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An open letter to Steve Levitt

Filed under: — raypierre @ 29 October 2009

Dear Mr. Levitt,

The problem of global warming is so big that solving it will require creative thinking from many disciplines. Economists have much to contribute to this effort, particularly with regard to the question of how various means of putting a price on carbon emissions may alter human behavior. Some of the lines of thinking in your first book, Freakonomics, could well have had a bearing on this issue, if brought to bear on the carbon emissions problem. I have very much enjoyed and benefited from the growing collaborations between Geosciences and the Economics department here at the University of Chicago, and had hoped someday to have the pleasure of making your acquaintance. It is more in disappointment than anger that I am writing to you now.

I am addressing this to you rather than your journalist-coauthor because one has become all too accustomed to tendentious screeds from media personalities (think Glenn Beck) with a reckless disregard for the truth. However, if it has come to pass that we can’t expect the William B. Ogden Distinguished Service Professor (and Clark Medalist to boot) at a top-rated department of a respected university to think clearly and honestly with numbers, we are indeed in a sad way.

By now there have been many detailed dissections of everything that is wrong with the treatment of climate in Superfreakonomics , but what has been lost amidst all that extensive discussion is how really simple it would have been to get this stuff right. The problem wasn’t necessarily that you talked to the wrong experts or talked to too few of them. The problem was that you failed to do the most elementary thinking needed to see if what they were saying (or what you thought they were saying) in fact made any sense. If you were stupid, it wouldn’t be so bad to have messed up such elementary reasoning, but I don’t by any means think you are stupid. That makes the failure to do the thinking all the more disappointing. I will take Nathan Myhrvold’s claim about solar cells, which you quoted prominently in your book, as an example.


As quoted by you, Mr. Myhrvold claimed, in effect, that it was pointless to try to solve global warming by building solar cells, because they are black and absorb all the solar energy that hits them, but convert only some 12% to electricity while radiating the rest as heat, warming the planet. Now, maybe you were dazzled by Mr Myhrvold’s brilliance, but don’t we try to teach our students to think for themselves? Let’s go through the arithmetic step by step and see how it comes out. It’s not hard.

Let’s do the thought experiment of building a solar array to generate the entire world’s present electricity consumption, and see what the extra absorption of sunlight by the array does to climate. First we need to find the electricity consumption. Just do a Google search on “World electricity consumption” and here you are:

GoogleElec

Now, that’s the total electric energy consumed during the year, and you can turn that into the rate of energy consumption (measured in Watts, just like the world was one big light bulb) by dividing kilowatt hours by the number of hours in a year, and multiplying by 1000 to convert kilowatts into watts. The answer is two trillion Watts, in round numbers. How much area of solar cells do you need to generate this? On average, about 200 Watts falls on each square meter of Earth’s surface, but you might preferentially put your cells in sunnier, clearer places, so let’s call it 250 Watts per square meter. With a 15% efficiency, which is middling for present technology the area you need is

2 trillion Watts/(.15 X 250. Watts per square meter)

or 53,333 square kilometers. That’s a square 231 kilometers on a side, or about the size of a single cell of a typical general circulation model grid box. If we put it on the globe, it looks like this:

Globe

So already you should be beginning to suspect that this is a pretty trivial part of the Earth’s surface, and maybe unlikely to have much of an effect on the overall absorbed sunlight. In fact, it’s only 0.01% of the Earth’s surface. The numbers I used to do this calculation can all be found in Wikipedia, or even in a good paperbound World Almanac.

But we should go further, and look at the actual amount of extra solar energy absorbed. As many reviewers of Superfreakonomics have noted, solar cells aren’t actually black, but that’s not the main issue. For the sake of argument, let’s just assume they absorb all the sunlight that falls on them. In my business, we call that “zero albedo” (i.e. zero reflectivity). As many commentators also noted, the albedo of real solar cells is no lower than materials like roofs that they are often placed on, so that solar cells don’t necessarily increase absorbed solar energy at all. Let’s ignore that, though. After all, you might want to put your solar cells in the desert, and you might try to cool the planet by painting your roof white. The albedo of desert sand can also be found easily by doing a Google search on “Albedo Sahara Desert,” for example. Here’s what you get:

GoogleSand

So, let’s say that sand has a 50% albedo. That means that each square meter of black solar cell absorbs an extra 125 Watts that otherwise would have been reflected by the sand (i.e. 50% of the 250 Watts per square meter of sunlight). Multiplying by the area of solar cell, we get 6.66 trillion Watts.

That 6.66 trillion Watts is the “waste heat” that is a byproduct of generating electricity by using solar cells. All means of generating electricity involve waste heat, and fossil fuels are not an exception. A typical coal-fired power plant only is around 33% efficient, so you would need to release 6 trillion Watts of heat to burn the coal to make our 2 trillion Watts of electricity. That makes the waste heat of solar cells vs. coal basically a wash, and we could stop right there, but let’s continue our exercise in thinking with numbers anyway.

Wherever it comes from, waste heat is not usually taken into account in global climate calculations for the simple reason that it is utterly trivial in comparison to the heat trapped by the carbon dioxide that is released when you burn fossil fuels to supply energy. For example, that 6 trillion Watts of waste heat from coal burning would amount to only 0.012 Watts per square meter of the Earth’s surface. Without even thinking very hard, you can realize that this is a tiny number compared to the heat-trapping effect of CO2. As a general point of reference, the extra heat trapped by CO2 at the point where you’ve burned enough coal to double the atmospheric CO2 concentration is about 4 Watts per square meter of the Earth’s surface — over 300 times the effect of the waste heat.

The “4 Watts per square meter” statistic gives us an easy point of reference because it is available from any number of easily accessible sources, such as the IPCC Technical Summary or David Archer’s basic textbook that came out of our “Global Warming for Poets” core course. Another simple way to grasp the insignificance of the waste heat effect is to turn it into a temperature change using the standard climate sensitivity of 1 degree C of warming for each 2 Watts per square meter of heat added to the energy budget of the planet (this sensitivity factor also being readily available from sources like the ones I just pointed out). That gives us a warming of 0.006 degrees C for the waste heat from coal burning, and much less for the incremental heat from switching to solar cells. It doesn’t take a lot of thinking to realize that this is a trivial number compared to the magnitude of warming expected from a doubling of CO2.

With just a little more calculation, it’s possible to do a more precise and informative comparison. For coal-fired generation,each kilowatt-hour produced results in emissions of about a quarter kilogram of carbon into the atmosphere in the form of carbon dioxide. For our 16.83 trillion kilowatt-hours of electricity produced each year, we then would emit 4.2 trillion kilograms of carbon, i.e. 4.2 gigatonnes each year. Unlike energy, carbon dioxide accumulates in the atmosphere, and builds up year after year. It is only slowly removed by absorption into the ocean, over hundreds to thousands of years. After a hundred years, 420 gigatonnes will have been emitted, and if half that remains in the atmosphere (remember, rough estimates suffice to make the point here) the atmospheric stock of CO2 carbon will increase by 210 gigatonnes, or 30% of the pre-industrial atmospheric stock of about 700 gigatonnes of carbon. To get the heat trapped by CO2 from that amount of increase, we need to reach all the way back into middle-school math and use the awesome tool of logarithms; the number is

(4 Watts per square meter) X log2(1.3)

or 1.5 Watts per square meter. In other words, by the time a hundred years have passed, the heat trapped each year from the CO2 emitted by using coal instead of solar energy to produce electricity is 125 times the effect of the fossil fuel waste heat. And remember that the incremental waste heat from switching to solar cells is even smaller than the fossil fuel waste heat. What’s more, because each passing year sees more CO2 accumulate in the atmosphere, the heat trapping by CO2 continues to go up, while the effect of the waste heat from the fossil fuels or solar cells needed to produce a given amount of electricity stays fixed. Another way of putting it is that the climate effect from the waste heat produced by any kind of power plant is a one-off thing that you incur when you build the plant, whereas the warming effect of the CO2 produced by fossil fuel plants continues to accumulate year after year. The warming effect of the CO2 is a legacy that will continue for many centuries after the coal has run out and the ruins of the power plant are moldering away.

Note that you don’t actually have to wait a hundred years to see the benefit of switching to solar cells. The same arithmetic shows that even at the end of the very first year of operation, the CO2 emissions prevented by the solar array would have trapped 0.017 Watts per square meter if released into the atmosphere. So, at the end of the first year you already come out ahead even if you neglect the waste heat that would have been emitted by burning fossil fuels instead.

So, the bottom line here is that the heat-trapping effect of CO2 is the 800-pound gorilla in climate change. In comparison, waste heat is a trivial contribution to global warming whether the waste heat comes from solar cells or from fossil fuels. Moreover, the incremental waste heat from switching from coal to solar is an even more trivial number, even if you allow for some improvement in the efficiency of coal-fired power plants and ignore any possible improvements in the efficiency of solar cells. So: trivial,trivial trivial. Simple, isn’t it?

By the way, the issue of whether waste heat is an important factor in global warming is one of the questions most commonly asked by students who are first learning about energy budgets and climate change. So, there are no shortage of places where you can learn about this sort of thing. For example, a simple Google search on the words “Global Warming Waste Heat” turns up several pages of accurate references explaining the issue in elementary terms for beginners. Including this article from Wikipedia:

WasteHeatWiki

A more substantive (though in the end almost equally trivial) issue is the carbon emitted in the course of manufacturing solar cells, but that is not the matter at hand here. The point here is that really simple arithmetic, which you could not be bothered to do, would have been enough to tell you that the claim that the blackness of solar cells makes solar energy pointless is complete and utter nonsense. I don’t think you would have accepted such laziness and sloppiness in a term paper from one of your students, so why do you accept it from yourself? What does the failure to do such basic thinking with numbers say about the extent to which anything you write can be trusted? How do you think it reflects on the profession of economics when a member of that profession — somebody who that profession seems to esteem highly — publicly and noisily shows that he cannot be bothered to do simple arithmetic and elementary background reading? Not even for a subject of such paramount importance as global warming.

And it’s not as if the “black solar cell” gaffe was the only bit of academic malpractice in your book: among other things, the presentation of aerosol geoengineering as a harmless and cheap quick fix for global warming ignored a great deal of accessible and readily available material on the severe risks involved, as Gavin noted in his recent post. The fault here is not that you dared to advocate geoengineering as a solution. There is a broad spectrum of opinion among scientists about the amount of aerosol geoengineering research that is justified, but very few scientists think of it as anything but a desperate last-ditch attempt, or at best a strategy to be used in extreme moderation as part of a basket of strategies dominated by emissions reductions. You owed it to your readers to present a fair picture of the consequences of geoengineering, but chose not to do so.

May I suggest that if you should happen to need some friendly help next time you take on the topic of climate change, or would like to have a chat about why aerosol geoengineering might not be a cure-all, or just need a critical but informed opponent to bounce ideas off of, you don’t have to go very far. For example…

GoogleMap

But given the way Superfreakonomics mangled Ken Caldeira’s rather nuanced views on geoengineering, let’s keep it off the record, eh?

Your colleague,

Raymond T. Pierrehumbert
Louis Block Professor in the Geophysical Sciences
The University of Chicago

807 Responses to “An open letter to Steve Levitt”

  1. 351
    Julia Isaak says:

    RE: rational/economic man
    Mark : If my brother was in harms way I would defend him. If a child were in danger, I (hope!) I would intervene.
    These do not rely on rational decision.
    They will be done. Now if I found my brother had deliberately put a child in danger, I may lay into him myself, but that’s not rationality: it’s compounding the irrationality.

    They are all examples of you as a rational actor, making judgments towards your subjectively defined ends. Hail, fellow homo economicus of the real world.

    But if we mean by ‘a rational man’, ‘a fully informed man’, as Brandt does…
    That is the straw rational man again, not a real-world one. Rationality does not require full information; you can rationally pursue your ends to the best of your ability making do with what incomplete information you do have.

  2. 352
    Patrick 027 says:

    Re tharanga re Mark – “in the absence of all subsidies. I really don’t see how you can argue that coal would cost 15-20 cents/kWh”

    I don’t know how far this would go in monetary costs, but what if the coal mining industry had to pay people off to destroy their homes rather than just come in like a thief (granted, that may not be so much a subsidy as it is yet one more in a litany of externalities, but…).

    I’ve also read something about fossil fuels getting tax breaks. There’s a problem with taxing fuel differently than solar panels (aside from externalities) – solar panels are economically like the fuel, if fuel is taxed differently than infrastructure, it seems fair that some components of fuel-less energy resources be taxed as if they were fuel, because I don’t see any inherent logic in fuel being taxed differently than any other thing (Actually that might be part of a much larger conundrum – what is a fair balance between property taxes, income taxes, sales taxes, etc.? Why should one be at higher or lower rates… etc. … I couldn’t begin to go into that mess – that might be a case where evolved behavior should be assumed to be not entirely wrong, but…).

  3. 353
    Steve says:

    Thanks for the comments on my #300.

    Sorry, but splitting the project into smaller portions only makes the return worse. You get more bang for your buck by doing the project in bulk. Ideally, a ground-up shopping center development with solar panels planned from day one would be the best return on costs.

    I have been able to get LEDs into our parking lot lights, though! I’ve only found one company that does it. They retrofit existing boxes, since manufacturers still aren’t cranking out pre-made LED parking lot lights. That project was a no brainer – payback is under 5 years. But our poor parking lot lighting service company lost our service contract – the lights won’t burn out for about 15 years!

    I’m working with guys who have been doing real estate development for over 30 years. They know all the angles, and right now there just isn’t a profit to be made in commercial solar installations for existing shopping centers. As soon as there is, you’ll start seeing them pop up everywhere. And if you don’t believe me, get your investors together, call a solar installation company and start making some money (i.e. put your money where your mouth is).

    It will happen eventually, just not yet. As long as there are other investments with a better return on costs, commercial solar installations are going to be at the bottom of the list.

  4. 354
    Julia Isaak says:

    From #316
    Gavin : there is a pretty good correlation between annual CO2 levels and temperatures over the last 150 years

    There is only a CO2-temperature correlation for 15 out of the last 130 (instrumental) years. For the other 115 years other (apparently not explained) factors dominate.
    Is 15/130 really “pretty good”?

    [Response: I have no idea why you think this or what this even means. Correlation is a property of the whole time series, not a subset of individual years within it. As shown at the link I gave you, there is a strong correlation over the last 150 years and it is at the same level that one would expect (given the internal variability and other forcings). What is your source for this bizarre 15 out of 130 years claim? – gavin]

    Gavin : the concern that exists on carbon emissions is not due to any such correlation…(it) is based on the physics of the problem not correlations
    If you want to argue CO2-induced AGW, you do have to take heed of correlation to back up your claim of getting an approximation of the overall climate physics right.

    [Response: But there is much more evidence that we have the overall physics right – the climatology, seasonality, response to volcanoes, responses to El Nino, paleo-climate tests, etc. etc. Temperatures have risen as they were predicted to do 30 or even 50 years ago and so the correlation now is supportive, but it was neither defining nor inspiring to the overall AGW theory (which has existed for far longer). Plus it should always be stressed that CO2 is not the only issue here (though it is the biggest component). – gavin]

    it has [] been ceaselessly drummed into citizens worldwide by virtually all politicians and media, that the science is settled, ie AGW is serious and needs massive political and physical action
    Gavin: AGW is serious and needs substantial action (in my opinion), but that is not predicated on ‘all science being settled’.

    I nowhere said it is widely claimed all the science is settled. It has though – and still is – constantly pushed that the science of ‘AGW being a serious problem’ is settled. But I take the point that there may well be serious be a breaks in the broad science->ipcc->journalism->politics->generalPublic information chain.

  5. 355
    Richard Steckis says:

    347
    Mike of Oz says:
    3 November 2009 at 10:26 PM

    “who says that we can’t possibly know anything about global temperatures more than 80 years ago because no-one measured them, and that all data prior to that is completely speculative rubbish.”

    I would suggest that if he is talking about GLOBAL temperatures, he is completely right. Whilst we have been measuring local temperature accurately for over 200 years, extrapolation to a global temperature is a relatively recent phenomenon.

    I do stand to be corrected if I am wrong.

  6. 356
    Anne van der Bom says:

    Julia Isaak,

    2 November 2009 at 4:35 PM

    Perhaps you should read into the theory of chaos and learn about the difference between state and behaviour. The Earth is a chaotic system (in the scientific sense of the word), and although it is (I’m inclined to say fundamentally) impossible to predict the state of such a system, still valid predictions can be made about its behaviour.

    Take a flag. Even if you put it in a wind tunnel with a perfect, steady, turbulenceless wind, it will sway back and forth in a chaotic fashion, it is absolutely impossible to predict the movements of the flag. However, we can observe that there is a clear relationship between the wind speed and the amplitude and frequency of the movements.

    That simplified system shows that if you can not predict state, it is possible to predict behaviour. And if you can only predict the behaviour of a flag and not its state, that doesn’t automatically disqualify it as a tool to see how the wind blows.

    The climate system is also full of those chaotic elements that make its state inherently unpredictable. But that doesn’t automatically mean we can not analyze and predict its behaviour with regards to influences like the increased amount of atmospheric CO2.

  7. 357
    Mark says:

    “Since New York City depends entirely on oil for it’s food supply as everyday trucks ship hundreds of tons of beef, … that source of global warming will always remain”

    Oh dear. So certain?

    Have you not heard of the 20th century answer: electric transport?

  8. 358
    Mark says:

    “Please stop misreading what I said. ”

    I’ll try.

    “You claimed that Britain had been involved in negotiations with Jordan (you thought) – this wasn’t true. I pointed out why.”

    Uh, no you didn’t. You said

    “Just one other thing, someone said that the UK government plans to buy solar energy from Jordan. I can’t see how – they’d need to build a helluva a lot of batteries to transport it.”

    This isn’t “this is not true, it’s europe and the sahara”.

    ” What’s so hard to accept?”

    What’s so hard to accept when I say “Uh, I don’t think they’ll use batteries, then.” when batteries have nothing to do with it and accepting this is right?

    If you don’t want me to misread what you write, don’t write what you apparently now meant to say “this is wrong” and instead write what you don’t mean “I can’t see how – they’d need to build a helluva a lot of batteries to transport it.”

    M’kay?

  9. 359
    Mark says:

    “Also, copyright/IP law is a matter of ownership. ”

    No it isn’t.

    You cannot own an idea.

    See your founding fathers discourse on this. It would show you how very wrong this is:

    “This violates freedom of choice no more than laws that prevent a person from parking their car on someone else’s lawn without permission without legal consequences.”

    Because I can take from you an idea and am enriched by it and you sill have the idea of which you first owned.

    It is more like telling people who bought their own lawn that they can’t park their car on it because someone patented that idea.

    [edit – please calm down]

  10. 360
    Mark says:

    “Back somewhat closer to the topic: Mark, despite all that verbiage, you have not supported your notion that coal would be as expensive or more expensive than solar,”

    IIRC Hank did that ages ago.

    California was what he used to show how much California pays per kWh for solar, wind, coal etc power since they have had appreciable amounts for long enough to get the initial inequalities out of the way.

  11. 361
    Mark says:

    PS Tharanga, I don’t see any proofs that renewables are more expensive than coal.

  12. 362
    Geoff Wexler says:

    #349

    It is quite common for busy and ambitious researchers to rely on the media for their knowledge of science outside their expertise.
    That applies independent of seniority.

  13. 363

    Jack Smith:

    Since New York City depends entirely on oil for it’s food supply as everyday trucks ship hundreds of tons of beef, and dairy products, and fruits and vegetables from the farm-belts in the Midwest and other parts of the world, that source of global warming will always remain. And it’s not a small amount either. Solar energy can’t do anything about it.

    The trucks could be powered with biodiesel or switch-grass or cane-sugar ethanol. They could be electric, in which case they could be charged from a grid powered by solar. And we could ship more in on rails, which would cut the energy requirements substantially. For that matter, I’d like to see dirigibles come back. Helium or steam to prevent explosions, solar cells on top, uplinks to weather data so they can be grounded when storms are coming.

  14. 364

    Julia,

    Here’s a study of the correlation between carbon dioxide and temperature:

    http://BartonPaulLevenson.com/Correlation.html

    Here are some studies which conclude that the Medieval Warm Period was NOT warmer than today:

    Bradley, R.S., Hughes, M.K., and H.F. Diaz 2003. “Climate Change in Medieval Time.” Science 302, 404-405.

    Goosse H., Arzel O., Luterbacher J., Mann M.E., Renssen H., Riedwyl N., Timmermann A., Xoplaki E., Wanner H. 2006. “The Origin of the European ‘Medieval Warm Period’.” Clim. Past, 2, 99–113.

    Osborn, Timothy J. and Keith R. Briffa 2006. “The Spatial Extent of 20th-Century Warmth in the Context of the Past 1200 Years.” Science 311, 841-844.

  15. 365
    Mark says:

    Skecsis: “I would suggest that if he is talking about GLOBAL temperatures, he is completely right. Whilst we have been measuring local temperature accurately for over 200 years, extrapolation to a global temperature is a relatively recent phenomenon.”

    Nope, it’s quite an old theory:

    http://en.wikipedia.org/wiki/Sample_(statistics)
    http://en.wikipedia.org/wiki/Estimation_theory

    Take lots of scattered measurements and work out what real average could give you the same sample average.

    This requires that even if your measurements have no error that you have error bars because many different real averages could give the same sample average. This may be why denialists have problems: they never use error bars and don’t seem to understand them.

  16. 366
    Mark says:

    “Sorry, but splitting the project into smaller portions only makes the return worse. You get more bang for your buck by doing the project in bulk. Ideally, a ground-up shopping center development with solar panels planned from day one would be the best return on costs.”

    But only if you are really doing the smaller portions serially and contiguously, thereby wiring up solar panels until they can be connected and moving then on to more panels.

    I note that you haven’t answered whether you need all that roof space covered.

  17. 367
    Mark says:

    “They know all the angles, and right now there just isn’t a profit to be made in commercial solar installations for existing shopping centers.”

    Then they aren’t up to speed.

    1) I genuinely do not think 2 million is required
    2) I genuinely don’t think 10 years is the ROI (other current systems get payback in 5)
    3) I genuinely do not think you must convert the entire rooftop (which is why #1 even if the roof conversion would cost 2mil)
    4) You can still paint the roofs white: i.e. who says you have to install PV?

  18. 368
    Mark says:

    Julia: “That is the straw rational man again, not a real-world one. Rationality does not require full”

    Indeed. Therefore the rational man of economic theory doesn’t exist. As Lynne said and you and Rene demand is not so while concurrently saying it doesn’t exist.

    You and Rene seem to be arguing that since rational man as defined cannot exist then rational man does exist because that definition cannot exist.

    A contortion of illogic that is impossible to penetrate.

    “That’s a strawman” is not correct. Rational Man must be fully informed and have free choice is part of the definition of rational man. What you want is Not Rational Man. Who isn’t Rational Man because Rational Man cannot exist.

    Well, the man you keep calling rational isn’t Rational Man.

    Analogy time:

    Infinity cannot exist as a number. You and Rene would therefore define infinity as a million billion. When told this isn’t infinity because there’s the next countable number one million billion and one, you say “no! your infinity is a strawman because it doesn’t exist! whereas a million billion does, so that is infinity!”.

    Rational Man is defined. That that definition doesn’t exist doesn’t mean you get to unilaterally redefine it.

  19. 369
    Anne van der Bom says:

    Julia Isaak

    You said:

    It has though – and still is – constantly pushed that the science of ‘AGW being a serious problem’ is settled.

    Risks are a problem. The non-negligeability of those risks are settled i.m.h.o.

  20. 370
    Rene says:

    Everyone here seems to bristle at the term ’skeptic’, but still noone will offer an alternative word for : someone who questions or doubts whether AGW is a serious problem.

  21. 371
    Steve says:

    I note that you haven’t answered whether you need all that roof space covered.

    Read my original post #300. Specifically about the solar panels going in the parking lot. I need zero roof space covered.

    But only if you are really doing the smaller portions serially and contiguously…

    There are major startup costs that only have to be expensed once. Design, permit approval and installation of the new electrical systems themselves that the solar panels will tie into (you can’t just plug them into an outlet in the wall). Doing all that and then installing fewer panels makes the return worse, not better.

    #367… OK, think what you want. Like I said, put your money where your mouth is if you don’t believe me – apparently you’re gonna make a fortune selling solar panel installations to shopping centers. And are you really going to suggest “painting the roof white” is comparable to a solar panel array that generates electricity? A white roof doesn’t cut a shopping center’s electric bill by any appreciable amount. It does make the roof last longer! (less UV deterioration over decades, longer roof life, fewer leaks during that lifetime) And just so’s you know, you don’t “paint the roof white”, you purchase a white roofing system to replace your current roof waterproofing. Paint wouldn’t last more than 5 years on a shopping center roof, and all the while your roof runoff would be putting paint chips into the city’s storm drains. I’m not even sure that’s legal.

  22. 372
    Mark says:

    “And are you really going to suggest “painting the roof white” is comparable to a solar panel array that generates electricity?”

    No I’m not and never had.

    But painting them white will, especially in California, save so much on cooling bills whilst ALSO reducing the amount of solar radiation thermalised (not much, but every little helps) that you should see enough improvements in your bottom line to make this go.

    Who has said you HAVE to make PV?

    All you have to do is better.

  23. 373
    Mark says:

    PS: “Paint wouldn’t last more than 5 years on a shopping center roof,”

    You know, with the savings on reduced energy bill, you could, oh, PAY someone (and taking a few people off the welfare state, turning them into generators of wealth rather than sinks) to clean and repaint your roofs.

    And after that STILL end up better off financially and with the lowered CO2 burden helping the state reach its target reductions.

  24. 374
    Mark says:

    “someone who questions or doubts whether AGW is a serious problem.”

    Yes, it’s denier.

    Your position isn’t “skeptic” it’s “directed credulous”. Easily willing to doubt that AGW is wrong but unwilling to doubt that proposition is false.

    And in addition in this case, denying that there’s anything needing to be done, since you aren’t convinced.

    Denier.

  25. 375
    tharanga says:

    Mark:

    “PS Tharanga, I don’t see any proofs that renewables are more expensive than coal”

    Are you serious? That’s the basis of all discussion on the topic. Production costs are around 3-4 cents/kWh for coal; a bit more than that for wind, depending on where you are, and anywhere from 10-30 cents/kWh for solar. Nuclear is a bit of an unknown, until somebody completes a new plant. These differences aren’t due to production subsidies; they are the inherent production costs.

    If you add in a carbon price, then coal loses its edge.

  26. 376
    Hank Roberts says:

    Rene, as to definitions — there are lumpers, splitters, and stirrers.
    You’re just stirring. Please do something useful. Like finding out where Julia is getting her ideas, since she’s been asked repeatedly and been unable to answer where she gets them. Can you find her source?

  27. 377
    Jack Roesler says:

    Granted this is off-topic, but here’s one that just showed up on another blog, by a serial AGW denier. I must admit, that if this is an official NOAA temperature measuring station, it’s a boon to the deniers.

    http://wattsupwiththat.com/2008/11/20/how-not-to -measure-temperature-part-75/

    You’ll have to close the gap in the URL.

  28. 378
    Mark says:

    “Are you serious? That’s the basis of all discussion on the topic. Production costs are around 3-4 cents/kWh for coal; a bit more than that for wind, depending on where you are, and anywhere from 10-30 cents/kWh ”

    You’ve never put those figures down before.

    So it’s hardly fair to say “Are you serious?” because the answer is “yes. why wouldn’t I be?”.

    Here are California’s figures which disagree completely with your coal figures:

    http://www.sourcewatch.org/index.php?title=Comparative_electrical_generation_costs

    I suspect this is where Hank got them from.

    Lazard analysis (which seems to include the cost for creating the generating capacity) are:

    * Gas peaking: 22.1 – 33.4
    * IGCC: 10.4 – 13.4
    * Nuclear: 9.8 – 12.6
    * Advanced supercritical coal: 7.4 – 13.5 (high end includes 90% carbon capture and storage)
    * Gas combined cycle: 7.3 – 10.0

    * Solar PV (crystalline): 10.9 – 15.4
    * Fuel cell: 11.5 – 12.5
    * Solar PV (thin film): 9.6 – 12.4
    * Solar thermal: 9.0 – 14.5 (low end is solar tower; high end is solar trough)
    * Biomass direct: 5.0 – 9.4
    * Landfill gas: 5.0 – 8.1
    * Wind: 4.4 – 9.1
    * Geothermal: 4.2 – 6.9
    * Biomass cofiring: 0.3 – 3.7
    * Energy efficiency: 0.0 – 5.0

    prices in cents per kWh.

    Just bus-generation (a generator equivalent of Brake Horsepower)

    * Coal Supercritical: 10.554

    * Biogas: 8.552
    * Wind: 8.910
    * Concentrating solar thermal (CSP): 12.653

    * Nuclear: 15.31

    again c/kWh.

    “Production costs are around 3-4 cents/kWh for coal;”?

  29. 379
    Richard Steckis says:

    365
    Mark the lip says:
    4 November 2009 at 8:58 AM

    “Nope, it’s quite an old theory:”

    Wrong, wrong wrong. I know what averaging is. Please don’t be facetious. The fact is that average global temperature values have only been used in climate science relatively recently. The global climate data sets we use (e.g. GISS, HadCRUT, NOAA) have only been available for about three decades.

  30. 380
    Richard Steckis says:

    By the way Mrk,

    We were discussing available datasets not statistical methodology.

  31. 381
    Hank Roberts says:

    > I suspect this is where Hank got them from.

    Mark, you’ve started to pepper your postings with references to me that lack any basis, and I don’t have time to clean up after this kind of thing. Nor to look things up for you. Please stop. Look things up for yourself, don’t handwave and then attribute to someone else. It’s an imposition.

    Get well soon.

  32. 382
    KevinM says:

    Re: Mark 377

    * Gas peaking: 22.1 – 33.4
    * IGCC: 10.4 – 13.4
    * Nuclear: 9.8 – 12.6
    * Advanced supercritical coal: 7.4 – 13.5
    * Gas combined cycle: 7.3 – 10.0
    * Solar PV (crystalline): 10.9 – 15.4
    * Fuel cell: 11.5 – 12.5
    * Solar PV (thin film): 9.6 – 12.4
    * Solar thermal: 9.0 – 14.5
    * Biomass direct: 5.0 – 9.4
    * Landfill gas: 5.0 – 8.1
    * Wind: 4.4 – 9.1
    * Geothermal: 4.2 – 6.9
    * Biomass cofiring: 0.3 – 3.7
    * Energy efficiency: 0.0 – 5.0

    There’s my friend nuclear again. The cheapest way to produce huge amounts of energy without the carbon. None of the less expensive options on the list can be added as readily.

    By that subjective statement I mean miles of for wind farms, or herds of cattle on miles of land for biomass, or miles of rooftops for solar. Works in rain or sunshine, windy or still.

    The list does indeed include the cost for creating the generating capacity. The Shearon Harris plant near where I live has a marginal cost of 3-4.

  33. 383
  34. 384
    Hank Roberts says:

    Julia, trying to figure out your source; are you relying on one of these?

    CO2 – Temperature Correlation The temperature of the Earth has warmed slightly, …. northern hemisphere temperature during the past 130 years. …
    http://www.friendsofscience.org/…/Climate_Change_Science.html

    The CO2-temperature correlation works well for the last 30 years or so, …
    http://www.swamppolitics.com/…/but_could_gore_win_tennessee.html

  35. 385
    Mark says:

    “There’s my friend nuclear again. The cheapest way to produce huge amounts of energy without the carbon.”

    except for these:

    * Energy efficiency: 0.0 – 5.0
    * Biomass cofiring: 0.3 – 3.7
    * Geothermal: 4.2 – 6.9
    * Landfill gas: 5.0 – 8.1
    * Biomass direct: 5.0 – 9.4
    * Wind: 4.4 – 9.1
    * Gas combined cycle: 7.3 – 10.0
    * Solar PV (thin film): 9.6 – 12.4

    “None of the less expensive options on the list can be added as readily”

    Uh, definitely wrong in the case of:

    * Energy efficiency: 0.0 – 5.0
    * Landfill gas: 5.0 – 8.1
    * Wind: 4.4 – 9.1

    But extremely unlikey to be true of any the others in the above list.

  36. 386
    Mark says:

    “Get well soon.”

    It’s only a cold, but a bad one.

    Worse emotionally are the ones where you’re sneezing and icky. DON’T go to work because you won’t be 100% and you’ll pass it on to lots of others unnecessarily.

    But because you’re not at work, you feel (or I do) that you can’t go out to the shops or do the garden because

    1) you’re sick. That’s why you’re off work. Ergo you should not strain yourself and slow the healing process

    2) How can you tell you’re not malingering and making it up because you’re sick of work? Self deception is the hardest thing to spot.

    So with a worse cold I’m sitting about bored out of my skull because to do something with my time off seems wrong.

    At least this time I spent all of sunday in bed sweating this out.

    Ta.

  37. 387
    Robert says:

    Well, the good professor Pierrehumbert has a little error of his own. You need to at least double the land area, since the sun doesn’t shine 24 hours a day. But don’t worry, I won’t get sarcastic with you as you did in this post.

    [Response: Already included in the 250 W/m2 number. Daytime averages would be twice that. – gavin]

    [edit]

    Regards,

    Robert

  38. 388
    Chris Colose says:

    Julia Isaak,

    I am having a difficult time following your logic. In particular, I am having a hard time following the whole “15 out of 150 years” argument, because it makes no sense. As gavin noted, correlation is a property of the whole time series.

    Now you can break up a 150 year time interval into small sub-intervals and run a correlation on each one between some explanatory variable and some response variable (in this case CO2 and temperature). If we do this, your claim sounds like you achieve an r^2 value of something greater than zero during one of these 15 year intervals and an r^2 value of exactly zero during all other sub-intervals. This is of course wrong. However, I cannot think of any other way to interpret your argument.

    Finally, for whatever reason, you insist on thinking that temperature rises as a function of CO2 alone. Instead, we know that dT = dT(log CO2, TSI, aerosols, CH4, volcanoes, …) plus the fact that the system has a non-zero amount of “noise.” You also have to figure that measurements of global temperature are imperfect. This involves a multiple regression problem if you’re only interested in correlation, and if you do that, you’ll find CO2 is the dominant explanatory variable. This is not why the modern temperature rise is actually formally attributed to CO2, but it’s something to chew on.

    Finally, you’ll note that models do a very good job of simulating the time-evolution of the 20th century temperature trend when you include all forcings. See Figure 2 in Meehl et al 2004 for example of how models fail to simulate the observed warming without anthropogenic influence. This is also not how formal attribution is done, but it’s at least a good test.

  39. 389
    KevinM says:

    Mark,

    You are arguing on every single thread in this commentary: persistently, shrilly and ineffectively.

    You skipped the part where I qualified.

    “By that subjective statement I mean miles of for wind farms, or herds of cattle on miles of land for biomass, or miles of rooftops for solar. Works in rain or sunshine, windy or still.”

    Like all other people you correspond with to here, I’ve now degenerated to reposting statements and arguing on context instead of content.
    [edit]

  40. 390
    Lynn Vincentnathan says:

    Steve, #300, I sure do hope it all comes together soon (cost down, etc) to install solar panels sort of as carports in the parking lot. I saw some scheme years ago before Calif (and the powers that be) killed the EV, of using those solar carport parking lots to power EVs. So that’s a fourth thing — keep a few choice slots, very close to the stores, to sell the electricity directly to the EV owners at a higher rate than the utilities will give.

    The future looks a bit brighter already!

  41. 391
    Jim Eager says:

    Re Jack Smith @345: “Solar energy can’t do anything about [transport]”

    False assertion. Solar and other non-fossil fuel-based electrical generation can be used to 1) charge electrically powered highway transport, and 2) electrically powered rail transport. The latter is hardly a new idea, seeing as the Washington DC-Boston rail corridor was electrified for much of the 20th century.

    “only petrochemical based farming can produce the high yields needed to feed the growing number of urban dwellers”

    You might want to check on the veracity of that statement as well.

  42. 392
    Mark says:

    I realised Kevin (388) which is why I went on to show how they were really quite silly reasons.

    If after evviciency reductions and lifestyle change reductions we had about enough nuclear capacity to supply the remaining needs, then I would be more “how about improving the effectiveness of current nuclear power” rather than “make wind farms”. Mostly because in that scenario wind farms would be an unnecessary expense.

    Do you think the US will manage such a huge cut in energy needs?

    I don’t think France could. Even though they are less energy intensive and have a large proportion of energy already nuclear supplied.

  43. 393
    Mark says:

    PS Kevin, how do you have to build out miles of cattle to bring energy efficiency benefits?

    landfills just need building to exploit, just as you would demand nuclear power stations need to be built (you can’t just pop more U238 into an existing reactor and hope to get more kW’s out).

  44. 394
    Lynn Vincentnathan says:

    #383, Hank, yep.

  45. 395
    gavin says:

    To all commenters: I am getting tired of editing out unsubstantive playground shouting matches. If you want to post on substantive points, ask for clarification of ambiguous statements or argue based on actual evidence, go ahead. But we’ve had enough of people simply sniping at other people and the tit for tat noise that provokes. Please stop. Note this is not up for discussion.

  46. 396
    tharanga says:

    Mark, 378
    “You’ve never put those figures down before.”

    Because they’re so commonly repeated. I didn’t think anybody didn’t realise coal was dirt cheap, besides being dirty.

    First off, you misrepresented what the Lazard numbers are (I suggest you get the original document). They don’t exclude subsidies; they specifically say they include them, which is what brings their solar costs down. Exclude subsidies, and the renewables shift back up.

    I’ll allow that 3-4 cents per kWh would be for an old-style, dirty coal plant, like what a developing country might build. Those costs probably also reflect previous, lower prices of steel and other building materials; sorry about that. Various sources give anywhere from 5 to 7 cents for a new, modern supercritical pulverized coal plant. (Here’s an analysis for a specific project at 6.3 cents http://www.netl.doe.gov/energy-analyses/pubs/deskreference/B_PC_SUP_051507.pdf)

    Lazard comes in at the high end of that, starting at 7.8 cents. I don’t know why their numbers are higher than others. The Lazard range goes up to 14.4 cents/kWh, but that includes the cost of capturing and compressing 90% of the CO2. The latter price actually sounds too low to me.

    What’s getting lost in the mix is also the substantial cuts in carbon emissions and other pollutants that can be had by switching from coal to natural gas, while other alternatives are being scaled up.

  47. 397
    Martin Vermeer says:

    Rene #370: ‘suckers‘?

  48. 398
    Mark says:

    “Mark, 378
    “You’ve never put those figures down before.”

    Because they’re so commonly repeated. I didn’t think anybody didn’t realise coal was dirt cheap, besides being dirty.”

    OK, but why are they so different?

    3-4c/kWh is far FAR lower than the figures for california. And I really don’t buy the explanation that it’s dirty coal that is so cheap. I would propose it is more likely that that 3-4c/kWh isn’t the busbar-generation so your 40% efficiency means 2.5x 3-4 c/kWh. That would make it 7.5-10c/kWh which is much more in accord and a much simpler explanation.

    And using the one report to cross-compare seems a much sounder method than comparing different reports separately. As the link says, coal expense has been elsewhere predicated on coal costing $6000/ton where 8+ is a better result (and note: prices are higher yet whilst PV has gone down) another reason to use the same report.

    Which makes wind cheaper, solar and coal about the same (but see above on the cost of raw materials).

    And even greater cuts in carbon emissions would be realised by using tide, wind or solar as opposed to gas.

    “They don’t exclude subsidies; they specifically say they include them, which is what brings their solar costs down. Exclude subsidies, and the renewables shift back up.”

    They don’t include tax benefits as George H proposes as an unequal difference.

    And again I do not think you should work that way with subsidies. Most of the subsidies are to reduce the setup costs or investigating new methods of capture. This doesn’t go to underwriting the cost of solar or wind.

  49. 399
    tharanga says:

    to Gavin, or anybody else (off topic):

    Any thoughts on how the new Smos satellite will increase understanding of the water cycle, as it relates to climate modeling?

  50. 400
    Chris Dudley says:

    Here we are. This is what Levitt is after: “If nothing else, getting an economics Ph.D. should teach someone how to complicate and obfuscate the issue so that it isn’t so obvious to outsiders that the argument makes no sense.” http://freakonomics.blogs.nytimes.com/2009/11/04/guess-what-the-initials-nada-stand-for/

    That is what he learned in economics school I guess. Now he needs to learn the corollary: If you have an economics Ph.D., don’t try to complicate and obfuscate if you are the outside since everyone will know you make no sense.