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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:


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:


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:


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:


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…


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. 701

    Jim, I read your post just before bed last night, which I suppose explains why I awoke thinking about the idea that the “SO2 solution” could possibly accomplished at a cost of “something like 20, 50 million.”

    Let’s see–

    The stratosphere is considered to begin at about 8 km in the polar regions. The tallest chimney in the world, according to Wiki, is the GRES-2 stack in Kazakhstan at 419.7 meters tall. But Wiki doesn’t give construction costs, so let’s consider the #2 chimney, Inco’s “Superstack” in Sudbury, Ontario, at 380 meters. So, we are talking about a structure roughly 2.5 x 8 = 20 times taller than anything comparable.

    Wiki says the estimated cost in 1972 was $25 million. Using the per capita GDP measure of inflation, that would be about 19 times greater in 2006 dollars, which already gets us to about $500 million. Using the 20 times taller naively, as a multiplier (I’m guessing the increase would be more nearly exponential, as this type of scaling is highly unlikely to be linear!) we get $10 billion.

    Oh, yes, the proposal was to build two of them, so we can’t forget to multiply by two–that’s $20 billion.

    And I suppose one would need to consider that these construction projects would be taking place in the most inhospitable environments in the world–there’s only a three-month yearly work window in Antarctica? That the North Pole stack would be placed in the middle of an ocean–depth at that location 4087 meters–so we’re talking about the world’s deepest footings, too? Any guesses how these facts would multiply the cost?

    Then there’s the question of actually operating the thing. Where does the SO2 come from–is it produced on-site somehow? If so, where do the raw materials come from? What about support–is a permanent human presence for maintenance implied? And just how is this incredible machinery going to be powered? Since Levitt and Duner are economists, what about financing costs–where is the capital going to come from, and how much is it going to cost?

    At this point, my intuition is that we could well be into the range of many trillions of dollars to actually do this “relatively cheap” geoengineering scheme, which means it’s roughly comparable to mitigation, according to L & D. And unlike mitigation, the cost is actually unbounded since the thing could need to operate basically in perpetuity.

    It might not be technically doable at any price with current technology–an 8+ km tower built anywhere would certainly be the foremost wonder of the world today. It’s also hard to imagine that it could be done on less than decadal timescales even if it is feasible.

    You’re right if you call all this “back-of-envelope”, or maybe even hand-waving, but I do think that I’ve given the idea more serious thought in the last 45 minutes than Levitt and Dubner ever did before they went to print with it. And some of that thought is in their area of expertise!

    Incredibly shoddy. You have to believe they just didn’t try very hard.

  2. 702

    Just a slight follow-on to the previous post: the FY2010 budget request for “Antarctic Infrastructure and Logistics” is “nearly a quarter of a billion dollars.”

    BTW, the story of the Inco superstack, linked in the previous post, is an environmental story well-worth perusing just from a general interest viewpoint if you don’t already know it.

  3. 703

    Jesse, you are so right about the impact of WWII on aviation, as well as your remarks about the railroads and suburbia. But don’t forget WWI. (Cf. the 2,000-pound bomb payload of the Handley-Page Type 0/400 bomber, which was operational not quite 15 years after the Wrights’ first flight at Kitty Hawk.)

    See here, section “The Growth of Military Aviation.”

  4. 704
    Rod B says:

    Jim Bullis (697), et al

    T. Boone Pickins’ north Texas wind farm is a clear example of what you say. He would not have started it without a solid belief that at a minimum the federal production subsidy would be maintained. He was totally open about this. Plus he was counting on (hoping for?) increased profitability of his natural gas as a fall out for his wind farm, a subsidy of sorts . He was also counting on others to provide (pay for) the transmission requirements.

    Yout integrated circuit analogy is less than perfect. The scaling of more densely packed chips (which is the prime metric of advancement) is greatly dependent of the chip making machines (AMD, e.g.) which get exponentially larger and more costly as the density (actually circuit channel widths) improves.

  5. 705
    Rod B says:

    BPL, I can apply a precise force of 1.056 newtons against a mass of 1.111 kg and, with knowledge of the resistance force within 4 significant digits (doable) I can easily, accurately and precisely predict the mass’ acceleration within 4 significant numbers. No one can accurately predict Price within even the same ballpark using MV/Q = P other than in the unreal ethereal theoretical. In fact the only thing (input or output) that can be even halfway accurately determined is M.

  6. 706
    Jim Galasyn says:

    Fyi, I reiterated my objection to WUWT and CA nominations for Best Science Blog on the Weblog Awards forum:

    Please remove anti-science blogs from the Best Science Blog category

    Repeating my plea from the nomination thread ( Please remove anti-science blogs “Watts Up with That” and “Climate Audit” from the Science category. The brand of contrarianism on display at both blogs fits no legitimate definition of “‘science.”

    The editorial position at both blogs is that human carbon emissions do not change Earth’s radiative balance with space, and that a conspiracy of corrupt scientists has made up the story for cryptic purposes.

    To illustrate just how unscientific both blogs are, consider the remarkable unanimity of the legitimate scientific community on the issue:

    “With the release of the revised statement by the American Association of Petroleum Geologists in 2007, no remaining scientific body of national or international standing is known to reject the basic findings of human influence on recent climate change.” (

    As for the “evil climate scientist” theory, I’ll leave it to the Weblog Awards editors to assess its credibility.

    The Best Humor Blog category would be the appropriate place for “Watts Up with That” and “Climate Audit.”

  7. 707
    Rod B says:

    Jesse (700), your main point, IMO, is quite deserving. But your supporting examples completely mischaracterized, bastardized, and dumbed-down “subsidies.” Car manufacturers were not successful because the government built roads. The government built roads because the people buying cars (btw, because cars were much neater and more convenient and desirable than horses and carts — not because Ford et al had a good advertising agency) wanted to use them more and wanted to drive on something other than dirt sometimes. The roads also happened to support the society as a whole with greatly improved distribution of farm products and other goods and services, not to mention the mobility of military defense forces. Were the trails through the Rockies built to subsidize the covered wagon industry?? Building roads to subsidize the auto industry is down there at about number 217. Your suggestion that iPod owes its success to an advertising agency that is magnitudes better than Sony’s begs credibility. Etc. Etc. Etc. (Though some do have merit, e.g., railroads, et al, and to some extent early coal mining. However the latter example is partly a matter of definition (discussed in RC before): I think that not charging some added expense or tax to an industry is not the same as giving them a subsidy — though others here will disagree with that.)

    Still, your main point deserves some consideration.

  8. 708
    Deech56 says:

    Jim G. Un-nomination seconded.

  9. 709
    Jim Galasyn says:

    Thanks, Deech. Has anybody actually tried this before? The Weblog Award editors might be reasonable folk…

  10. 710
    Po says:

    Rob B 707,

    Actually Rob, Jesse was right, the covered wagon industry was subsidized, big time. The Butterfield Overland Mail was the first transcontinetal commercial overland transportation system. It returned something like 1% of the money the government paid for the for its first 6 year contract for carrying the bi-weekly mail. I won’t bore you with the fact we are really talking stagecoaches and not covered wagons but you get my point. If you want to do something really great and difficult, you very well may need the government to subsidize it. The invisible hand of the economy is like the emperor’s clothes. Until some little Jesse points out the clarity of what is missing.

  11. 711
    Ric Merritt says:

    Jim Bullis, # 698, says

    “Of course when wind power generating capacity offers a standby reserve capability, every thing I say about electric cars changes.

    The problem with getting there is that wind power has to first displace all the operating coal generators, which is theoretically possible, but hard to see happening in many decades. After that some additional capacity has to be constructed; and then you will get renewable energy when you plug in your car. Not before.”

    You have been making similar points, using many thousands of words, in dozens or hundreds of places on several forums for a long time, and I am getting impatient with your logic, much as I congratulate you on your perseverence in the crucial field we may loosely call sustainable development. (I’m not saying your car won’t “fly”, and if it does you have all my good wishes.)

    My quote from you is about “wind power” but, as you no doubt agree, the important questions are really about the mix of all power sources. So let’s phrase it in terms of green power generally, defining green as not creating dangerous anthropogenic interference in the climate.

    The big question has to be along the lines of migrating (slowly, perforce, but fast enough to matter) from mostly dirty power to mostly or all green power. Obviously, if we get far along that path, to the point when the amount of dirty power is much less and the climate is responding to our efforts, we’ve made wonderful progress. I fail to see the relevance of what happens at the margin when one particular plug-in owner plugs in. That’s not the important question. The important questions are about the mix of power sources over many decades and the interaction of various technologies, consumer demands, and hoped-for conservation and efficiency efforts during that time.

    If my memory of your numerous postings is correct, you typically end with a resounding rejection of the possibility that plug-ins could ever do any good. But that conclusion does not follow from narrow facts about which power source is dispatchable (in what quantities?!) at a given time in history.

    Since I am recalling a mix of many postings over a long time, possibly I’ve been unfair to your train of thought in context. Feel free to set me straight, but please connect the narrower premises to the larger questions, considered over a span of decades, and gracefully acknowledge uncertainties in postulates and quantifications.

  12. 712

    700 Jusse,

    Absolutely right!

    Well, actually some railroads builders got massive land grants, some were a mile wide, every other mile on each side of the tracks they laid. And we all benefit from land stolen.

    My argument is not whether we should do subsidies but whether we should analyze the cost correctly and be open about it. And some might have a good effect and some might not. And in the end, some of the right actions will simply not happen because of the cost.

    It is discouraging to my point of view (see to see energy guzzling cars being equipped to run on coal fired electricity. But this is happening with massive government support. I fail to be persuasive against this since this will shift from oil to coal as the fuel source. The “smart” grid is said to be a way of bringing renewables to where their output can be used; true, but it will mostly be a way to perpetuate and encourage coal fired power plants.

    Under the situation emerging, there is no reason for people to give up the kind of cars they love. All people have to do is plug in at night and they will be set for many years to come. Thus I am reluctantly coming to the conclusion that a lot of effort trying to get people into a different kind of car is wasted. If we banned coal, I think there would be a mad scramble for my kind of solutions.

    I think there will have to be acceptable low cost alternatives to the kind of cars we now use that do not depend on coal fired electricity before there will be any real political will to limit coal use.

    The annoying thing is that we have government acting to set us up to depend on coal by encouraging plug-in cars and long distance power transmission, while heading to a Copehagen conference to argue against CO2 emissions.

  13. 713

    711 Ric Merrit

    I am glad that some of my words have been read. Disconnected? Probably guilty, partly because my opinions have been forming over time, which is the intended outcome for the time I am putting into it.

    If you read my last you will see that my thoughts are evolving. Now it seems that efforts to make a car that would use almost no energy are probably wasted, at least there will not be much market encouragement for some time.

    You are sort of right that the big question is about migrating from “dirty” to “green”, but by using such terms you evade the real objective which is to migrate from high CO2 to low CO2 while still getting along with the things we need to do. (It is clear that you mean the same thing as I do from other of your words.)

    I try hard to not say that plug-ins will never do any good. My car concept has always been a plug-in and some versions will be a hybrid plug-in.. What I do say is that plug-ins that require a lot of energy are bad, and I guess I think this will always be so. The main point in my approach to the car is that it will not require much energy. So whatever the power plant, it will make things a lot better.

    I use the term “marginal” not in the sense you seem to take it. When I talk about the marginal response of the grid to a plugged in car I am trying to demonstrate the incremental effect of a plug-in compared to the status before the plug-in car existed. I perhaps should finish by saying this marginal response will be multiplied by whatever number of million others do the same. I am trying to show that what actually changes as a result of the collection of all plug-ins as far as CO2 goes is not determined by the “mix.” So much of the power resource of the “mix” is from sources that have no capacity to increase their output, so these can not help with added loads.

  14. 714

    704 Rod B

    Pickens was open, yes, and he was clever to jump on the green bandwagon, though he was surely mistaken about how fast that wagon was moving.

    All the Moore’s law applications outside the integrated circuit world are questionable. Even exCEO of Intel, Andy Grove, says that batteries will follow Moore’s law. Surely he must know better. Batteries are more like silicon power semi-conductors which have improved over the years, but the rate is far different from the integrated circuit rate of improvement.

    PV solar technology is also very much limited in rate of improvement. Only by going to different materials has there been much advancement. Maybe there will be more, but I would hesitate to plan on it.

  15. 715
    Nikhil says:

    Jim Bouldin (695)

    “Dubner, at one point, launched into his own private version of global warming theory. He said that rather than CO2-based radiative forcing over the last century plus, the real cause of global warming is the reduction in aerosols over the last couple of decades, in response to air pollution regulations.”

    Wait a minute. This is not false. Nor is it news. Dubner is probably being simplistic and crude, but it was Jim Hansen who said in 2000 something like, “Observed warming of the past century is due primarily to processes other than fossil fuel combustion, the warming from CO2 emissions of which is balanced by the cooling from the aerosols emissions of it.” You can cut and dice radiative forcing any which way you please, but a IPCC 2007 chart I have shows that

    (i) on a 100-year GWP basis, integrated RF for CO2 emissions of year 2000 was about 2.4 w/m2 and of all non-CO2 warming species’ (other LLGHGs and SLGHGs) emissions of the same year, about 1.7 w/m2; this total was negated by cooling of about 1.3 w/m2 from aerosols/aerosol precursors and cloud albedo. Net warming of about 1.8 w/m2. For the CO2 emissions, let’s say 1.6 w/m2 is assigned to fossil fuels, and let’s say fossil emissions of cooling aerosols did about 0.5 w/m2 of cooling. Crudely speaking, fossil CO2’s net contribution, after taking the cooling into account, around 1.1 w/m2 or about 60% of the net warming. You could slack off some on sulfur, nitrogen aerosol control, which doesn’t seem to be that horrible an idea; surely you don’t have to contemplate “hosing”. (Of course, some of the non-CO2 emissions also come from fossil fuel combustion; I ignored them for the sake of this argument because you seem to see a demon in CO2, not the non-CO2 warming agents.)

    (ii) on a 20-year GWP basis, the integrated RF numbers for 2000 emissions are about 0.8, 1.2, 1.3, 0.7; 0.6, 0.5 and 0.1 W/m2 respectively, hence the last number at ~16%. Within the short-term, the time more relevant for policy purposes (and recognizing the inertia in energy infrastructure as Hansen so presciently did in 2000), fossil CO2 contribution to warming is small, and can probably be managed by undoing the gains of SO2 controls since 1995.

    [edit – stick to the science]

  16. 716
    Nikhil says:

    Hank Roberts(676):

    “> I don’t know about the Ogalalla aquifer (me).

    Then you don’t know much about economics.
    How about the Kettleman Hills aquifer? Very different problem.”

    ** I don’t know anything about that either, and that’s good enough for me. The more I learn what I don’t know, the better informed I become. Thank you.**

  17. 717
    Thomas says:

    A sociological comment with historical background: I find it very interesting that Mr. Levitt ends his response to this post with

    “I’m not sure why that is blasphemy.”

    This pondering reveals a commonality with those people who found themselves in the 1990s on the receiving end of criticisms for being prejudiced, biased, or racist in their thinking. You may recall that like Mr. Levitt, those people quickly labeled the criticisms of their behavior as “politically motivated” and they then often sarcastically referred to their behaviors as “politically incorrect.”

    Analogously to the case of Mr. Levitt, the root cause of the conflict was that the majority of these people were in denial about a large-scale shift in the social fabric of America in which it was no longer acceptable for people in the privileged classes to make crude remarks, in jest or otherwise, about people whose skin was a different color, who came from lower class backgrounds, or who had different sexual orientations than they did.

    These people both did not understand *why* it was no longer acceptable to verbally denigrate others (even though simple moral arithmetic was readily at hand to “do the calculation”) nor did they believe that a large number of their fellow citizens had begun to understand and follow this “new morality”.

    Thus, they, like Mr. Levitt, began to feel that they were a class of people under attack for their “independent thinking”. They felt that their views, far from now being socially repugnant, were simply being repressed by some kind of vaguely organized cult of “correctness” that was orchestrated somehow by large unseen but ultimately nefarious forces. Back then, these forces were believed to be a combination of feminists, gays, and people of color that were somehow plotting to destroy our “American way of life” for their own benefit.

    Eventually, these “independent thinkers” began to wear the term “Politically Incorrect” as a badge of honor, as if to say that by being unafraid to make off-color remarks about someone’s sexual identity or skin color affirmed their 1st Amendment rights under the constitution and thus could not be assailed for any other reason. Sadly, what they never seemed to understand was that their comments were at best not helpful, and at worst, as when wielded by people like George Will with access to large media outlets were actually harmful to the larger social goal of reducing racism and sexism and thereby advancing American society into a better future.

    Additionally, these “beseiged” people came to view their “oppressors” not as rational thinking people with clear sociological points to be made, points which they would be glad to argue in a rational manner in debate form, but as quasi-religious “dogma enforcers” whose agenda was driven by some form of “belief system”. This had the convenient effect of removing rationality from the argument and taking the discussion down to the level of “Well you believe my statement to be racist but I believe it to be not-racist, so I guess we’ll just agree to disagree.” This of course stops all debate.

    In the climate “controversy” the role of the shadowy conspiratorial suppressors of independent thinking has now been assigned by the newly “oppressed” group (consisting mostly of oil and coal industry lobbyists and their apologists) to Al Gore, the IPCC, and a vague cadre of “hippie scientists” who continue to try to force their “beliefs” on the rest of us.

    Mr. Levitt’s remark above betrays the fact that this group has, like the racists before them, failed to understand that a very real and very important large-scale shift has occurred in the social fabric of America and indeed the world. In this case, the shift is to a realization that humanity cannot continue to pump Gigatons of CO2 into the Earth’s atmosphere and expect the planet to stay in its currently nicely habitable state.

    Mr. Levitt’s remark betrays the fact that like the “politically incorrect” before him, he has knowingly or unknowingly assigned those who rationally present this new reality to him to the role of quasi-religious “believers” whose arguments are therefore dismissed not as reason-based but as dogma that can be ignored as the “beliefs of others.”

    Mr. Levitt thus, in the same tired way we saw in the 1990s, avoids rational argument by sarcastically saying “Sorry for the blasphemy – I must be politically incorrect!” and refusing to participate further in any rational debate. Unfortunately, “agreeing to disagree” in the case of climate change, or in the field of scientific debate in general, is not an option. Science is unique as a system of human thought in that it relies on external realities that can be objectively and rationally investigated, proven, or refuted.

    There is no room for throwing up of the hands in this debate, Mr. Levitt. Either stand by your position with reason and facts or publish a self-refutation. Show some intellectual courage and stop denigrating science professionals as “believers”. We are scientists, not priests, Mr. Levitt.

  18. 718
    dhogaza says:

    “Dubner, at one point, launched into his own private version of global warming theory. He said that rather than CO2-based radiative forcing over the last century plus, the real cause of global warming is the reduction in aerosols over the last couple of decades, in response to air pollution regulations.”

    Wait a minute. This is not false. Nor is it news.

    How is it not false? Aerosols were greatly reduced in the 1970s, about three decades ago, not “over the last couple of decades”. The last three decades of warming are a clear expression of the CO2 forcing signal.

    [Response: Maybe this is a useful analogy. Suppose someone was poisoning your food, increasing the dose every time, but someone else was keeping you supplied with the antidote. But for some reason the supply of antidote was curtailed so that the poison started to have its full effect. I think most people would agree that the cause of your resulting sickness was the poison, not that the antidote supply dried up. – gavin]

  19. 719
    Rod B says:

    Po (710), but that is not a subsidy to the covered wagon or stagecoach industry per se, as a government contracting with Lockheed-Martin to build a bunch of fighter planes is not a “subsidy” for L-M. You also dismiss the “invisible hand” way to cavalierly. Though, as you say, once in a while a government subsidy is required to accomplish some necessary action that the private economy won’t; or it might just be a government expenditure.

  20. 720
    Rod B says:

    BTW, my 704 should have read AM (Applied Materials), not AMD. I always mix their names up…

  21. 721
    Hank Roberts says:

    Nikhil, understanding the various kinds of aqufers — or the other natural sources from which people extract wealth — is a problem with economics generally. Look up codfish, or tuna, for other examples.

  22. 722
  23. 723
    David Horton says:

    #717 Excellent analysis Thomas, first class clear thinking about the “politically incorrect” mindset. The related “Galileo syndrome” is analysed here

  24. 724
    Hank Roberts says:


    > those who argue for carbon mitigation as the sole
    > route to address global warming …


  25. 725
    Brian Dodge says:

    According to wikipedia the ‘invisible hand’ results in”…prices that are beneficial to all the individual members of a community, and hence to the community as a whole.” Could someone explain in economic terms the benefit of Pet Rocks to the community as a whole? Did the free trade in Credit Default Swaps (not just free, but unregulated to the extent that the total value is only thought to be between 40 and 60 trillion dollars, but may be larger or smaller) result in prices that were beneficial? If the economy has 40-60 trillion dollars of unregulated financial instruments floating around, maybe more, maybe less, how accurately can you quantify M?
    The use of discount rates in financial analysis is based on the presumption that money invested now will increase our ability to buy things in the future; in other words, that I could spend $5 on a sandwich now, or invest the money, and buy 2 sandwiches at some future date.The underlying presumption is that 2 sandwiches will be available and be worth the same at that future time. Since the resources which fuel the economy are finite, surely discounting would be more accurate if it assumed sigmoid instead of exponential growth. But that would mean that fairly weighing future values of CO2 mitigation versus current costs, and comparing them to hypothetical geoengineering proposals would require knowing which particular sigmoid curve applied, and where the inflection point lies(have we already passed Peak Oil? What are the implications if I’m buying fuel instead of sandwiches?).
    Applying conventional economic analysis to environmental policy decisions has even more problems. It will be relatively easy in the future for me to find a sandwich to buy, and there are already things like biodiesel which will be available as substitutes for fossil oil, although the price relative to a sandwich is hard to predict. But there isn’t a market where I can go to buy passenger pigeons, or another Wilkins ice shelf, and since there isn’t any market, saying that preserving the arctic sea ice is worth only X%of our GDP is totally arbitrary.
    “In short, then, the long-term modeling of the costs and benefits of climate change policies used by environmental economists, aside from being a far less accurate tool than its technical precision makes it seem, is systematically biased against policies that are designed to take preventative action now rather than ameliorative action later.”
    Discounting the Discount Rate: Ecocentrism and Environmental Economics J. Samuel Barkin Department of Political Science University of Florida

  26. 726
    Patrick 027 says:

    Re 697 Jim Bullis

    –“I was specifically referring to the report in the Portland OR newspaper about how the legislative analysts had been strongly urged to make low ball estimates of the cost to taxpayers of wind subsidies.”

    Surely that’s not the only analysis ever done?

    The total subsity cost just be subsidy per unit * number of units, summed over categories.

    –“Less obvious but maybe worse is the clamor for wind power where it is said to be cheap, but when looking into the detail it seems to frequently turn out that every opportunity is taken to make it seem better than it is. The costs after subsidy are often reported.”

    Okay, but I don’t think that’s the price given in “A Solar Grand Plan”:
    – – – – – – – –
    “A Solar Grand Plan
    By 2050 solar power could end U.S. dependence on foreign oil and slash greenhouse gas emissions”
    Ken Zweibel, James Mason, Vasilis Fthenakis

    “To provide electricity at six cents per kWh by 2020, cadmium telluride modules would have to convert electricity with 14 percent efficiency, and systems would have to be installed at $1.20 per watt of capacity. Current modules have 10 percent efficiency and an installed system cost of about $4 per watt.”

    (that refers to the cost of a product and service, and presumably is before subsidies)

    “Studies by the Electric Power Research Institute in Palo Alto, Calif., indicate that the cost of compressed-air energy storage today is about half that of lead-acid batteries. The research indicates that these facilities would add three or four cents per kWh to photovoltaic generation, bringing the total 2020 cost to eight or nine cents per kWh.”

    “In 2006 a report by the Solar Task Force of the Western Governors’ Association concluded that concentrated solar power could provide electricity at 10 cents per kWh or less by 2015 if 4 GW of plants were constructed.”

    “Stage One: Present to 2020
    We have given considerable thought to how the solar grand plan can be deployed. We foresee two distinct stages. The first, from now until 2020, must make solar competitive at the mass-production level. This stage will require the government to guarantee 30-year [lo-ans], agree to purchase power and provide price-support subsidies. The annual aid package would rise steadily from 2011 to 2020. At that time, the solar technologies would compete on their own merits. The cumulative subsidy would total $420 billion (we will explain later how to pay this bill).”

    (Note the distinction between an ongoing subsidy to keep an alternative competitives, verses a subsidy to help the transition from one economic pathway to another, which is phased out.)

    “Building 1.5 GW of photovoltaics and 1.5 GW of concentrated solar power annually in the first five years would stimulate many manufacturers to scale up. In the next five years, annual construction would rise to 5 GW apiece, helping firms optimize production lines. As a result, solar electricity would fall toward six cents per kWh. This implementation schedule is realistic; more than 5 GW of nuclear power plants were built in the U.S. each year from 1972 to 1987. What is more, solar systems can be manufactured and installed at much faster rates than conventional power plants because of their straightforward design and relative lack of environmental and safety complications.”

    “Congress could establish the financial incentives by adopting a national renewable energy plan.”… “A solar price support program would secure the nation’s energy future, vital to the country’s long-term health. Subsidies would be gradually deployed from 2011 to 2020. With a standard 30-year payoff interval, the subsidies would end from 2041 to 2050. The HVDC transmission companies would not have to be subsidized, because they would finance construction of lines and converter stations just as they now finance AC lines, earning revenues by delivering electricity.”

    (A lot of unanswered questions here: …
    how much is the cost of the transmission system, etc, and the relationship between CAES and solar power plant output is a bit complex since a CAES system will store solar and wind power supplied over HVDC and output (which I think is AC, to the AC grid) that stored energy, with some conversion loss, possibly combined with some fuel energy, which could be natural gas in the short term, solar/wind hydrogen in the long term – or biofuels, geothermal, etc. The concentrated solar (CSP) considered above was the thermal sort (not CPV), which has trouble for seasonal storage but is dispatchable power on the diurnal and hourly time scale, and the variable solar input can be combined with a complementary fuel input.
    … but there are other sources, for this article and the more recent

    “A Plan to Power 100 Percent of the Planet with Renewables
    Wind, water and solar technologies can provide 100 percent of the world’s energy, eliminating all fossil fuels. Here’s how”
    By Mark Z. Jacobson and Mark A. Delucchi

    ; I haven’t read enough in detail to answer the points you bring up, which I can see are potentially valid, yet you haven’t actually shown me that these studies have committed those errors or confusions that you have identified as possible and/or existing in some work.)
    – – – – – – – –

    –“Rarely is the cost of money included in an analysis.”

    No, the cost of money – if by that, you mean interest rates on lo-ans and dividends on stock, etc, is definitely included. I have seen it listed in a table (there was accounting based on some ratio of debt and equity).

    If it were not, the projected costs would be considerably lower (a $4 per peak W system with capacity factor of 0.25 (the “Solar Grand Plan” placed most solar PV capacity in deserts where average panel insolation could actually allow capacity factors a bit over 0.25, assuming good fill factors, etc.) would have a cost of $16 per installed W; the standard (and very conservative) lifetime considered for PV systems is 30 years, so using 30 years * 8.766 kWh/(W year) = 262.98 kWh/average W, then $16/263 kWh ~= 6.08 cents/kWh. Granted, some of the installation cost might be repeated with inverter replacements at 15 years – although the “Solar Grand Plan” desert installations did not use inverters since, as I understand it, DC power was fed into CAES and AC power was output from CAES; nonetheless, suppose half of that cost is repeated every 15 years, then we get 3.04 + 2*3.04 = 1.5 * 6.08 ~= 9.13 (sum is different from rounding) cents/kWh – on the other hand, halve the one-time cost for a 60-year life, now we’re at 1.25 * 6.08 ~= 7.605 cents/kWh. But I don’t actually know offhand how the proportions work out.)

    –“And the wholesale market costs are often confused with retail electric rates.”

    Potentially good point, but I don’t know if this criticism applies to the work I’m looking at or in the process of tracking down. (And wouldn’t apply so much to rooftop applications, except for the portion that is redistributed over the grid.)

    –“As I said before, I have not found what I would consider to be a real analysis, so I base my opinion on the fact that investors are not willing to get involved without government subsidies. This is not a good indicator for scaleability to a large amount of such energy because the subsidized cost does not indicate the cost of an economically viable enterprise in the long run.”

    Combined with reasonable expectations of economic viability in the long run, this is a good argument for subsidies until costs come down enough for a sufficient portion of alternative options to be competitive on their own, or only with the emissions taxes. Presently we don’t have emissions taxes, so all the more reason for some subsidies for the interim.

    Re 698 Jim Bullis

    –“The problem with getting there is that wind power has to first displace all the operating coal generators, which is theoretically possible, but hard to see happening in many decades.”

    No, all it needs is for wind power to be sold to the grid at equal or lower price than fossil fuel power is sold on the grid.

    Re 713 Jim Bullis

    –“I am trying to show that what actually changes as a result of the collection of all plug-ins as far as CO2 goes is not determined by the “mix.” So much of the power resource of the “mix” is from sources that have no capacity to increase their output, so these can not help with added loads.”

    They help if the capacity is increased sufficiently, or capacity of that and storage are increased, so that there is availability when it would be used.

    Re 697,713

    –“PV solar technology is also very much limited in rate of improvement. Only by going to different materials has there been much advancement. Maybe there will be more, but I would hesitate to plan on it.”

    –“The counter argument is that large scale does tend to bring prices down, but it is a very different situation from the integrated circuit, the evolution of which has been described by Moore’s law. The necessarily huge machinery of wind turbines is at the opposite end of technology from transistors which are ultimately limited by the size of electrons. The appropriate scaling law is more closely related to automobile manufacturing cost experience, and that is an important and more valid way to make judgments. The quantities there of course are much greater, so even there some judgment has to be applied to future predictions.”

    I didn’t think Moore’s law was being used as the justification for expecting costs to improve.

    PV and wind costs, and costs of solar water heaters, etc, should improve with expansion of production and reliable demand for product (the last one might be more applicable to water heaters (?), since the solar PV and wind power manufacturing rates have been growing consistently exponentially), and also with cummulative production to make up for one-time costs, such as private sector R&D and the learning curve.


    Re 715 Nikhil

    –“on a 100-year GWP basis”
    –“on a 20-year GWP basis”

    It’s a bit confusing to use GWP in the context of looking at a history of radiative forcings. Much of the GWP of past CO2 emissions over a long time and methane emissions of only the last decade have yet to be realized.

    Some portion of the GWP of older emissions is no longer contributing to radiative forcing at present.


    Re 717 Thomas – interesting.

    Re 719 Rod B – I am unfamiliar with 710 Po’s example but that is a good general point to remember, that some (or most?) government spending is not subsidy but rather demand of a public consumer.

  27. 727
    Patrick 027 says:

    Re 725 Brian Dodge – “and since there isn’t any market, saying that preserving the arctic sea ice is worth only X%of our GDP is totally arbitrary.”

    Theoretically, it is the least of the available combinations of neutralization or amelioration of the change, adaptation to the change, costs incurred by the change.

    “The use of discount rates in financial analysis is based on the presumption that money invested now will increase our ability to buy things in the future; in other words, that I could spend $5 on a sandwich now, or invest the money, and buy 2 sandwiches at some future date.”

    I think it depends on which discount rate is involved – and this isn’t something I have completely clear, but

    1. there is a discount for uncertainty – if there were an 0.00001 % chance that a civilization-ending, extinction causing asteroid would strick the Earth, then all future changes would be valued at 99.99999 % of what it would otherwise be (I’d think).

    2. the future benifits from technological and other progress, unless climate change or ____ is severe enough to eliminate that.

    3. A given harvest must be divided into what is consumed and what is planted to regenerate the next season’s harvest. There is competition between the present and future uses, hence interest rates. But a few seeds will produce entire plants, so you can forgo a sandwhich now and get more later if other conditions allow.

    If other conditions allow/all other things being equal – of course these contingencies are important.

  28. 728
    Nikhil says:

    Patrick 027

    Re 715 Nikhil

    –”on a 100-year GWP basis”
    –”on a 20-year GWP basis”

    It’s a bit confusing to use GWP in the context of looking at a history of radiative forcings. Much of the GWP of past CO2 emissions over a long time and methane emissions of only the last decade have yet to be realized.

    Some portion of the GWP of older emissions is no longer contributing to radiative forcing at present.

    **I agree. My mistake; loose writing. Actually the numbers are as presented in IPCC AR4 graph with “20-year time horizon” and “100-year time horizon”.

    The precise quote is, “Figure 2.22. Integrated RF of year 2000 emissions over two time horizons (20 and 100 years). The figure gives an indication of the future climate impact of current emissions. The values for aerosols and aerosol precursors are essentially equal for the two time horizons. It should be noted that the RFs of short-lived gases and aerosol depend critically on both when and where they are emitted; the values given in the figure apply only to total global annual emissions. For organic carbon and BC, both fossil fuel (FF) and biomass burning emissions are included. The uncertainty estimates are based on the uncertainties in emission sources, lifetime and radiative efficiency estimates.”

    A 20-year time horizon values current generation more. This is not mere science, it is value, i.e., politics. Scientists who edit out “values” pretending that they don’t do politics actually are even more guilty of playing politics.

  29. 729
    Ray Ladbury says:

    Jim Bullis,
    Moore’s Law long ago ceased to be a law of physics and instead became a law of economic reality for microelectronics manufacturers. The current 45-nm CMOS is a very different beast from the bulky MOS transistors of processes Gordon Moore could envision. Device architecture, doping profiles, materials (especially dielectrics) and microcircuit types and architectures are all novel and are changing increasingly with each new generation. I suggest a perusal of the International Technology Roadmap for Semiconductors.

    The point is that economics can drive technological advance as surely as technological advance can drive economic growth. Rosenfeld’s law applies over many more generations than does Moore’s–and it has done so without the sort of concerted international effort we have see wrt the ITRS.

  30. 730

    729 Ray Ladbury,

    I would prefer not to bring up “laws” which seem to be a poor substitute for thinking about the underlying processes and how they might evolve.

    I do not know what Rosenfeld’s law is. I might guess it was something Art Rosenfeld of the California Energy Commission said, but this will be slow to impress me. Rosenfeld had a hand in making the squigly fluoresent light bulb, which is significant. Our way of dealing with CO2 from coal fired power plants is not so impressive since it is a tax on rate-payers that simply shifts coal use out of California to other states; neither is our self deceiving policy toward electric cars as a CO2 reduction measure. Surely, Rosenfeld should be able to set his politician patrons straight that the “mix” of fuels used to produce electricity is inappropriate in determining the impact of electric cars on CO2 production. We also seem to have trouble remembering physics here in California since the idea that you can compare electric motor efficiency with the efficiency of heat engines runs rampant at all levels of society. I was told by a noted California expert that “if you don’t know that electric motors are more efficient than internal combustion engines you bloody well don’t know much.” Lacking timidity in the face of authority this did not bother me, though my persistence in explaining that efficiency of motors and engines can not be compared may have been a factor in getting me “moderated.”

    In the discussion of how quickly wind turbine costs will decrease, the process that determines cost is much more related to competetion than it is to technology. I think it is closer to automobile machinery than specifically electronic or electrical things. However, there is a different factor of size which may be the most important factor, where scaling up in size might bring the most in cost effectiveness.

  31. 731

    726 Patrick 027

    The sequence of prior comments:

    In 698 Jim Bullis said:

    –”The problem with getting there is that wind power has to first displace all the operating coal generators, which is theoretically possible, but hard to see happening in many decades.”

    Patrick 027 said:

    No, all it needs is for wind power to be sold to the grid at equal or lower price than fossil fuel power is sold on the grid.

    I say: We seem not to be converging on my point about wind power which is that not only does wind power have to be sold at a competitive price, it also has to possess that special thing called “reserve capacity” such that it can respond to added loads. You are right to compare the relative costs if both coal and wind systems are standing ready to fill orders. Otherwise, if wind can not step up to each new load (millions of them)then each such new load will have to draw from coal, which is in fact standing ready to fill orders.

  32. 732
    Ray Ladbury says:

    Jim Bullis,

    Rosenfeld’s Law:'s_Law

    The 1% per year reduction is not striking–the fact that it has persisted for 165 years is VERY impressive. Now, can we help it along?

  33. 733
    Patrick 027 says:

    Re Jim Bullis –

    “Patrick 027 said:
    No, all it needs is for wind power to be sold to the grid at equal or lower price than fossil fuel power is sold on the grid.

    I say: We seem not to be converging on my point about wind power which is that not only does wind power have to be sold at a competitive price, it also has to possess that special thing called “reserve capacity” such that it can respond to added loads. You are right to compare the relative costs if both coal and wind systems are standing ready to fill orders. Otherwise, if wind can not step up to each new load (millions of them)then each such new load will have to draw from coal, which is in fact standing ready to fill orders.”

    If wind power is being sold at a price sufficient to block additional fossil fuel generated power or replace some, that would imply that the capacity exists to do so – this is the situation implied in my statement.

    Add wind power capacity. Sell it at sufficient time-varying price so as to use all that is supplied as it is supplied. Some of this sale may be to energy storers which resell power at a different time at higher price, etc.

    And then you will have reduced, depending on amounts, either the average fossil fuel consumption per unit electricity, or the total fossil fuel consumption in the electricity sector. And this could happen even if a significant portion of transportation is plugged in, in which case, there is a reduction of fossil fuel usage outside the electric power sector. It isn’t automatically the case that emissions are reduced in the process, but it can be made that way.

    (PS Note that when vehicles are plugged in, they won’t necessarily need to consume the same constant power for the duration of being plugged in, in which case, the storage capacity of vehicles can be used to match demand to supply, not by taking power from the vehicles but by varying power supply to the vehicles. Although there is the caveat that vehicles will occasionally be needed at unplanned times, so …)

    Aggregate power consumption over a region has some predictability. CAES, hydroelectric, and peaking natural gas (or biofuels/solar H later?) plants should be able to respond to both unpredicted and predicted fluctuations in mismatches between the rest of the supply and demand on hourly timescales – or shorter ? – I’m not quite sure how fast these things can respond; I have been informed that coal power plants can only ramp up and down slowly, so they could manage a portion of diurnal as well as seasonal variation for an interim period until CAES, etc.

    It isn’t necessary for individual power consumers to match their uses to the supplies they are financially responsible for, and in this, the overall system is more efficient when many users are linked by a transmission grid. The individual ‘weather’ events of power consumption average out across multiple ‘runs’ – thus, within a given category of consumers with similar ‘climates’ of power use, individuals may use power with relatively large and episodic fluctations due to individual events, but as a group, their consumption follows a more predictable pattern that is less jumpy; individuals within such a group need only pay for enough capacity to match the total necessary for the group divided by the number of individuals. Furthermore, multiple groups with varying patterns of usage can effectively exchange the capacity they need for themselves at some times with others at other times, so the necessary capacity for any one group can sometimes be reduced when their peak usage corresponds with off-peak usage of another group, and the groups share.

    And then consider indirect usage in products and services. When a customer is recieving a service, power used at that time to supply the service contributes to aggregate consumption the same way as direct usage. For a commodity product, the unit produced at time t is not made with a particular individual customer in mind; a set of units over time is produced for a set (with fuzzy edges) of customers, who effectively share in the usage of power for each unit at each time. For a production line that makes different products at different times for a non-arbitrary and predictable reason, we would be back to sub-groups with different patterns of usage. When different products are made at different times without a predictable reason or in an arbitrary manner, the end-use customers effectively share in power use over time, and this would go for custom-made products as well (it is up to the producer to pick a time for making that product; the producer will, if there is a way to do so that does not incur too much other expense, try to consume more power when supply is cheaper).

    The point being, in a large enough grid, if I just happen to plug in a car or turn on a microwave oven or whatever at a particular minute of a particular day, when the same day of a different year, under very similar conditions, I might not do so or might use power at a different time of day, I do not need to be responsible for additional capacity to specifically supply that amount of power, because I am part of a group whose total power consumption at any one time is likely significantly less than the sum of peak usage of each individual, because those individual peaks are unlikely to occur at the same time.

  34. 734
    Patrick 027 says:

    Or to put it another way…

    “it also has to possess that special thing called “reserve capacity” such that it can respond to added loads. You are right to compare the relative costs if both coal and wind systems are standing ready to fill orders. Otherwise, if wind can not step up to each new load (millions of them)then each such new load will have to draw from coal, which is in fact standing ready to fill orders.””

    Adding wind capacity will allow it to fill more orders as wind power supply allows.

    Other than that, you could just as easily argue that wind power could never supply energy for any purpose whatsoever.

    You could argue that coal power could also never actually power anything, because, even though coal power is ‘dispatchable’, you still have to add coal power capacity in order to supply more power; otherwise at peak demand there won’t be any reserve capacity and nothing additional plugged in will be able to get power from coal.

    So install the wind and solar power and let them supply electricity.

  35. 735
    Patrick 027 says:

    Re 728 Nikhil

    “A 20-year time horizon values current generation more. This is not mere science, it is value, i.e., politics. Scientists who edit out “values” pretending that they don’t do politics actually are even more guilty of playing politics.”

    Nikhil, you are confusing values with data. Comparing the climatic effect of different emissions using GWP on a time horizon of x years is just a matter of facts. *USING* the GWP of a time horizon of x years to weigh methane emissons against CO2 emissions in POLICY – ie making the tax proportional to GWP+ (+ signifies the CO2 acidification, … etc.) or using a cap that is the sum of variable amounts of CO2 and CH4, etc, where different amounts of one can be traded for different amounts of another – this is assigning value.

    Simply calculating and reporting different GWPs for different time horizons is orthogonal to or perhaps even opposite of ‘editing out values’.

    And anyway, you’re original context, as I recall, was in considering the history of forcings and how a reduction in aerosol emissions (with average cooling effect) helped unmask some of the CO2, etc, warming effect. It would be more clear to consider how the instantaneous radiative forcing has changed over time – this will be comparable to GWPs of aerosol emissions over time, but not so much CH4 and especially not CO2, because the climatic effect of GWP of those emissions from any one year represents the integral of radiative forcing over time out into the future; the integrand is the emission’s contribution to radiative forcing at any time, which will decay with time in some manner but has some nonsignificant portion left after only a few years.

    In the context of changes overall in one direction, GWP is relevant to assigning responsibility of climate change over time to individual emissions.

    GWP is less directly relevant to considering a bump in the overall trajectories. Although there is a lag-time of climate response due to heat capacity, climate changes tend to follow (with lag*) the changes in instantaneous forcing.

    *PS about climate response lags:

    – the rate of initial climate change is proportional to a change in forcing and insensitive to climate feedbacks. For radiative forcing, the rate of change is proportional to (forcing + blackbody radiation response to temperature + other feedbacks)/(heat capacity per unit area)

    where “blackbody radiation response to temperature” is usually negative

    (In some contexts this would also be considered a feedback, and when it is labelled as such, the total feedback must be negative in order for the climate to be stable and tend toward an equilibrium shaped by external forcing. But in the field of climatology, the sign and value of ‘feedbacks’ generally refers to the other feedbacks. It’s possible this is at the root of some confusion, wherein some people insist that the history of climate changes show that the climate is stable, and thus feedbacks must in total be negative. This is generally true (with some possible exceptions – ‘Snowball Earth’), but the other feedbacks besides the blackbody radiation response to temperature are positive and make the total feedback smaller and make the climate sensitivity larger than otherwise.)

    It can be shown that, assuming a linear relationship with constant climate sensitivity (may be a useful approximation, within limits), and considering only feedbacks that act effectively instantaneously (or much faster than the thermal lag time) in response to climate changes, the difference between the climate and the equilibrium climate will decay at a rate proportional to itself, and thus, when external forcing is changed sharply and then held, the climate will exponentially decay toward a new equilibrium with a time scale proportional to climate sensitivity and to heat capacity. (Greater climate sensitivity increases the equilibrium response, but does not change the initial rate of change, since the feedbacks can’t act until the climate actually changes; thus greater climate sensitivity requires more time to reach equilibrium.)

    The heat capacity of the climate system depends on the depth to which thermal signals propagate. Biogeochemical and biophysical feedbacks aside, the climate system may approach equilbrium between the atmosphere, land surface, and upper ocean, long before there is equilibrium of those with the deeper ocean. Continually penetration of the climate change signal down into the crust will go on, but will become so slow that, beyond some depth, the remaining heat capacity of the crust and mantle, etc, can be neglected (except for climate changes associated with moon-forming impacts, etc, or if the sun were removed so that geothermal heating were a significant factor in surface climate).

    Changes in water vapor and ice (in total amount due to transient very small imbalance in global average fluxes due to climate change, not changes in the fluxes that remain at new equilibrium or any other balanced changes in fluxes) add to the effective heat capacity of the climate system via an amount of latent heating/cooling per unit global average temperature change. PS the change in ice might be significant; the change in water vapor has a rather small effect relative to the total heat capacity, even excluding the deep ocean.

    For external forcing reversing fluctuations on smaller timescales, the decay time scale of disequibrilium is not smaller (except wherein effective heat capacity is reduced), but the time lag of reversing climate fluctuations will be smaller, and the extrema of climatic response stay farther away from the extrema in equilibrium response.

  36. 736

    734 Patrick 027

    Reserve capacity from coal fired systems already exists in abundance. That means that equipment is in place that is not being fully used. Thus, such coal fired systems can easily supply energy for any purpose at any time. Nothing has to be paid for and built.

    Reserve capacity from wind powered systems does not exist. Before reserve capacity from wind can exist, the wind systems have to be built out so that wind displaces all coal based supplies. If the economics is right, that can happen fairly quickly. Then reserve capacity can get built. But the economics does not seem to be right. We observe that to be the case when we see that subsidies have to be provided to get anything significant built.

  37. 737
    Hank Roberts says:

    > Coal … Nothing has to be paid for and built.
    Logically then, they don’t need them, they just want to build them anyhow?

  38. 738
    Patrick 027 says:

    Re 736 Jim Bullis

    “Reserve capacity from coal fired systems already exists in abundance. That means that equipment is in place that is not being fully used. Thus, such coal fired systems can easily supply energy for any purpose at any time. Nothing has to be paid for and built.”

    Except fuel costs, which are quite small, and some other costs that are propotional to usage of the facilities (presumably some parts wear out faster when they are used closer to capacity more often; then there’s the pollution control mechanisms). Otherwise, I agree – except when demand peaks, as is known to occur on hot summer days – or is that more the transmission capacity that is pushed to the limit? I guess I don’t know. Of course, the two are not independent – the longer transmission distance capacities are more utilized when local power plants are closer to their limits…

    “Reserve capacity from wind powered systems does not exist. Before reserve capacity from wind can exist, the wind systems have to be built out so that wind displaces all coal based supplies. If the economics is right, that can happen fairly quickly. Then reserve capacity can get built.”

    Actually, depending on the economics, it may be much prefered to minimize reserve direct wind supply. Wind power capacity refers to a maximum power output per turbine, not the potential supply of power which varies between zero and capacity depending on winds. So the effect of reserve capacity occurs when there is reserve potential supply. And the most economical use of wind (and solar) power, is achieved by minimizing unused supply, all else being equal. If storage and/or longer-distance transmission is cheap enough and/or supply fluctuations match demand fluctuations (as solar does to some extent), then reserve supply can be minimized, and instead there will be some reserve capacity in storage/transmission, or lack of need of such when demand and supply better match over smaller regions.

    Anyway, getting clean energy supply to market decreases the fraction of fossil fuel use in the grid. Depending on how much of a CO2 tax is implemented, and other policies, and scarcity changes in natural gas, it may be that the reduction in fossil CO2 emission per unit energy supply is proportionately less than that of the reduction in fossil fuel per unit energy supply. It doesn’t matter so much that the supply can’t be turned up and down at will, so long as it is allowed to displace other power when it is available, which will be affected by how the grid is managed, and – if it is like a free market (this may not be the case as of yet from what I’ve heard, though I don’t know so much about that), this just requires competitive pricing.

    “But the economics does not seem to be right. We observe that to be the case when we see that subsidies have to be provided to get anything significant built.”

    Maybe so. What’s the point? We agree there are externalities involved.

  39. 739
    Hank Roberts says:

    Bad news on HFCs:

    This serves as a reminder that Levitt’s claim he’s arguing with his own strawman creation when says he’s arguing against scientists who think CO2 is the only problem.

  40. 740

    737 Hank Roberts,

    Neat rhetoric. However, you are mixing planning issues with short term decisions.

    But picking up on the planning issue which is also relevant, imagine that coal power plant construction stopped today and only wind and solar stuff was allowed. Assume that the load without plug-ins increased by an amount equal to the present day reserve capacity on coal, so that without wind and solar, further load growth would stop at this theoretical time. So in this scenario, further loads from that point would depend on wind and solar. Wind and solar would extend that theoretical time if these resources were added before that time, so there would be an extended theoretical time. At any time before this extended theoretical time point that an electric plug-in car was plugged in, coal fired capacity would be drawn from (Remember that the wind and solar are immediately used for load without plug-ins. And we would run out of coal fired capacity sooner.

    At the ultimate time we ran out of coal fired capacity, if wind and solar increased further after that, there would be a possibility of load expansion. Otherwise, all new uses of electricity would have to be frozen. (That would have to put a stop to plug-in electric cars as well.) Perhaps the people concerned with the economy take a dim view of this possible future situation, so coal fired plants are being built.

    This planning indicates pessimism about the rate wind and solar will actually come about. Warren Buffet and I agree with this view. (So it seems.)

    This will turn out fine for the purpose of reducing oil dependency.

    However, this situation does indeed portend a disaster for global warming. But it also shows how plug-ins exacerbate the problem.

    In his discussion with Charlie Rose, Warren Buffet threw a crumb to global warming folks, saying, “We will eventually have to wean ourselves off of coal.” I think he has no expectation of doing that in the foreseeable future.

    Jim Bullis thinks the only real answer in view is to cut energy use for transportation by 80% to 90% with a new approach to the automobile and produce triple efficiency power generators to cut CO2 from power generation by about 30% or so. We get encouraging numerical progress this way, but it won’t happen while we still have available such an easy conversion to plug-in cars that will still guzzle energy in massive amounts based on coal fired electricity generation. Things are not looking good from here.

  41. 741

    #732 Ray Ladbury,

    1% per year reduction is not the reduction in energy use according to the stated “Rosenfeld’s Law.” It is the reduction in energy use per dollar of GDP, which is quite a different matter. Assuming the observation is corrected to a real dollar base, and that is not a certainty, it still says more about GDP than energy. GDP is a measure more of trade and commerce. To the extent it relates to manufacturing, the energy needed is interesting.

    The reference in the Wikipedia article that you pointed to is not available. Is it available somewhere for reading?

    Hopefully they also said something about energy use per person, which would be more interesting.

  42. 742
    Steve says:

    Another reason big investors are hesitant about wind and solar is the same reason the average consumer is hesitant about any new technology (new computer, TV, cell phone…).

    What happens if I invest big in wind/solar today, and 3 years from now the technology is 75% better? Should I put my money in something else and wait a few years? (Kinda like waiting 3 more months before buying that new computer, because in 3 months you’ll either pay less for the same system, or buy the new “top of the line” for the same price.)

    Coal technology – it’s been around so long, no one expects significant tech improvements. You dig it, you burn it. The only thing that makes investors hesitant is “How much is the government going to screw me with more taxes/fees in the future?”

  43. 743
    Ray Ladbury says:

    Jim Bullis,
    What is needed is the ability to accelerate the savings we see illustrated by Rosenfeld’s law. After all, the ITRS has managed to maintain the basic trend for Moore’s Law long after the underlying driver (CMOS scaling) petered out. I would suggest that Joe Romm might have a copy of the reference, since, I believe he is a co-author on it.

  44. 744
    Hank Roberts says:

    > Coal technology – it’s been around so long,
    > no one expects significant tech improvements.

    Not correct. When you’re sure of what you learned, look it up with Google to find out what’s happened since you learned it. It’s a poor memory that only works backwards.

    Example search, guessing at keywords:

    Example from the result:

    The newest most efficient coal plants (evil as they are for global warming) are running at temperatures higher than any current nuclear reactor can provide. They’re developing the technology to function at the temperatures we may hope for from fusion reactors some day.

    This is one reason that the idea of swapping out the _old_ coal burners with nuclear fission sources makes sense though. Look at the operating temperature of the GE Prism (Barry Brooks has a lot of information on that kind of technology). That would swap reasonably well into an older coal plant. It’s not hot enough for the newer coal plants.

    The new super-supercritical coal plants are working at much higher temperatures.

    Remember — any technology is going to produce one or two generations of tools beyond the point at which they’re already obsolescent. Think “Spruce Goose” (the biggest wood aircraft, after aluminum was already replacing wood). Or the last of the great big steam locomotives, after diesel-electric was already replacing them.
    Heck, there are even nuclear plants in that “Spruce Goose” category:

    Maybe the newest, most efficient coal plants will look the same way — as outliers, leftover technology improved after it was already on its way out, being replaced by sustainable sources.

    But don’t just assume coal isn’t being improved — check what you believe, because the world changes very fast and whatever we learned is likely out of date.

    And when really high temperature, highly thermodynamically efficient generation heat sources are available — likely fusion — at least the metallurgy will have been done.

  45. 745
    Hank Roberts says:

    Oh, for anyone who didn’t read those links: From the first:

    “The average global efficiency of coal-fired plants is currently 28% compared to 45% for the most efficient plants …”

    From the second:

    “As Les explained, “nothing like this will be built again”. The AGRs at Torness are not ordinary civil power reactors. … They’re sensitive thoroughbreds, able to reach a peak conversion efficiency of 43%. By comparison, a PWR (standard pressurized water reactor) peaks at 31-32%….”

    You have to look this stuff up and see how it’s changing.

    You may not _like_ what people say about these technologies. But you have to be aware that they’re saying it, to be convincing to make your own points about what should be done.

  46. 746
  47. 747

    743 Ray Ladbury,

    If the savings over the last 150 years was real we would not have a problem. I so not think it is important to try to deny the industrial revolution. If there is something real we do not need a “law” to talk about it and an attempt to misinterpret GDP to try to make a plan sound numerical is not helpful.

    Rosenfeld and Romm have both worked hard to cut energy use in California, but both have played a part in policy in California in respect to the electric car. It must be well known that I find this to be a misguided effort. Joe Romm is on record with his insistence that an electric motor is more efficient than an internal combustion engine, and I am on record with insistence that the two kinds of efficiency can not be compared, and in fact, the heat engine making the electricity has to be included in any efficiency claim for a plug-in car. This difference indicates our respective beliefs in the Second Law of Thermodynamics. Rosenfeld and Romm have been diligent in applying the First Law of Thermodynamics. However, the Second Law seems to be a law that has been repealed in California.

    You might imagine, and I think you probably do know, that Joe Romm might not be inclined to send me over a copy of his paper on this.

  48. 748
    Patrick 027 says:

    Re Jim Bullis –

    “(Remember that the wind and solar are immediately used for load without plug-ins. ”

    Or with plug-ins. Either way, they are immediately used for load until storage is developed, although displaced hydropower effectively stores energy.

    But by focussing so much on this point, it seems like you’re manufacturing an issue here. The real issue is costs.

  49. 749

    744 Hank Roberts.

    Your information is correct but you seem to be suggesting that there are a lot of the improved coal fired plants around. I think perhaps not so many based on my calculations using actual data on CO2 emissions from coal, the close relationship that this has with heat, and the output of power from power plants. See for details and complete references. Yes, Hank, actual references that can be studied.

    The actual numbers for power plant efficiencies are very hard to come by. I was only working with the USA totals.

  50. 750
    Ike Solem says:

    There is at least one reason to be hesitant about coal economics, just ask the Aussies:

    The association’s position on the scheme is pure posturing, and industry executives know it even if they will not say so publicly… Another said it was pointless hoping for any endorsement for the carbon scheme out of the coal industry. “This is the pig-shooting community we’re talking about.”

    The real risk to the coal industry, though it may not believe it, is that the world will make a radical reduction in coal use.

    Why? LEDs use less energy than incandescent bulbs per light energy emitted, and electric cars use less energy per mile traveled than combustion-powered cars. Coal-to-gasoline plans, which investors have banked on for future earnings, are thus not so likely to be built without large government subsidies.

    Can the required electricity supply then be met with solar and wind linked to storage and good grid distribution? Yes, that’s been covered several times over. Storage can be distributed (say, a water-heater sized battery rack in the home basement) or centralized (industrial scale hydrogen conversion plants, etc.)

    In this model, the grid is used to coordinate the energy supply between different sources. Without a robust regional grid, any big renewable energy projects will falter (direct solar fuels from atmospheric CO2 are a possible exception). Thus, the grid plays the same role as the roads do – but in the our current world, a handful of groups control the roads and only let certain traffic pass.

    That is also how the Hostmen of Newcastle’s medieval coal trade secured their monopoly – they owned all the boats on the river, as well as all the roads to the coal mining regions.

    Getting back to the issue, Superfreakanomics:

    The fundamental problem with their non-scientific approach is that it doesn’t take into account basic issues like conservation of energy, thermodynamic and kinetic limitations, the role of climate and ecology in food production (fisheries, yes, but also agricultural soils and forests), and so on. This lack of scientific background means that you can be fed nonsense by people who are appear to be scientific experts with good track records, but who have veered of course – for example, Freeman Dyson’s comments about carbon-eating trees being able to absorb fossil fuel emissions…

    The basic economic equations’ of modern academia aren’t grounded in physical reality – or, technically, they don’t account for so-called “externalities.”

    What are externalities? In the thermodynamic 19th century equations that economists adapted for their own purposes, there is system and surroundings – all variables are considered, Physics 101. Kinetic and potential energy, and the related notion of conservation of energy are all based on that notion. There are no “externalities” – excluding divine interventions. This probably accounts for the failure of econometric models to describe reality, by the way. If climate models had a similar failure rate – well, you get the idea.

    For examples of what more realistic economic theories look like: