John Harte

Earlier this week I gave a talk on the Mathematics of Planet Earth at the University of Southern California, and someone there recommended that I look into John Harte’s work on maximum entropy methods in ecology. He works at U.C. Berkeley.

I checked out his website and found that his goals resemble mine: save the planet and understand its ecosystems. He’s a lot further along than I am, since he comes from a long background in ecology while I’ve just recently blundered in from mathematical physics. I can’t really say what I think of his work since I’m just learning about it. But I thought I should point out its existence.

This free book is something a lot of people would find interesting:

• John and Mary Ellen Harte, Cool the Earth, Save the Economy: Solving the Climate Crisis Is EASY, 2008.

EASY? Well, it’s an acronym. Here’s the basic idea of the US-based plan described in this book:

Any proposed energy policy should include these two components:

Technical/Behavioral: What resources and technologies are to be used to supply energy? On the demand side, what technologies and lifestyle changes are being proposed to consumers?

Incentives/Economic Policy: How are the desired supply and demand options to be encouraged or forced? Here the options include taxes, subsidies, regulations, permits, research and development, and education.

And a successful energy policy should satisfy the AAA criteria:

Availability. The climate crisis will rapidly become costly to society if we do not take action expeditiously. We need to adopt now those technologies that are currently available, provided they meet the following two additional criteria:

Affordability. Because of the central role of energy in our society, its cost to consumers should not increase significantly. In fact, a successful energy policy could ultimately save consumers money.

Acceptability. All energy strategies have environmental, land use, and health and safety implications; these must be acceptable to the public. Moreover, while some interest groups will undoubtedly oppose any particular energy policy, political acceptability at a broad scale is necessary.

Our strategy for preventing climate catastrophe and achieving energy independence includes:

Energy Efficient Technology at home and at the workplace. Huge reductions in home energy use can be achieved with available technologies, including more efficient appliances such as refrigerators, water heaters, and light bulbs. Home retrofits and new home design features such as “smart” window coatings, lighter-colored roofs where there are hot summers, better home insulation, and passive solar designs can also reduce energy use. Together, energy efficiency in home and industry can save the U.S. up to approximately half of the energy currently consumed in those sectors, and at no net cost—just by making different choices. Sounds good, doesn’t it?

Automobile Fuel Efficiency. Phase in higher Corporate Average Fuel Economy (CAFE) standards for automobiles, SUVs and light trucks by requiring vehicles to go 35 miles per gallon of gas (mpg) by 2015, 45 mpg by 2020, and 60 mpg by 2030. This would rapidly wipe out our dependence on foreign oil and cut emissions from the vehicle sector by two-thirds. A combination of plug-in hybrid, lighter car body materials, re-design and other innovations could readily achieve these standards. This sounds good, too!

Solar and Wind Energy. Rooftop photovoltaic panels and solar water heating units should be phased in over the next 20 years, with the goal of solar installation on 75% of U.S. homes and commercial buildings by 2030. (Not all roofs receive sufficient sunlight to make solar panels practical for them.) Large wind farms, solar photovoltaic stations, and solar thermal stations should also be phased in so that by 2030, all U.S. electricity demand will be supplied by existing hydroelectric, existing and possibly some new nuclear, and, most importantly, new solar and wind units. This will require investment in expansion of the grid to bring the new supply to the demand, and in research and development to improve overnight storage systems. Achieving this goal would reduce our dependence on coal to practically zero. More good news!

You are part of the answer. Voting wisely for leaders who promote the first three components is one of the most important individual actions one can make. Other actions help, too. Just as molecules make up mountains, individual actions taken collectively have huge impacts. Improved driving skills, automobile maintenance, reusing and recycling, walking and biking, wearing sweaters in winter and light clothing in summer, installing timers on thermostats and insulating houses, carpooling, paying attention to energy efficiency labels on appliances, and many other simple practices and behaviors hugely influence energy consumption. A major education campaign, both in schools for youngsters and by the media for everyone, should be mounted to promote these consumer practices.

No part of EASY can be left out; all parts are closely integrated. Some parts might create much larger changes—for example, more efficient home appliances and automobiles—but all parts are essential. If, for example, we do not achieve the decrease in electricity demand that can be brought about with the E of EASY, then it is extremely doubtful that we could meet our electricity needs with the S of EASY.

It is equally urgent that once we start implementing the plan, we aggressively export it to other major emitting nations. We can reduce our own emissions all we want, but the planet will continue to warm if we can’t convince other major global emitters to reduce their emissions substantially, too.

What EASY will achieve. If no actions are taken to reduce carbon dioxide emissions, in the year 2030 the U.S. will be emitting about 2.2 billion tons of carbon in the form of carbon dioxide. This will be an increase of 25% from today’s emission rate of about 1.75 billion tons per year of carbon. By following the EASY plan, the U.S. share in a global effort to solve the climate crisis (that is, prevent catastrophic warming) will result in U.S emissions of only about 0.4 billion tons of carbon by 2030, which represents a little less than 25% of 2007 carbon dioxide emissions.128 Stated differently, the plan provides a way to eliminate 1.8 billion tons per year of carbon by that date.

We must act urgently: in the 14 months it took us to write this book, atmospheric CO2 levels rose by several billion tons of carbon, and more climatic consequences have been observed. Let’s assume that we conserve our forests and other natural carbon reservoirs at our current levels, as well as maintain our current nuclear and hydroelectric plants (or replace them with more solar and wind generators). Here’s what implementing EASY will achieve, as illustrated by Figure 3.1 on the next page.

Please check out this book and help me figure out if the numbers add up! I could also use help understanding his research, for example:

• John Harte, Maximum Entropy and Ecology: A Theory of Abundance, Distribution, and Energetics, Oxford University Press, Oxford, 2011.

The book is not free but the first chapter is.

This paper looks really interesting too:

• J. Harte, T. Zillio, E. Conlisk and A. B. Smith, Maximum entropy and the state-variable approach to macroecology, Ecology 89 (2008), 2700–-2711.

Again, it’s not freely available—tut tut. Ecologists should follow physicists and make their work free online; if you’re serious about saving the planet you should let everyone know what you’re doing! However, the abstract is visible to all, and of course I can use my academic superpowers to get ahold of the paper for myself:

Abstract: The biodiversity scaling metrics widely studied in macroecology include the species-area relationship (SAR), the scale-dependent species-abundance distribution (SAD), the distribution of masses or metabolic energies of individuals within and across species, the abundance-energy or abundance-mass relationship across species, and the species-level occupancy distributions across space. We propose a theoretical framework for predicting the scaling forms of these and other metrics based on the state-variable concept and an analytical method derived from information theory. In statistical physics, a method of inference based on information entropy results in a complete macro-scale description of classical thermodynamic systems in terms of the state variables volume, temperature, and number of molecules. In analogy, we take the state variables of an ecosystem to be its total area, the total number of species within any specified taxonomic group in that area, the total number of individuals across those species, and the summed metabolic energy rate for all those individuals. In terms solely of ratios of those state variables, and without invoking any specific ecological mechanisms, we show that realistic functional forms for the macroecological metrics listed above are inferred based on information entropy. The Fisher log series SAD emerges naturally from the theory. The SAR is predicted to have negative curvature on a log-log plot, but as the ratio of the number of species to the number of individuals decreases, the SAR becomes better and better approximated by a power law, with the predicted slope z in the range of 0.14-0.20. Using the 3/4 power mass-metabolism scaling relation to relate energy requirements and measured body sizes, the Damuth scaling rule relating mass and abundance is also predicted by the theory. We argue that the predicted forms of the macroecological metrics are in reasonable agreement with the patterns observed from plant census data across habitats and spatial scales. While this is encouraging, given the absence of adjustable fitting parameters in the theory, we further argue that even small discrepancies between data and predictions can help identify ecological mechanisms that influence macroecological patterns.

14 Responses to John Harte

  1. Michael Brazier says:

    That John Harte can say “Because of the central role of energy in our society, its cost to consumers should not increase significantly. In fact, a successful energy policy could ultimately save consumers money.”, and then recommend replacing fossil fuels with solar and wind, tells me that he does not know basic facts about the generation of electrical power. Specifically: At the industrial scale, electrical power has to be generated when it is needed; there are no practical means of storing power in the quantities industry requires. Therefore solar and wind power cannot supply power to a national grid – they create power when the sun shines or the wind blows, and we can’t control either of those. (Germany has borne this out in practice. They’ve been taking nuclear power plants offline and subsidizing solar and wind generators to replace them; because solar and wind are not reliable, this has forced them to use natural gas as a backup.) Resolving this problem requires basic research into high energy density batteries, and while such research is ongoing, it has not resulted in practical technology yet.

    Also, once the cost of manufacturing components is taken into account, both solar and wind are many times more expensive than any fossil fuel, even apart from the issue of reliability. Therefore, without large and perpetual government subsidy (which no government is in a position to offer, though some have tried) they won’t enter general use even for small applications that don’t require connecting to a national power grid. Resolving this problem requires basic research into photovoltaic materials and high-strength magnets, which is also ongoing. (Never mind the environmental side effects of manufacturing the components …)

    So to implement Harte’s program, we would first need the fruits of two separate major research programs which are at present years or decades from completion. Only after both programs were complete could we begin to make serious use of solar and wind energy. If Harte thinks we can finish all that in twenty years, he doesn’t understand the problem at all.

    The only method of power generation with a cost comparable to coal/oil/gas that doesn’t release carbon dioxide is nuclear fission. A massive expansion of nuclear power may relieve the need for fossil fuels; nothing short of that has a hope.

    • John Baez says:

      Yours is a viewpoint I’ve often heard and find quite plausible. What I’d like to do—or even better, get someone else to do—is look deeper into Harte’s book and see if he tries to address these issues, or merely sidesteps them.

    • You forgot about the large and perpetual government subsidy of nuclear power.

      Meanwhile here in Bavaria alone photovoltaic installations have outpaced the whole U.S. and at peak times replace the output of several nuclear power plants. German total record in May 2012 was 22GW peak, something like 15-20 nukes. I don’t think PV is more expensive than nukes, at least if you include the cost of nuclear waste disposal (E.g. cleanup of dilapidated German repository Asse is a few billions.)

      Problem is, grid construction hasn’t caught up. So, it will soon be necessary to occasionally switch off PV in order to not overload the grid. We have to give away overproduction to the Austrians, who convert it to pumped storage hydro power and later sell it back to Bavaria. It seems the German electricity companies haven’t yet noted the potential of pumped storage hydro.

      Now me as a potential customer: For my off-grid wilderness dream house, 2 solar panels and 2 standard car batteries would suffice. The laundry I would do in the city and for cooking and heating there’s wood. Most energy I would need for the stereo (250W). Luxury could be so cheap…

  2. Many countries have a good infrastructure for natural gas, with houses etc being hooked up to it as they are to power. Such an infrastructure can also handle hydrogen and other gases. Use non-steady power sources to create such gases by electrolysis or whatever, store them as gas and then just use them in gas-powered electrical generators in power plants or (especially if it is used for heating anyway) just use the gas directly.

    • Frederik De Roo says:

      Such an infrastructure can also handle hydrogen and other gases.

      As far as I know, this statement is not entirely correct. Although hydrogen piping is certainly possible, it’s more complicated to pipe hydrogen than natural gas. See e.g. Wikipedia, Hydrogen piping for some difficulties.

      • I recently read an article (in a paper magazine, hence no link, and anyway it was in German) on this, in a reputable magazine, which indicated that the problems were solvable and/or one could pipe a mixture of natural gas and hydrogen.

        • Frederik De Roo says:

          I don’t mind if the link is in German. So I’ve browsed a little bit and I found a link in a reputable German magazine.

          Viele Energieexperten glauben allerdings, dass die Energiewende mit der Umwandlung von Windenergie zu Wasserstoff allein nicht zu schaffen ist. Denn Wasserstoff kann nur in beschränkten Mengen ins Erdgasnetz eingespeist werden. Doch genau das wäre nötig, um die gespeicherte Ökoenergie flächendeckend einzusetzen.

          Die Umwandlung in Erdgas, also die Produktion von Methan aus Wasserstoff und Kohlendioxid, gilt daher als unumgänglich. Das Fraunhofer-Institut für Windenergie und Energiesystemtechnik will deshalb im kommenden Jahr in Stuttgart eine Pilotanlage in Betrieb nehmen, die aus Windkraft erst Wasserstoff und dann Methan erzeugt.

          As I understand it, the hydrogen would be converted to methane, and then piped through the net, because hydrogen by itself can only be inserted in very small quantities.

        • Makes sense. In any case, since natural gas is essentially methane, this would solve the problem the original comment mentioned about storing energy from non-constant sources.

          The article I was referring to was in the print magazine Bild der Wissenschaft. I think they have a web site, but I’ve never been there. (I subscribe and read it on paper in the train.)

        • Graham Jones says:

          Something similar can be done with methanol too.

        • Frederik De Roo says:

          Something similar can be done with methanol too.

          Yes, but because it’s a liquid I suppose it would rather replace oil than natural gas. By the way, you’ve reminded me that this page is actually still on an old ‘to do’ list of mine…

        • Interestingly, there was a report on German television this morning about using electricity from non-constant sources to make hydrogen via electrolysis and then combining this with carbon dioxide to make methane. Perhaps related to this is an article:

  3. • John Harte, Maximum Entropy and Ecology: A Theory of Abundance, Distribution, and Energetics, Oxford University Press, Oxford, 2011.

    The book seems quite a treasure. Something I’ve been waiting for. I had to hide it away for the next 2 weeks…

  4. I already talked about John Harte’s book on how to stop global warming. Since I’m trying to apply information theory and thermodynamics to ecology, I was also interested in his book on maximum entropy and ecology […]

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