackner’s process require? In June 2007 Lackner told me that his lab was achieving 1.3 kWh per kg, but since then they have developed a new process based on a resin that absorbs CO2 when dry and releases CO2 when moist. Lackner told me in June 2008 that, in a dry climate, the concentration cost has been reduced to about 0.18–0.37 kWh of low-grade heat per kg CO2. The compression cost is 0.11 kWh per kg. Thus Lackner’s total cost is 0.48 kWh or less per kg. For a European’s emissions of 30 kg CO2 per day, we are still talking about a cost of 14 kWh per day, of which 3.3 kWh per day would be electricity, and the rest heat.
Hurray for technical progress! But please don’t think that this is a small cost. We would require roughly a 20% increase in world energy production, just to run the vacuum cleaners.
Okay, this is me again: John Baez.
If you want to read about the other methods—trees, accelerated weathering of rocks, and ocean nourishment, go to McKay’s book. I’m not saying that they are less interesting! I am not trying, in this particular series of posts, to scan all technologies and find the best ones. I’m trying to study carbon dioxide scrubbers.
You need the word 'latex' right after the first dollar sign, and it needs a space after it. Double dollar signs don't work, and other limitations apply, some described here. You can't preview comments here, but I'm happy to fix errors.