Freeman Dyson’s selective vision

In the New York Review of Books, Freeman Dyson reviews two recent ones about global warming, but his review is mostly shaped by his own rather selective vision.

1. Carbon emissions are not a problem because in a few years genetic engineers will develop “carbon-eating trees” that will sequester carbon in soils. Ah, the famed Dyson vision thing, this is what we came for. The seasonal cycle in atmospheric CO2 shows that the lifetime of a CO2 molecule in the air before it is exchanged with another in the land biosphere is about 12 years. Therefore if the trees could simply be persuaded to drop diamonds instead of leaves, repairing the damage to the atmosphere could be fast, I suppose. The problem here, unrecognized by Dyson, is that the business-as-usual he’s defending would release almost as much carbon to the air by the end of the century as the entire reservoir of carbon stored on land, in living things and in soils combined. The land carbon reservoir would have to double in size in order keep up with us. This is too visionary for me to bet the farm on.

2. Economic estimates of the costs of cutting CO2 emissions are huge. In an absolute sense, this is true, it would be a lot of dollars, but it comes down to a few percent of GDP, which, in an economic system that grows by a few percent per year, just puts off the attainment of a given amount of wealth by a few years. And anyway, business-as-usual will always argue that the alternative would be catastrophic to our economic well being. Remember seat belts? Why is it that Dyson’s remarkably creative powers of vision (carbon-eating trees for example) fail to come up with alternatives to the crude and ugly process of burning coal to generate electricity?

3. The costs of climate change are in the distant future, and therefore should be discounted, in contrast to the hysterical Stern Report. I personally can get my head around the concept of discounting if the time span is short enough that it’s the same person on either end of the transaction, but when the time scales start to reach hundreds and thousands of years, the people who pay in the future are not the same as the ones who benefit now. Remember that the lifetime of the elevated CO2 concentration in the air is different from the lifetime of CO2 to exchange with the biosphere. Release a slug of CO2 and you will increase the CO2 concentration in the atmosphere for hundreds of thousands of years. The fundamental tenet of civil society is to protect people from harm inflicted by others. Are we a civilized species, or are we not? The question is analogous to using economics to decide whether to abolish slavery. I’m sure it was very costly for the Antebellum Southern U.S. to forego slave labor, but it simply wasn’t an economic question.

4. Majority scientists are contemptuous of those in the minority who don’t believe in the dangers of climate change. I often find myself contemptuous of efforts to misrepresent science to a lay audience. The target audience of denialism is the lay audience, not scientists. It’s made up to look like science, but it’s PR. We have documented Lindzen’s tortured and twisted representation of the science to non-scientists here and here. If Lindzen had a credible argument to support his gut feeling (and apparently Dyson’s), I can promise that I for one would take it seriously. I’ve got kids at home whose future I worry about. If Lindzen were right, no one would be happier about that than me. But I do get contemptuous of BS.

596 comments on this post.
  1. Tim Joslin:

    Marcus (#46), I agree with most of what you say, especially your point 4, which implies the environmental costs of GW damage will actually rise in real terms (a negative discount) and is what we see in practice: e.g. just from the news this weekend, Scotland is prepared to pay to reintroduce beaver after 400 years, and Japan is prepared to recreate wetland from productive agricultural land to reintroduce oriental white storks.

    Re. your point 1: the problem is that the “$s saved by not mitigating” are in fact being spent largely on consumption, rather than investment. Your point 2 is valid, of course, and your point 3 is particularly important. If GW ever destroys fixed capital faster than we can create it then we’re in big trouble. And this is entirely feasible if you consider the potential for sea-level rise to lead to the loss of dozens of large cities. OK, it’s not GW, but to illustrate the point, I read that the recent Sichuan earthquake has destroyed 5m buildings – how many months or even years of Chinese construction does this represent?

    But my main point is that talking about “mitigation costs” is (IMHO) incorrect. Costs to reduce emissions is a second order term. It’s like my girlfriend telling me to slow down on the motorway (=freeway) and me replying that I’ll stop accelerating. In this analogy, it is my speed per se, not how rapidly it is increasing, that is incurring the cost to me of my girlfriend being annoyed. Hence I’m suggesting it would be better to model GHG emissions as a debt, rather than talk about the costs to reduce the rate at which the debt is accumulating.

    Consider Bob Murpy’s numbers (#44): if I have $1400 today I could (A) spend $900 on fossil fuel to heat my home and have $500 left plus a liability of $500 worth of environmental damage at today’s prices that will eventually occur as a result of my GHG emissions or (B) spend $1200 on wind-generated electricity plus $200 left over. My argument is that the $500 worth of damage will increase with GDP, since economic damage caused by GW will be proportionate to the total GDP whenever it occurs (e.g. consider that Stern discusses insurance losses in terms of total global GDP). As the $500 I invest will also increase with GDP, I actually have $0 left in case A. If I’m held accountable for my environmental debt, I’d be better off in case B when at least I’d have the investment proceeds of $200.

    Blair Dowden (#45) notes the “problem” of limiting the timescale to a century. Not only is it wrong to assume an arbitrary cut-off point before the GW problem is actually fixed since the climate will still be here, I suggest that the available precedents suggest no time-limit can be assumed for environmental debts if these are accounted for similarly to any other kind of national (or institutional) debt. I’m sure they told me in school that the country is still paying for the Napoleonic Wars (I’m in the UK). I now doubt that this is literally true in a direct sense, but even if it’s not the case that the war bonds issued then are still in circulation, the debt has been rolled over since, or at a minimum the UK has been able to borrow less because it was paying the coupon on those bonds. The point is that the precedents are for perpetual debts. The national accounts of developed nations (& many other classes of institution) have been continuous for centuries.

    Also (#45) I understood Stern does not use a zero discount rate, but actually just a “low” one (1.4%). I’m questioning whether the rate should in fact be zero (actually negative because of Marcus’ #46 point 4, as already mentioned, but I don’t want to overplay my hand!).

    In summary, it seems to me that talking about “mitigation costs” accepts the classical economic position that environmental externalities can be ignored, which we now know is too simplistic. The idea of “mitigation costs” implies there’s a cost relative to the default case, which is that e.g. GHG emissions are free. This is incorrect – the default case involves costs (and always has done – GHGs from 100 years ago are contributing to our problems, albeit that they are swamped by more recent emissions) that are not at present being fully accounted for. What we have now realised is that we need to internalise these costs and attribute them to those economic activities causing environmental damage, e.g. by imposing carbon taxes. It therefore seems to me that rather than discussing “mitigation costs”, we should be talking about the “carbon debt” being accumulated by those economic activities resulting in GHG emissions.

  2. Randy Ross:

    I just received my copy of the New York Review with the Dyson article last night and didn’t get to read it until this afternoon.

    I was happy to see that Real Climate responded to the article so quickly, but I urge Real Climate to send its post to the New York Review as a letter. The journal has always printed well thought out responses to its articles and offers the writer of the articles a chance to respond.

    This would be an excellent opportunity to provide information to those who had just read the Dyson article and might be convinced by it. Also, it would be good to see Mr. Dyson defend his ideas. They are interesting, but not very tightly rooted in any probable reality. I am reminded of a comment by Isaac Asimov that, by World War II all science fiction writers had predicted fully functioning humanoid robots, and none had predicted the computer.

    Thanks for an excellent post.

  3. Bob Murphy:

    David wrote:

    My problem is with discounting over long time frames, longer than a human lifetime. What if the ancient Greeks two thousand years ago had come up fossil energy, allowing them to thrive for a couple of hundred years? Would we thank them for leaving us a degraded world? Or do you think there would be some bank account somewhere where we could get all the invested money back, with interest, in compensation?

    If the ancient Greeks had attained our current level of technology, then right now I think we would all be thousands of times wealthier than we currently are. If the Earth were a bit warmer than it is right now, that would definitely be worth the extra wealth; everyone would turn up the AC in his or her hovercraft on the way to his or her 10-hour-per-week job.

    Yes this is a fanciful scenario, but only because you gave me a fanciful assumption and asked about its implications.

    There are billions of people who right now lack basic utilities like clean drinking water and dependable electricity. If they are encouraged (forced?) to try to leapfrog over fossil fuels and go right to solar or whatever, their development will be hindered. And hence their grandchildren will be much poorer than under the business-as-usual case.

    I used the T-bill example just to make the point, but it doesn’t rely on direct lineage. E.g. you and I benefit right now from the capital accumulation of earlier generations. When people work with tools and equipment, their labor is much more productive than if we all had to start from scratch with just nature and our bare hands.

    Obviously, if you think that business-as-usual will lead to catastrophic damages, then a rational response would be to limit GHG emissions in the present, notwithstanding the high cost. But I’m just saying, the way to handle this in economic terms is to realize that the future damages are so high (measured in $$) that, even with discounting, they are still higher than the present costs of mitigation.

    One other point: I want to second the statement of a previous poster, that yes Stern actually does discount future climate damages. This is because of the small probability that those generations won’t exist to enjoy the fruits of our current, costly mitigation efforts. E.g. there could be nuclear war, an asteroid could blow up the world in 2025, etc.

    But Stern does not allow a “pure” discount rate, where the utility of future generations is discounted simply because of its futurity. So that’s why his overall discount rate is lower than Nordhaus’, who bases his on the market’s observed discount rate.

  4. Bob Murphy:

    David Benson wrote:

    Lamont (48) wrote “Why can’t mitigating climate change and GHGs produce economic stimulus, rather than be a drag on the economy?” It can. I opine that it largely will be, due to ingenuity and innovation.

    I agree that human ingenuity will always find ways to make a given situation better. But the point is, requiring a reduction in CO2 emissions takes away our range of options. Other things equal, it necessarily makes us poorer.

    Now of course, most posters here would say other things aren’t equal. They would say the costs of mitigation are outweighed by the avoided damages of further global warming.

    I’m not arguing that point right now. I’m merely saying that it’s not correct to, say, count up the “green jobs” as a benefit of a carbon tax or cap-and-trade program. This is because you would have to then include all the jobs that were destroyed (in SUV manufacturing, coal-fired power plants, etc.) by those measures.

    If the government passed a law forbidding the production of anything that was yellow, that could only make us poorer. By the same token, if the government says industry has to reduce its carbon emissions by x% next year, in and of itself that makes us poorer.

  5. Rod B:

    re 42, 44, 45, 46, et al. This demonizing of economic discounting is simply astounding. First, for the record, it is accountants who (must) convert everything to dollars and cents, or otherwise ignore it. Economists take a much broader view and include qualitative stuff. They do look at things from an economic point of view — assessing costs and returns, e.g., though not always in monetary units.

    Bob Murphy explained discounting in rudimentary easy to understand terms that evidently went flying over many heads here like a jet plane. From what I read here everyone hates discounting because of their presumed outcomes or the guessed-at assumptions that they think might be made by the discounters, as Gavin implied or as Marcus did all over the place (I think). Or like David’s world disaster stemming from the Greeks living it up for 200 years on fossil fuels, though I have no idea what he meant. Marcus says, “…a dollar saved by not mitigating today does indeed lead to greater wealth in the future. …” It should read a dollar saved by not investing in this or that today will give you a dollar + NN cents to invest in a later this or that, which if then costs less that $1.nn proves to be a good deal. But you can’t spend the dollar on a hamburger.

    Simply asking the simple question, “what does it cost” really does not taint the whole process in the least. I agree the assumptions should be both quantitative and qualitative and realistically account for all factors and effects in the assessment.. But demonizing “discounting” per se is somewhat like outlawing multiplication.

    [Response: I meant that I think discounting breaks when it is applied over time spans long enough that the people who pay the eventual costs in the future are not the same as the people making the decision today. I don’t think people a thousand years from now would benefit from our maximizing our profits, the way that the discounting theory would seem to suggest. Instead I think it’s pretty obvious that they would be harmed by us not cleaning up our messes. I think that reaping benefits now by making a persistent mess is unfair to people in the future, no matter what your discounting may say. It all sounds like so much trickle-down, to me. David]

  6. John Mashey:

    re: #51 Tim
    “My argument is that the $500 worth of damage will increase with GDP, since economic damage caused by GW will be proportionate to the total GDP whenever it occurs (e.g. consider that Stern discusses insurance losses in terms of total global GDP).”

    I’m not sure that’s a completely correct interpretation: I think the damage percentage is likely to be higher, and the cost higher, but for different reasons, notwithstanding Stern Section 19.2.

    Please look at the first few paragraphs of post #24. As far as I can tell, Stern does something similar:

    a) P.183, footnote 35 says “Extrapolated version of IPCC’s A2 scenario, characterized by annual GDP (per capita) growth of about 1.9%… Annual average population growth is about 0.6%.” I.e., this would be 2.5% total GDP. {I talked to Bert Metz of IPCC, and he said they just got their economic projections from the usual palces like World Bank.]

    b)) Some costs may be proportional to GDP.

    c) Some costs may be bottom-up rollups of various costs, i.e., like the NRDC report I mentioned. For instance, Stern says “Defending New Orleans alone from flooding during a Category 5 hurricane is expected to cost around $32B.” I don’t think that cost necessarily is proportional to US GDP, although it might well occur that if the cost is that high, but US GDP is not high enough, it won’t be done. Likewise, the costs of managing sea level rise in the SF Bay Area are likely to be whatever they are, rather than just be a percentage of US or world GDP.

    d) Anyway, in some cases, costs are *expressed* as percentages, but were derived as c) over a). If a) turns out to be lower:

    Category b) will have same percentage, lower total.
    Category d) will have same value, higher total.

    My other concern is that a great deal of adaptation needs *energy*, and especially pushing dirt and building with steel and concrete, and such activities seem like they’re going to cost more, and are not amenable to Moore’s Law cost reductions.

  7. Raven:

    Lamont Says:
    “Correct me if I’m horribly wrong, but don’t you get increased economic activity from manufacturing and selling compact fluorescent, solar panels and wind turbines?”

    This is a common economic misperception because it does not take into account opportunity costs. For example, a boy that breaks the cobbler’s window creates economic opportunities for the glassmaker but that is a false benefit because this money would have been spent by the cobbler on something else.

    The economy would have been better off if the cobbler had invested the money in light blubs that would allow him to work later. This would still create some economic opportunities for the glassmaker but it would also improve his productivity and allow him to provide shoes at a lower cost. Repairing a broken window simply forces him to increase his prices to recover the lost money.

    Artificially increasing the cost of energy will create economic opportunities for some but the total wealth of the society will go down because their is less money to invest in things that actually improve productivity.

  8. The Tuatara:

    To build a little on Tim Joslin’s interesting post above, there are two key characteristics of the “climate problem” that conventional economic analysis seems to find difficult. The first is the climate commitment – the fact that there are at present unquantified but inevitable climate changes built into the system as the planet gets back into energy balance. The benefit of mitigation only begins to have effect 20 – 30 years after the expenditure. In that sense, spending on mitigation is rather like making a term deposit in the bank, but with no knowledge of the final payout except a (currently) rather vague notion (in the political domain) that it will be worthwhile. Leave aside the difficulties of dealing with the longer/est term damages. Until we can get a good handle on the near term, it will remain difficult to make good policy decisions. The worst case remains that the tough decisions will not begin to be made until the damage is too obvious to ignore, and that’s when the climate commitment really comes home to roost.

    The other issue is to do with the essentially one-way nature of the changes we can see coming. Getting back to 350ppm as Hansen suggests might enable us to stabilise the climate system, but it will not be the same climate we’ve enjoyed over the last few thousand years. We may avoid the worst outcomes, but the damage will still be large. We will not be able to “restore” the Greenland ice cap in any meaningful way, though we might be able to keep a few polar bears alive on an ice reserve in the far north. And how do you put a price on the presence of an ice cap, or a cost on its loss? Clearly, there has to be some concept of natural capital, but as we’re already spending it instead of living (sustainably) on the interest, we have a bigger problem. The “triple crunch”, I believe it has been called: the combined impact of resource depletion (in its widest sense), population growth (9 billion by 2050), and climate change.

    Until we get economic assessments that deal with all of those at the same time, we are shooting in the dark.

  9. Alexander Ač:

    Discounting and uncertainty: a non-economist’s view by Steve Sherwood can be found here:

  10. Peter Wood:

    I had a read of Dyson’s article, but haven’t read Nordhaus’s book, so I am not sure how accurate Dyson’s interpretation of Nordhaus’s book is. In a passage from a different book written by Dyson he claims that we should not be too worried by climate change because there are significant uncertainties from getting information from global climate models. What Dyson does not understand is that these uncertainties are actually a reason for more action on climate change. The possibility of low probability catastrophic events, or climate sensitivity being significantly greater than the median predicted value, leads to expected costs that are much greater than would be predicted by conventional cost benefit analysis. As Joe mentioned, there has been some important recent work in this area by Marty Weitzman.

    Both the role of uncertainty and an ethical approach to discount rates (where the value of someones life in the future is not significantly less than the value of someones life during the present) undermine Nordhaus’s policy gradualism. There are also uncertainties associated with Integrated Assessment Models (IAMs) such as DICE. An IAM could deal with ‘known knowns’ related to climate change, but I have my doubts about how well it would deal with ‘known unknowns’ or ‘unknown unknowns’.

  11. Greg:

    JCH (#10), Australia is currently receiving more rain than at any point in the records. See the BOM website. Some areas are in drought. Our country has always had drought, and always will do. Google the ‘Federation drought’. Nothing at all to do with supposed climate change, and all to do with a government not willing to take responsibility for water supplies.

  12. Bob Clipperton (UK):

    I hope Mr Dyson’s assumptions that Genetic Engineers will develop “carbon-eating trees” in a few years are based on better theoretical foundations than those of other scientists who also assumed 60 years ago that Physicists like him would crack the nuclear fusion problem in a few years !
    Still waiting for the 50 year technology to come, I’m afraid

  13. Eve Earth Charter Foundation:

    The primary cause of severe climate change is the destruction of the rainforests that form a cooling band around the Earth’s equator. The massive release of carbon that results from cutting down forest trees is far more damaging than the combined greenhouse gas emissions from coal power plants, jet aircraft, ships, trucks and cars.

    This is not properganda from environmental activists and committed tree huggers – this startling information comes directly from an authorative report of the Oxford-based Global Canopy Programme, compiled by the world’s leading rainforest scientists.

    The content of the report was handed onto the United Nations and adds credulence to the unprecedented consensus of more than 2000 climate scientists from the International Panel on Climate Change who all agreed, unequivocally, that the war against climate change will be won – or lost – on the trees that we grow and destroy.

    Deforestation accounts for around 25 per cent or one quarter of the total global emissions of heat-trapping gases. Transport and industry accounts for just 14 per cent of human-made emissions and aviation only 3 per cent, without taking into account the direct damage of jet fumes being ejected directly into the Earth’s fragile atmosphere.

    Is it time to do something?

    [Response: These numbers seem off. Deforestation is about 2 Gton C per year, fossil fuel use and other industrial activities are about 8 or 9, according to a recent PNAS paper by Canadell et al, or the IPCC. Volcanic emission is maybe 0.1 Gton C. You’ve got 25% + 14% + 3% = 42%, is the rest natural according to your report? David]

  14. Barton Paul Levenson:

    Fred Jorgensen writes:

    Re. 15-Brett states that the idea of infinite economic growth is absurd. Nonsense! Economic growth is a function of the human mind and its capacity for knowledge. It’s as large as the universe! Peak oil in a few years will be as important as peak whale oil 120 years ago. Environmentalists frequently sound like Malthusians full of todays limitations as absolutes. Society will always change, the climate will always change, and the human mind will find a way to adapt and prosper.

    Like it or not, physical laws impose limits to growth. We can’t grow our population or our production indefinitely, and we certainly can’t do so at exponentially increasing rates. It’s easy to demonstrate that compound-interest expansion brings us smack up against physical laws in geologically very short periods of time (e.g. 7,000 years or so before population growth must stop, even if we can move anywhere just by wiggling our nose and turn stars and galaxies into food at a whim). In real life we run into obstacles long before that.

    A significant fraction of humanity is not prospering. You can’t translate your experience as a middle-class North American or European into world experience.

  15. Barton Paul Levenson:

    Franko writes:

    The last thing you want is to make CO2 biologically unavailable.

    There’s no realistic prospect of that happening in less than a billion years.

  16. John B Hodges:

    (JBH) I got my B.A. in economics and spent too many years in grad school in economics; I’ve been out of economics for 30 years, so I am rusty. BUT: AFAIK Economics as presently conceived is radically, systemically flawed for dealing with “the environment” and problems thereof. Economists think of “the environment” as a luxury consumer good, when it ought to be thought of as land. Furthermore they mostly ignore land, considering it simply another form of “capital”, assuming that capital and land are perfect substitutes, when in reality they are more often complements. Often they assume waste is nonexistent, NEVER do they model cumulative toxicity. Often they assume “future technology” will give us perfect substitutes for resources that are depleted. They do not consider that “production functions” may change, may BE changed by environmental degradation. Herman Daly is the only economist I have heard of who has seriously faced the question of sustainability, and he is not widely influential.

  17. Philip Machanick:

    The thing I don’t quite get is calling someone who wants to do weird stuff to get rid of carbon emissions a “visionary”, when the real excitement is in moving out of a fossil-fueled world. In computing, we have this thing called Moore’s Law, an example of a learning curve law, which gives us so many times cheaper technology every year. The same is happening with photovoltaics, as well as other renewables. When, on the other hand, you use coal and oil, the price has only one direction to go as demand increases, now that we are starting to hit limits on cheap extraction: up.

    What’s so visionary about wanting to find ways to keep oil and coal front and center? I bet people there were people with really visionary ideas about modernizing the horse and buggy in 1908. Pity about that Henry Ford dude.

    What we really need is to pump R&D $$ into getting solar and wind down to as close as possible to the cost of coal-fired power generation as soon as possible; limited supply is already making coal more expensive (most types have approximately doubled in cost over the last 12 months). Add on carbon taxes to keep it that way as use of renewables reduces pressure on coal demand. Advances in technology will kill the economic damage bogey. Wind and solar can get cheaper if we make the equipment better; making a better power station won’t make oil or coal cheaper.

    “oil shale and tar sands”?? I’m going to invest in a horse whip factory. That was a pretty good business c. 1900. All it needs is a bit of visionary R&D on how to cut the depth of horse manure in the streets.

  18. Eli Rabett:

    Economists have a preference for stating outcomes in currency, which, after all can buy everything. Since much accounting uses this approach to value lives, perhaps in this case, the inverse is appropriate, to evaluate policies by their effects on lives and deaths. Remember, that back in the 60s, the tobacco companies made the calculation that it would be less expensive in dollars to resist bans on tobacco, and there have been millions of lives that ended prematurely since. They were right.

    Climate change denial and now delay follows the same course, Nordhaus’ business has not been to deny but to value inaction cheaply and encourage delay. That string having run out, he now retreats to slow action. Unlike slow food that will leave a bitter taste.

    The real problem with doing nothing now will be the cost in lives not air conditioning later. That means you, your kids and the rest

  19. George Tobin:

    The issue of economic efficiency in the context of AGW fervor is important. Do we impose economically harmful policies that have no meaningful impact on CO2 levels (Kyoto, Stern) just because it feels good to ‘do something’ and impose pain on the untenured materialistic masses?

    The snarky dismissal of Dyson’s thoughts about CO2-eating trees would be more convincing if it were not delivered from the standpoint of an even more distant location in wishful-thinking land: Solutions based on massive world-wide carbon policy mandates [edit] is far more fanciful than any science-fiction style technological approach to AGW.

    [Response: Obviously spending money for no good purpose is pointless so suggesting that this is what anyone is advocating is a strawman argument. As for the rest of your comment, it appears completely divorced from the reality of what anyone is seriously proposing. If you are of the opinion that nothing could possibly work and therefore there is no point trying (whether that is a carbon tax, cap-and-trade, mandates to improve energy efficiency, a switch of subsidies from fossil fuels to renewables etc.), then say so and then we can ignore you. If that isn’t the case, constructively add to the discussion by talking about what you think might work. The ‘wishful thinking’ is associated with people who think that simple criticism makes the whole problem go away. It doesn’t. – gavin]

  20. Dave Raskin:

    This series of comments pretty much makes Dyson’s point. Almost all of the commenters begin with the assumption that the science is settled and then set out to demonize Dyson for claiming it is not and for pointing out that standard economic analysis (presented by Nordhaus) does not support the political agenda of Stern/Gore et al. The two points made by skeptics are: (1) the models are imprecise and fail to take into account complex interactions in the biosphere, and (2) the proponents of more radical regulatory regimes to counter global warming fail to take into account standard economic analysis of costs and benefits. Those two points remain largely unrebutted in (what sounds to me like) the quasi-religious dialogue prevalent in this forum. Suppose that you are a true skeptic trying to get to the right answer and then re-read the above posts. Believe me, you will not be convinced.

    [Response: The two points you make have been quite thoroughly addressed, but you weren’t paying attention. First, regarding Nordhaus, how is it that the same people who are so ready to point out problematic aspects of climate modelling are completely convinced by the kind of economic models that Nordhaus uses? His analysis doesn’t even take the baby steps toward incorporating the probability distribution of harm that Weitzman’s model uses, and if you think that climate models have some aspects that are difficult to get right, you ought to have a look at RICE and DICE. Besides that, there’s the highly questionable issue of the discount rate assumed by Nordhaus and many other economists. David addressed that specifically in his post. Regarding the biosphere, there is in fact a great deal of work on the land carbon cycle, and Dyson is being far too much of a techno-optimist. While there is some chance that the biosphere might moderately increase it’s carbon uptake (which would somewhat delay doubling of CO2), the science also supports a very real possibility that the biosphere will turn around and become a net source of carbon, adding further to the carbon due to fossil fuel burning. That is a real disaster scenario, and it’s not one that can be discounted. It happend once before in a warming world. During the PETM, the biosphere released up to 6000 gigatonnes of carbon into the atmosphere, in the form of CO2. –raypierre]

  21. Bob Murphy:

    The real problem with doing nothing now will be the cost in lives not air conditioning later. That means you, your kids and the rest.

    But this is also the “real problem” with severe restrictions on the use of fossil fuels. As I said earlier, there are billions of people who don’t have what we consider to be necessities of life. They really are dying every day in ways directly traceable to this lack.

    So if your criterion is, “Minimize the number of premature deaths over the next 200 years” or something like that, it doesn’t automatically follow that a massive carbon tax now is the answer. It could be the answer, but it is an empirical question. Many posters here are acting as if altruism for others necessarily implies support for radical curbs on carbon emissions, when it doesn’t. You would have to (a) care about future generations, and (b) agree with some of the more catastrophic predictions, in order to support radical measures today.

    On the issue of discounting, I agree that on the face of it, it sounds crazy to even ask, “How many future people are worth one person today?” But as I tried to get across (obviously not very persuasively) in earlier posts, the fact is that the price of current purchasing power is higher than (right now) the price of purchasing power in the year 2100. So there needs to be some discount rate (and people can argue about how high it should be) to make sure present mitigation efforts are as effective as they can be.

    One final note: I am not saying that the psychological motivation of most “deniers” is concern for people dying of dysentery in Africa today. Of course not. But even so, it is a fact that there are people we know are dying today from poverty. Their efforts to climb out of poverty will be hampered by mitigation proposals. So it’s not simply a matter of, “Do you value human lives?” It’s an empirical an ethical issue of, “Is allowing x more people to die for sure over the next 20 years, counterbalanced by models that lead us to believe we will thus save x+y people over the next 200 years?”

    Incidentally I am not being sarcastic in writing the above. The answer may very well be “yes, it is worth it.” I’m only trying to show that it is a question of balance, to quote Nordhaus. It’s not simply, “Do I value my SUV more than 80 kids 100 years from now?”

  22. mg:

    It is very easy to put a cost on climate change. Take the maps of infrastructure location. Takes the maps of sea level rise at one metre increments. overlap the maps. Knock out each infrastructure node that gets engulfed. add in a cost to rebuild that node at higher ground. sum the costs of node builds. that’s zeroth order estimate. go to first order estimate by examining follow-on effects into supply chains etc. go to next order by … etc. every study that I am aware of has trivialised the cost of climate change.

    [Response: Don’t forget that the cost of climate change is more than just in goods traded in markets. Human suffering, species extinction, loss of ecosystems — some economists have methods to put dollar values on these,but they are all questionable. Amartya Sen favors considering costs more broadly, and not just aggregating them all into currency. Take a look at some of his essays in “Rationality and Freedom.” –raypierre]

  23. Andrew:

    Re: #68 Yes. How good is that money when there’s nothing to buy? Check out the latest issue of Fine Homebuilding and the price builders are paying for old growth timber for its structural and aesthetic values. America’s virgin timberlands were low-valued and wasted at that time. Today, things are different. How much are our grandkids going to be willing to pay for a cool breeze, trees, (I’m channeling Pink Floyd here) and a bit of decent summer weather?

  24. Jeffrey Davis:

    My understanding of the Project Orion was based on the suprising discovery that nuclear explosions can have a pronounced direction. The stand that one of the early explosions was raised on was almost completely undamaged following an explosion. I’m sure that the bomb makers — and the general public — had expected that the blast would develop like a star expanding in all directions at once. If the destructive, chaotic energy goes thataway then an equal force, which theoretically could be channeled, goes the opposite way. Building a ship rigorous enough to withstand the unimaginable acceleration with all of its other systems intact would probably be beyond engineering, but it’s not prima facie ludicrous.

  25. Craig Allen:

    Greg (#61):

    As is made explicit in numerous reports by the Australian Bureau of Meterology (eg. here) and is very apparent in their maps and other data presentations (eg. here) the national rainfall averages obscure the fact that there have been trends toward a considerable increase in rainfall in the Australia’s tropical north west and devastating decreases in the south west and south east. This, in combination with significant increases in temperature that have increased evaporation, has lead to record minimum inflows to streams and rivers in the south, including to the entire Murray Darling Basin which is in a parless state.

    If you are an Australian then I’m sure that you are aware of all this. Why try to misrepresent the dire nature of the reality with which our nation is struggling to cope? Hopefully, by some miracle all the climatologists are wrong. But it is a very slim hope to cling to. I’m no climatologist, but having intently followed the debate here and elsewhere it has become very clear to me that the climate scientists know what they are doing, are honest and that their science is very coherent, clear and supported by the data. By contrast, the denialist PR is self contradictory and is clearly spun and twisted in a deceitful attempt to confuse the lay public.

    Would it not be prudent to accept that the trends we are seeing are probably the early signs of the predicted global warming, to acknowledge that it is very likely to continue to get worse in the manner that the scientists predict, and to start acting now to both limit and adapt to it?

  26. Jim Galasyn:

    Billions wasted on UN climate programme

    Energy firms routinely abusing carbon offset fund, US studies claim

    John Vidal, environment editor
    The Guardian, Monday May 26 2008

    Billions of pounds are being wasted in paying industries in developing countries to reduce climate change emissions, according to two analyses of the UN’s carbon offsetting programme.

    Leading academics and watchdog groups allege that the UN’s main offset fund is being routinely abused by chemical, wind, gas and hydro companies who are claiming emission reduction credits for projects that should not qualify. The result is that no genuine pollution cuts are being made, undermining assurances by the UK government and others that carbon markets are dramatically reducing greenhouse gases, the researchers say.

    The criticism centres on the UN’s clean development mechanism (CDM), an international system established by the Kyoto process that allows rich countries to meet emissions targets by funding clean energy projects in developing nations.

    Credits from the project are being bought by European companies and governments who are unable to meet their carbon reduction targets.

    The market for CDM credits is growing fast. At present it is worth nearly $20bn a year, but this is expected to grow to over $100bn within four years. More than 1,000 projects have so far been approved, and 2,000 more are making their way through the process.

    A working paper from two senior Stanford University academics examined more than 3,000 projects applying for or already granted up to $10bn of credits from the UN’s CDM funds over the next four years, and concluded that the majority should not be considered for assistance. “They would be built anyway,” says David Victor, law professor at the Californian university. “It looks like between one and two thirds of all the total CDM offsets do not represent actual emission cuts.”

  27. George Merrith:

    Actually it was an economic question. The mostly coal burning north-eastern mercantile interests in the United States were opposed to the Antebellum South’s cotton trade with England. I object to your insinuation that Northern monopoly capitalism was motivated by some ulterior moral purpose of which there is no evidence.

    [edit – keep on topic and don’t personalize criticisms]

  28. Chuck Booth:

    Taking his lead from Nordhaus, Dyson writes, “Carbon-eating trees could convert most of the carbon that they absorb from the atmosphere into some chemically stable form and bury it underground.”

    I’m sure genetic engineering holds many surprises in store for us, but, being the non-visionary type that I am, I just can’t imagine giant, non-biodegradable roots or tubers being a feasible means of carbon sequestration, even if they could be created. Aside from the logistical problems (Where would these GM-trees be planted? In place of what? At what cost, and to whom? What happens when the giant turnip-like roots start to fill up the ground, or impact aquifers, or infiltrate sewer systems?) Given the current opposition to fairly innocuous GM crops (e.g.,, it’s not clear why Nordhaus and Dyson at all confident that society will embrace GM-trees having the capability of altering our atmosphere and possibly our climate?

    Dyson also writes, “Biotechnology is enormously powerful, capable of burying or transforming any molecule of carbon dioxide that comes into its grasp.” Perhaps, but this unbridled optimism strikes me as far more speculative than the GCMs that skeptics keep trying to refute.

  29. L Miller:

    Issues of practicality aside, is it just me or does anyone else find the idea of genetically a carbon eating/sequestering life form a terrifying stupid idea? What happens if this organism is out there in the wild and CO2 levels have dropped to pre-industrial levels?

    [Response: The answer is that you trigger a Snowball Earth. –raypierre]

  30. Uli:

    Re #53:
    Bob Murphy, this seems interessting. Let’s assume that the world was 2500 BT (before today) at the same point as now.
    The emission would be 9GtC/yr at a growing rate of 3.3%/yr in 2500 BT(, without deforestation).
    Which emission of carbon to the atmosphere would you suggest in your case for the time from 2500 BT to today? Maybe you can give a list with values every 100 yr or so for interpolation.

  31. SecularAnimist:

    Bob Murphy wrote: “There are billions of people who right now lack basic utilities like clean drinking water and dependable electricity. If they are encouraged (forced?) to try to leapfrog over fossil fuels and go right to solar or whatever, their development will be hindered.”

    You assert that “their development will be hindered” but you offer no reason to believe that this would be so. And there is evidence that the opposite is true: that rapidly deploying clean, renewable energy technologies and avoiding destructive fossil fuels is not a hindrance but the key to sustainable development in the poor world.

    With regard to dependable electricity for example, the fastest growing technologies for generating electricity worldwide — by far — are photovoltaics and wind turbines. According to Worldwatch Institute, global production of PV panels increased 51 percent and wind-generating capacity increased 27 percent in 2007 alone, continuing multi-year double-digit growth rates for both technologies.

    In many cases, small-scale distributed photovoltaic and wind-generated electricity is proving to be the most cost-effective and fastest path to rural electrification in the developing world, where the financial, technological and industrial resources to build large centralized power plants of any kind, and the grids to distribute their electricity, don’t exist. Wealthy-nation support for the rapid dissemination of such technologies in the developing world leads directly and powerfully to creating a better quality of life for people there, and also reduces the growth in emissions from electricity generation.

    With regard to clean drinking water, anthropogenic global warming is a grave threat to the drinking water supplies of billions of people all over the world. Ending global warming is an absolutely urgent necessity for preserving drinking water supplies.

  32. Bob Murphy:

    In response to post #70, raypierre wrote:

    The two points you make have been quite thoroughly addressed, but you weren’t paying attention….Besides [Nordhaus’ dubious model], there’s the highly questionable issue of the discount rate assumed by Nordhaus and many other economists. David addressed that specifically in his post.

    Hang on a second. The following is David’s addressing of the issue of discount rates:

    I personally can get my head around the concept of discounting if the time span is short enough that it’s the same person on either end of the transaction, but when the time scales start to reach hundreds and thousands of years, the people who pay in the future are not the same as the ones who benefit now.

    There’s no polite way I can say this, but the above is honestly analogous to me (an economist) criticizing the IPCC at a website like and saying, “Personally, I don’t see why we should put any faith in these models. They can’t even tell me if it’s going to rain next week, so when the time scale goes to hundreds or thousands of years…!”

    So whatever your thoughts on discounting, David’s expression of personal confusion over the practice of economists hardly counts as a thorough disposal of the practice.

    And yes, some people pointed to Weitzman’s work, and the RFF paper. Again, this is analogous to me pointing to Lindzen and saying, “Look, even an MIT expert on this stuff agrees with me! These models are bunk!”

    It’s hard to keep the different objections separate on this thread. As I keep pointing out, a lot of people here don’t like the idea of using dollar measurements in the first place, in which case the discussion of discounting is superfluous.

    But if you are prepared to accept that a cost/benefit test of proposed mitigation measures isn’t absurd, then the next step is to ask whether future costs and benefits should be given equal weight to present ones.

    And I’m saying the answer is no, because whether we agree with it or not, the market right now undervalues future dollars. So we can achieve our aims more cheaply by recognizing this basic fact, rather than declaring it immoral.

    I’ll try one more analogy to get the point across. Suppose there is a homeowner trying to decide whether to spend $1000 renovating the insulation in his house, in order to save $100 on utility bills per year. Should he do it or not?

    If David is right, then before we can answer that question, we need to know how old the homeowner is. After all, if he’s going to die in two years, then clearly the expenditure isn’t worth it, right?

    (The standard answer of course is no, the age of the homeowner is irrelevant, assuming he wants to pass on as much wealth as possible to his heirs. They will reap the benefits of the efficient purchase of insulation. They would rather get the insulated home, and $800 less in cash, than the non-insulated home, and $800 more in cash. [The $200 comes from the two years of life left in the homeowner, in which he lowers his utility bills from the new insulation.])

    [Response: There is a real difference between assessing a discount rate for dollar investments for which clear alternatives are available (i.e. why bother to invest in something special if the bank interest rate is higher than the expected return), and assessing the worth of non-economic goods (‘the social discount rate’). Confusing the two concepts is at the heart of most of the noise surrounding this issue. To give an extreme example for clarity, if someone uses a bomb to blow up someone today, that is surely just as heinous as if they bury the bomb and set it to blow up tomorrow (or next week or next year). It is equally unethical to set the timer for a day in the future as for a hundred years, yet any substantial social discounting would downgrade the crime to a misdemeanor given a long enough lead time. There is a difference and pretending that only the economically illiterate think so, is not constructive. It is however an ethical decision, and can’t be proven one way or another using economics alone. – gavin]

  33. Bob Murphy:

    One final comment, and then I think I should quit while I’m ahead (or not too far behind): Nordhaus is actually on “your” side in this. He has been one of the most vocal economists on the importance of climate change.

    If you think he is unduly activist, it might be because, as a professional economist, he sees costs of your personally favored policies that you aren’t considering.

  34. Bob Murphy:

    Whoops–typo: I meant above to say that if you think Nordhaus’ isn’t activist enough, then it might be because he is worrying about drawbacks to mitigation policies that you aren’t taking seriously. I.e. there seems to be a sense here that because he’s skeptical of some approaches, he must not care about the environment as much as Gore (or Stern) does. And I don’t think that’s it at all. Believe me, I have been a critic of Nordhaus on this very issue, so it’s odd that I’m defending him here. :)

  35. Joe Andersen:

    @8 – There was nothing intrinsically wrong with the Orion concept. It might not be the best engine design we have (and would probably never be usable in our atmosphere) but it is a good idea.

    We should take our own advice, and stick to talking about our areas of expertise – leave the nuclear physics to the nuclear physicists ;).

    Generally, I imagine that the trees Dyson talks about are probably somewhere in our future – the question is whether the trees would come quick enough to stop problems if we just go on with business as usual.

    There is no reason not to pursue ideas like this – all ideas should be pursued to some degree. The danger lies in reliance upon one solution alone.

  36. Bob Werchniak:

    I don’t know what Dyson’s area of expertise is in physics, but imagine if one of us started trying to act as if we understood it in reviewing technical publications dealing with it!

  37. Bob Murphy:

    Well shoot, I said I was done pestering you guys, but then Gavin goes and makes a great analogy that I hope will really clarify our different positions on this. So if you’ll forgive me for one more attempt:

    There is a real difference between assessing a discount rate for dollar investments for which clear alternatives are available (i.e. why bother to invest in something special if the bank interest rate is higher than the expected return), and assessing the worth of non-economic goods (’the social discount rate’). Confusing the two concepts is at the heart of most of the noise surrounding this issue. To give an extreme example for clarity, if someone uses a bomb to blow up someone today, that is surely just as heinous as if they bury the bomb and set it to blow up tomorrow (or next week or next year). It is equally unethical to set the timer for a day in the future as for a hundred years, yet any substantial social discounting would downgrade the crime to a misdemeanor given a long enough lead time.

    OK thanks, as I said this really crystallized our differences on this. Note that we’re actually closer to agreement than you seem to think; all along I have said, “If you don’t want to put a dollar value on lives or the environment, that’s fine. But if you do then you need to discount.” I think we’re both agreed, then, that the basic problem with Nordhaus is his attempt to monetize everything, rather than his application of a discount rate to those monetary values.

    But anyway, back to your example: First of all, under the law you will get a lighter sentence (today) for planting a bomb set to go off in one year, than if you planted one that went off two minutes ago. And the difference of course is that you haven’t actually killed anybody with the first bomb. This is relevant to the climate discussion, because those future harms might not actually occur. And I don’t even mean, maybe carbon-munching trees will be developed. As I said, Stern discounts the future because of the possibility that those people won’t exist (asteroid, nuclear war, etc.).

    (Now in fairness, you could say, “OK, if the bomb is set to go off in one week, versus one year.” I don’t know what the legal treatment of these cases would be, but in either case you would not be charged with murder, because no one is yet dead.)

    But now let’s make your bomb scenario a little closer to the climate change one, and hopefully you’ll see why I keep insisting that discounting is important. Suppose that instead of just an outright government crackdown on bomb-planting, the government capitulates to the bomb lobbyists and only imposes a $35 tax on every bomb planted. (Maybe most citizens view bomb planting as essential to their way of life.)

    Now in that case, it really would be crazy to not discount the fine based on the timer setting, because otherwise the same crime would be penalized at different levels. E.g. someone today plants a bomb set to go off in one year, and he gets fined $35. Then next year, someone plants a bomb to go off in 24 hours, and he also gets fined $35.

    Both bombers killed one person in the year 2009. But the first bomber paid a higher fine, because he had to pay $35 in 2008, while the second guy had to pay it in 2009. During his trial, the first guy in 2008 could have said, “Hang on a second! Don’t make me pay it now, make me pay the $35 when it actually kills someone.” And naturally he would prefer that outcome, because he could set aside less than $35 today (in 2008 when he’s convicted), and let it roll over to $35 in 2009 when his bomb actually causes damage.

    So that’s one way of seeing why, if you’re going to bring monetary incentives into it, which plenty of environmentalists want to do, then it matters that “current money” is more expensive than “future money.”

    To insist that monetary fees (carbon taxes, prices for cap-and-trade permits, etc.) reflect the prevailing exchange rate between present and future dollars, is no crazier than saying a carbon tax expressed in Japanese yen has to be higher per ton than a carbon tax expressed in US dollars.

    To push the bomb analogy even further, yes it certainly would be better if the bomb planters could be persuaded to set their timers farther into the future, even if we’re solely concerned about minimizing the damages from their actions. This is because we have more time to adapt to the bombs. People in the vicinity can move away, they can buy armor for their cars, etc.

    Obviously I’ve carried the analogy a bit far, but I’m just trying to show that the closer you make it to the actual situation of carbon emissions causing future damages, and especially where the government’s response is to inflict monetary fines on the parties doing the damaging, then you need to use discounting. Otherwise you end up with an outcome that is inferior from everyone’s viewpoint, to what would be achievable if discounting were used.

    [Response: My point was only that ethics are not discountable. It is equally unethical to plant the bomb with a one day setting as with a century setting. Your extension to my analogy is really a stretch to make an ethical point into an economic point – I don’t see that any of your additional assumptions are necessarily valid. But nonetheless, there are clear uncertainties with future actions that mean that something that is almost certain to happen if I plan it for a day ahead, is less certain if I plan for a century ahead. Fine – some kind of allowance needs to be made for that (as Stern does). But there is no reason to think that it should be the same discounting rate that applies to today’s monetary investment decisions. – gavin]

  38. David B. Benson:

    Bob Murphy (54) — Unfortunately you are simply assuming that releasing fossil carbon is completely harmless. Just because there was no dollar cost or penalty associated with doing so (before cap-n-trade or offset schemes) does not mean that real harm was not being done.

    We try to penalize those who introduce toxic wastes into the environment. By your argument, that makes us poorer. Sorry, but you have just illustrated why I put very little credence into anything economists say anymore.

  39. Ike Solem:

    Freeman Dyson is wrong on all counts. It’s pretty amazing to read this, actually.

    Take the fastest-growing carbon absorbing plants on the planet – sugarcane and bamboo. It is highly implausible that any feat of genetic engineering will increase those ratea of carbon assimilation. Genetic engineering has a very poor track record so far, in any case. Yields are not any higher, and most of the interest so far has been in creating patented and paired herbicide/GMO plant combinations, like RoundUp Ready Soybeans and the like. No amount of genetic engineering is going to make plants grow without water, or while under ten feet of floodwater.

    The carbon that has been added to the atmosphere was added slowly, over a hundred years, from millions and millions of engines and boilers and furnaces, and any realistic plan to “remove it” is going to have to take place over similar timescales – and what, exactly, is the economic incentive for burying carbon? If all carbon-trading credits were limited to actual geological burial of carbon in a fixed, stable form (such as, say, petroleum), then they really would help – but noone is doing that (CO2 gas is not a stable long-term storage form).

    If we could come up with a technology that used solar power to convert water and carbon dioxide to something like crude oil, then we could pump the crude oil back into the original oil wells (maybe). If that sounds ludicrous, it is because it is – but it is less ludicrous than the tree notion.

    Even if we did have these hypothetical “carbon eating trees”, they’d still have to be cut down and buried – because if you cut down a tree and walk away, around 99% of the carbon will end up right back in the atmosphere where it came from. If you plow the carbon into the soil, it will stay for hundreds of years, give or take. To bring atmospheric CO2 down to pre-industrial levels of 280 ppm would require the burial of how many gigatons of charcoal from these trees?

    Keep in mind that right now, fossil fuel carbon emission rates are as high as they have ever been in human history (at 8 gigatons or so) – and are increasing, even accelerating:

    So, an acre of sugarcane can produce as much as 40 tons of cane (30 seems more likely). Brazil currently has 14 million acres of sugarcane. That works out to around half a billion tons – and since a gigaton is a billion tons, we would need 16 Brazils, growing sugarcane around the clock and burying it all in large pits, to offset the current global fossil fuel emissions.

    However, one ton of sugarcane delivers only 250 kg of bagasse, the woody portion, so multiply all the above numbers by four. All we need to offset current global fossil fuel CO2 emissions are 64 Brazils… Hmmmm…. this does not seem possible, does it? How will we dig all the big pits needed, for starters? What will the farm laborers eat (there will be no room for growing food)?

    As far as relying on econometric models and “GDP projections” – that’s not even wrong. If econometric models were ever subjected to the kind of scrutiny that climate models have been subjected to, the entire field would be revealed for what it is – a complete farce. There’s a very good reason that economists never set foot in physical science departments, after all.

    What is needed is massive investment in solar and wind technology and electrical grid storage infrastructure, as well as massive investment in undoing the disastrous “Green Revolution” in industrial agriculture and figuring out how to make out agricultural systems carbon-neutral, at the very least, if not actually carbon negative.

  40. John Mashey:

    re #87 Bob Murphy

    I have the Nordhaus book on order, but obviously haven’t read it yet, since it’s not out, and from reading Nordhaus After Kyoto and Wikipedia I see:

    “To convert from carbon units to the current convention of CO2 units, multiply the mass, or divide the price by 3.67 and “$100 tax per ton of carbon is equal to a tax of $27 per ton of CO2”.

    1 gallon gas ~ 20 lbs of CO2
    1 ton CO2 ~~ 100 gallons of gas or diesel
    $100 per ton carbon = $27.2 / ton CO2 = $.27/gallon, considered a “relatively high” rate, whereas Nordhaus in the above proposes $16/ton for 2010, a $.04 / gallon tax. I’m all for carbon taxes in general, BUT…

    From Dyson’s review, Nordhaus’ analyses sound like they resemble the others:

    1) Project GDP growth forward 100-200 years, usually with some CAGR based on past CAGRs, and typically around 2-3%. This yields a reference case that in no obvious way depends on energy, or specifically Peak Oil&Gas.

    2) Then look at various scenarios, including things like carbon taxes that are presumed to raise prices, discourage usage, and therefore reduce the growth of the economy.

    PLEASE, as an economist, can you explain to me why the following can make even the slightest sense together:

    1) Everybody worries about carbon taxes, i.e., Nordhaus says that $16/ton is the right number for 2010 ($.04/gal), rising to $100/ton ($.27/gal) affecting the economy. This sounds to me like:

    modestly higher fuel prices hurt the economy, if created by taxes, but may be needed to avoid future costs

    2) Oil&Gas production falling to 50% of current over next 50 years has *no* effect on the economy and is irrelevant to reference projections of the future and can mostly be ignored. This sounds to me like:

    substantially higher fuel prices caused by supply-reduction are irrelevant

    How does that work?

  41. David B. Benson:

    Ike Solem (89) — After deeply buying 8.5–9 GtC per year just to stay even, then deeply burying another 385 GtC or so gets us back to about 315 ppm CO2.

    The biomass could be carbonized via pyrolysis with the valuable oils saved for fuel. The biochar (usually called charcoal when the biomass is woody) then has a higher proportion of just carbon.

    Doing some of this might be sensible.

  42. jonp:

    As another economist, I’d like to make a comment (I must say that I have really appreciated Bob Murphy’s contributions).

    There are (at least) three reasons for discounting, all of them reasonable but disputable. (I realise that some of what follows has already been discussed, but I’m trying to clarify.)

    First, there is increasing affluence, which means that on averge an increment to income next year will add less to well-being than an increment today. For the sake of argument, let’s assume that average world affluence (skating over the big problems of averaging) is growing by 3% p.a. Well-being will be growing rather more slowly (since as we get richer each increment to income would be expected to add less to well-being). This might point to a discount rate of say 2% per annum – provided we are confident that affluence will CONTINUE to increase. However, if there is a risk of big reductions in affluence and well-being in future, then we might reasonably pay a lot now to “insure” against that eventuality.

    Second, there is the risk of species annihilation, which means we should “enjoy it while we can”……this argument seems valid, but the risks are very difficult to quantify and the argument justifies only a very low discount rate.

    Third is “impatience” – the simple fact that people prefer a given increment to income now than in a year’s time, irrespective of whether affluence is increasing.

    This third reason seems to me to raise lots of thorny issues. On the one hand, it could be argued that in a democracy, this is the end of the story. People’s savings and investment decisions reflect their ethical choices and governments should simply respect that. On the other hand, it could be argued either that ethics trumps democracy, or that in a democracy, ethical choices are articulated throught democratic processes rather than market ones. Pass.

    But there is a further complication, to which a number of comments have referred. If people’s imatiences is expressed in market transactions, then the use of any dscount rate other than the market one will be wasteful (I think this is Nordhaus’s position). This is because benefits (and therefore well-being) could always be increased by diverting investment away from those mitigation measures which would be justified at a discount rate lower than the market one. However, this seems contentious. It raises the issue of the temporal distribution of benefits. As Gavin points out, how does one ensure that future generations are compensated for climate-induced damage when investments are generally (relatively) short lived? The only answer seems to be that growing faster now results in a more rapid accumulation of knowledge which is then passed on to future generations, resulting in greater productivity and affluence for them. But this seems to me to be a potentially flimsy legacy, particularly over the very long run.

    Basic point: discounting is justifed if we can be reasonbly confident that future generations will be more affluent than the present one (and also to allow for the small risk of species annhilation). But over anything other than the short term this seems to point to a relatively low discount rate (a la Stern, who, as several people have pointed out, does NOT argue against discounting in general). Discounting for impatience looks “iffy” at best. And the critical issue is the risk of catastrophe (short of species annhilation). If there is a big risk of this occuring from climate change (relative to other risks such as asteroids, diseases, etc), then a very low discount rate might be justified. This issue reprsents the boundary between science and economics, and should be a top priority for future research.

  43. Jim Galasyn:

    Study cites high cost of global warming, says action would be cheaper

    By Renee Schoof –
    Published 12:00 am PDT Friday, May 23, 2008

    WASHINGTON – Doing nothing about global warming would cost America dearly for the rest of this century because of stronger hurricanes, higher energy and water costs, and rising seas that would swamp coastal communities, says a new study by economists at Tufts University.

    The study concludes that it would be cheaper to take aggressive action to cut greenhouse gas emissions than it would be to suffer the consequences of a changing world. “The longer we wait, the more painful and expensive the consequences will be,” the report states.

    The Senate in early June will consider legislation to set a declining limit on emissions and establish a market for pollution permits that would reward companies that reduce pollution. The system is designed to reduce total U.S. emissions by 66 percent from 1990 levels by 2050.

    “Most of the debate we expect will be about how much it will cost to implement the bill. This report provides the other side of the ledger – how much it will cost if we don’t act,” said Dan Lashof, director of the climate center at the Natural Resources Defense Council, an environmental group that commissioned the study.

    The Tufts study includes a “bottom-up” analysis of the economic impacts in four categories and says that by 2100, annual costs would be $422 billion in hurricane damage; $360 billion in real estate losses, with the biggest risk on the Atlantic and Gulf coasts, particularly Florida; $141 billion in increased energy costs; and $950 billion in water costs, especially in the West. (The estimates are expressed in today’s dollars.)

    That adds up to an annual loss by 2100 of 1.8 percent of gross domestic product, or GDP, the sum of the nation’s output of goods and services.

  44. Lawrence Brown:

    Comment #70 by Dave Raskin, states in part:”The two points made by skeptics are: (1) the models are imprecise and fail to take into account complex interactions in the biosphere, and…..”

    The global warming over the past 3 and a half to four decades is based on direct observation not climate models.

    He also refers to a “quasi religious” dialogue. Dyson also mentions religion in his review in connection with environmentalism. In response to Reverend Dyson, not wanting to foul our nest isn’t a religious belief among most who are concerned with a clean environment. We use out bathrooms not for worship but to ensure our health and our homes’ very habitability.

  45. John E. Pearson:

    I haven’t read all these posts yet but figured I’d add my two cents since it wasn’t in the top posting. Dyson dismissed solar power along with Nordhaus as being a currently nonexistent technology then goes on to propose carbon sequestration via genetic engineering. To me, that seems a peculiar way of looking at things, but then I’m no Freeman Dyson.

    Another comment regarding this review. I search for everything that Dyson writes because he’s smart as hell. His view on global warming is changing. Before he wrote that the climate scientists are “arm chair scientists” whose simulations didn’t include the mud, the dirt, the dust, the biology, … all this stuff that we don’t fully understand. To my ear, this review struck a very different chord than say what he wrote in “A Many-Colored Glass: Reflections on the Place of Life in the Universe.” I wonder if he was corrected by some field climatologist who take ice cores or who tromps around in the Himalayas or Greenland measuring glaciers ?

  46. Blair Dowden:

    Re #45: Thank you, Gavin, for the Hanemann response to Nordhaus. This is the kind of criticism I am looking for. I wonder if Nordhaus has a response to this?

    Perhaps some of the economists here can help me out the the statement on page 64 comparing a carbon tax with emission caps, that “quantity regulation is better than price regulation if the marginal benefit curve [to reducing climate change] is steeper than the marginal cost curve [of mitigation measures].”

    It seems to me that the issue is how high the carbon tax should be. Quantity controls without a trading scheme are a windfall to producers (ie. oil companies). And an emission trading scheme is always going to be less efficient than a carbon tax.

  47. Dweller:

    BTW Nordhaus’ book is available at his website (.pdf).

  48. jvoe:

    David, Great post, but I’m unsure that the following is correct:

    “Release a slug of CO2 and you will increase the CO2 concentration in the atmosphere for hundreds of thousands of years.”

    About 30% of current annual emissions are, in effect, annually stored in terrestrial ecosystems and the ocean. In the case of the ocean, the turnover time of this CO2 is long enough to be considered out of the contemporary cycle. Cut emissions to zero and wouldn’t there be an immediate drop in CO2, with continuously dropping concentrations until a new “steady-state” was reached?

    I learned at one point that within 200 years atmospheric CO2 would return to pre-industrial levels, if we cut our emissions to zero. I’ve been repeating this since (gulp).

    Is this just wrong…Anyone?


  49. Greg:

    Craig (#75),

    Australia has always had drought, and again there is absolutely nothing exceptional about the current state. You speak of “record minimum inflows to streams and rivers in the south, including to the entire Murray Darling Basin which is in a parless state.”

    As can be seen here, that is wrong. The Murray-Darling gets as much rainfall as ever. No discernable trend. On the same page, you will see that Southern Australia is up on rainfall, South-Eastern is on a downwards trend, but in just about every possible region, rainfall is up compared to early in the 20th century.

    There is nothing radically different about any of the rainfall patterns currently in Australia. There are just more people taking water out of the rivers and lakes. No need for a [edit] climate change explanation.

  50. Erich J. Knight:

    This Biochar technology represents the most comprehensive, low cost, and productive approach to long term stewardship and sustainability.Terra Preta Soils a process for Carbon Negative Bio fuels, massive Carbon sequestration, 1/3 Lower CH4 & N2O soil emissions, and 3X Fertility Too.

    UN Climate Change Conference: Biochar present at the Bali Conference

    SCIAM Article May 15 07;

    After many years of reviewing solutions to anthropogenic global warming (AGW) I believe this technology can manage Carbon for the greatest collective benefit at the lowest economic price, on vast scales. It just needs to be seen by ethical globally minded companies.

    The main hurtle now is to change the current perspective held by the IPCC that the soil carbon cycle is a wash, to one in which soil can be used as a massive and ubiquitous Carbon sink via Charcoal. Below are the first concrete steps in that direction;

    S.1884 – The Salazar Harvesting Energy Act of 2007

    A Summary of Biochar Provisions in S.1884:

    Carbon-Negative Biomass Energy and Soil Quality Initiative

    for the 2007 Farm Bill

    There are 24 billion tons of carbon controlled by man in his agriculture and waste stream, all that farm & cellulose waste which is now dumped to rot or digested or combusted and ultimately returned to the atmosphere as GHG should be returned to the Soil.

    If you have any other questions please feel free to call me or visit the TP web site I’ve been drafted to co-administer.

    It has been immensely gratifying to see all the major players join the mail list , Cornell folks, T. Beer of Kings Ford Charcoal (Clorox), Novozyne the M-Roots guys(fungus), chemical engineers, Dr. Danny Day of EPRIDA , Dr. Antal of U. of H., Virginia Tech folks and many others.