Strange Comments From Scott Sumner

He begins a post by quoting this from Paul Krugman:

The chapter opens with the “global cooling” story — the claim that 30 years ago there was a scientific consensus that the planet was cooling, comparable to the current consensus that it’s warming.

And he says:

Why does Krugman keep doing this?  Why does he continually misrepresent what others say?  My theory is that he assumes those he disagrees with are either fools or knaves.  Instead of doing a sympathetic reading, trying to discern what others are really trying to say, he looks for the “gotcha.”  I just read the chapter, and it bears little resemblance to his description.  And I have read a lot of scientific papers on geoengineering, on both sides of the issue, so I know a bit about the field.

The chapter indisputably opens with the global cooling story. There’s just no getting around it. Go here (PDF) and see for yourself. I don’t know what else there is to say about that.

Sumner then disagrees with my view of the political difficulty of using geoengineering:

How is it easier to get international agreement to slow the rise in global warming through policy changes that will cost $100s of billions, if not trillions, as compared to policy changes that will cost less than $1 billion (the big tube)?  Both strategies require international agreement to slow the rise in global temperatures.  But one costs 3 orders of magnitude less.  Can someone explain Krugman’s reasoning to me?  And WWIII?  China is building hundreds of coal plants that will emit lots of carbon and warm the climate, and I don’t see anyone calling for a military attack on China.  So are we to believe that countries will sit back and let others heat up the planet, but attack other countries if they merely slow down the rate at which the earth is warming?  I just don’t get this argument.  As far as I know the geoengineering people are talking about slowing the rise in temps, not cooling the planet below its current level.

I think it takes a distinct lack of imagination and a childlike faith in both the government and the citizenry to believe that pursuing a major geoengineering project would be easy simply because it would “cost” less. Forget international agreement, I strongly suspect that it would be impossible to get a domestic majority in favor of the pump-sulfur-into-the-atmosphere approach. The public doesn’t really trust climate scientists or the government. There was a huge public debate recently concerning “death panels” in the health care legislation, which don’t actually exist. Much of the Republican base believes that the president was born in Kenya. Does this seem like a healthy time to begin discussions about how best to block out the sun?

And imagine if China were unilaterally considering whether to build a sulfur gas pipe. The international community would have major reservations about this, and would probably go to great lengths to prevent its deployment. We went to war over fake weapons in Iraq; you don’t think one nation’s attempt to alter the globe’s weather would generate at least a slight chilling in international relations? Particularly given that this isn’t merely about “slowing the rise in temps.” There could be serious side-effects to such a plan. Even if everyone were on board, it wouldn’t be something to undertake lightly.

Sure, China is already altering climate by building coal plants, but economies have been building coal plants to generate power for over a century, whereas efforts to intentionally alter the climate by pumping tons of sulfur gas into the atmosphere are unprecedented. The two actions are qualitatively different.

It seems obvious to me that a plan like this would be extremely controversial, and would require extensive discussion and dealmaking domestically and internationally, as costs would not be evenly distributed. On top of that it might not work, and it might generate unpredictable and costly side effects. If you’re going to be having a major public debate and extensive international negotiations over a potential climate solution, you may as well cover emission reduction strategies while you’re at it, since it would be utterly irresponsible not to attempt to address climate change both ways.


  1. DM says:

    Krugman writes:

    “the claim that 30 years ago there was a scientific consensus”

    The problem? Dubner and Levitt never make this claim. They do open with a global cooling story, but not once to they say there was any sort of consensus.

  2. DM says:

    Also lost in all this is that the chapter actually discusses some of the issues around deploying a geoengineering solution, but no one seem to want to acknowledge this.

  3. Doug says:

    The big tube? I think nobody really talking about setting up a sulfur dioxide chimney for the environment’s sake ought to call him- or herself a skeptic.

  4. Karl Smith says:

    I don’t know Ryan.

    While its not trivial to get international agreement and domestic consensus on “the big tube” and other projects I think it would be much much easier than getting consensus on slowing carbon emissions for several reasons

    1) Vested interests. Stopping carbon emissions screws certain individuals directly and clearly. They have an incentive to slow the project by any means necessary. Including disinformation.

    As I pointed out before, this is also a hidden danger in creating a permit system. You are now potentially creating vested interests – if as I suspect might be the case some groups are permanently issued free or low cost permits.

    2) You are doing something. When you ask people to stop doing something they want to do you are a spoil sport. When you do something you are a hero. I suspect that even if everyone believed in climate change the legislators who brought about reductions would be seen in history as good concerned statesman, but nothing special.

    However, the President who built the tube is hero. He saved the world. He did what need to be done.

    3) You are not making people feel guilty and indeed you might be assuaging their guilt if the thing works. People do not like to be told they are bad. They love to be told that they can party all night and someone else will clean up the mess.

    4) The scale is such that one power, probably the US, could do it all by itself.

  5. improbable says:

    It seems obvious to me that a plan like this would be extremely controversial, and would require extensive discussion and dealmaking domestically and internationally, as costs would not be evenly distributed.

    This is beyond dispute. An engineering scheme would not be trivial to implement, agree on, pay for.

    But this exact sentence is true of carbon-reduction plans too. They are less controversial in terms of environmental side-effects, but more controversial in terms of economic side-effects (I mean things besides cost: which industries get worst hit, etc.)

    BUT, you can’t sweep away three zeros in cost! That’s the ratio in cost between a coffee and a car, between a suit and a house, it’s not trivial!

    Paying for carbon reductions is by far the biggest hurdle, 80% reductions involve some very serious pain. But 1000 times cheaper… you could afford to ask India and China nicely whether they agree, and ask them to pay nothing. That would make the international co-ordination much easier.

    All of this is assuming there is an engineering solution 1000x cheaper. There may not be. Or it may have such awful side-effects that we choose to leave it alone. But let’s agree that if there was one, and it worked, it would be a wonderful thing. Then let’s put some money towards looking for one.

  6. Mesa says:

    The reason there is heated debate and lack of consensus on action re:CO2 is quite simply that the global electorate is not convinced it’s a problem. Nor should they be, based on questionable historical reconstructions looking backward and hopelessly simplified computer simulations looking forward.

    The global electorate knows that CO2 has increased a lot over the past 100 yrs, and that temperatures have risen a little, and that the planet is still in one piece. The global electorate is intelligent enough to know that there are both winners and losers in any modest warming scenario. And the global electorate is intelligent enough to watch the actual temperature going forward to see if there is a real problem. If there is – it will act, probably in the most cost efficient manner possible. That may or may not be geo-engineering but it’s worth exploring.

  7. Scott Sumner says:

    The global cooling intro was 100% accurate. Krugman says it was inaccurate. What’s so complicated about that? Which sentence in their opening do you think is inaccurate? Krugman defenders will say they created an “impression” of a consensus. I don’t agree, but if “impressions” were the standard, what would be left of Krugman as a blogger? Doesn’t he create the “impression” that they are global warming deniers?
    I agree that geoengineering is a difficult sell politically, and never said otherwise. But I also think getting India and China to reduce CO2 emissions is a tough sell. So I think we need a backup plan. Something to prevent a worst case spike of 5 to 9 degrees in world temps. For the record, I am more optimistic about what could be achieved with a carbon tax than Levitt and Dubner. I wish it had a chance. But alas, that seems to be just one more politically impossible option.

    BTW, I am still waiting for Krugman’s list of 45 false and deeply misleading statements from the chapter.

  8. reason says:

    Re Geoengineering – I suggest everybody read this:

    Bottom line. You still have to reduce carbon emissions. At best you buy some time. And don’t forget ocean acidification.

  9. reason says:

    I hate it when people discuss these costs as thought the net cost is the same as the gross cost! It isn’t, and people should stop trying to pretend it is.

  10. reason says:

    The net cost of geo-engineering processes is probably greater than the direct cost (as there are unknown and almost certainly deleterious side effects) and the net cost of efforts to reduce carbon emissions is almost certainly less than the direct cost (as gains in efficiency are gains in efficiency).

  11. Eli Rabett says:

    The fact is that while there were a number of freakynomics newspaper and magazine articles about “global cooling” in the 1970s, you have to look far and wide to find anything in a peer reviewed journal, and even those are hedged to the hilt. The Freaks are trying to sell a McGuffin.

    You can read about the Great Global Cooling Myth as published in the Bulletin of the American Meteorological Society

    “Despite active efforts to answer these questions, the following pervasive myth arose: there was a consensus among climate scientists of the 1970s that either global cooling or a full-fledged ice age was imminent. A review of the climate science literature from 1965 to 1979 shows this myth to be false. The myth’s basis lies in a selective misreading of the texts both by some members of the media at the time and by some observers today. In fact, emphasis on greenhouse warming dominated the scientific literature even then. The research enterprise that grew in response to the questions articulated by Bryson and others, while considering the forces responsible for cooling, quickly converged on the view that greenhouse warming was likely to dominate on time scales that would be significant to human societies”

    Ryan is right.

  12. Jim Bales says:

    Responding to DM@1 and Scott Sumner @7

    DM posts:
    Krugman writes:

    “the claim that 30 years ago there was a scientific consensus”

    The problem? Dubner and Levitt never make this claim. They do open with a global cooling story, but not once to they say there was any sort of consensus.

    If, in writing the chapter, the authors were aware of the fact that there was no scientific consensus in the 1970’s about the global cooling hypothesis, why didn’t they say so in the text? There is no hint in the text that the accuracy of the global cooling hypothesis was being questioned at the time.

    Mr. Sumner asks:
    Which sentence in their opening do you think is inaccurate?/

    To answer Mr. Sumner’s question, we must recognize that accuracy requires that both i) All facts stated are correct, and ii) All relevant facts are stated. The inaccuracy in the passage is one of omission, and thus the passage as a whole is inaccurate, even if all statements made are true.

  13. kegler says:

    >>> Krugman defenders will say they created an “impression” of a consensus. I don’t agree

    You’d have to put in a lot of effort to read that intro another way.

    Look, L&D are using a common rhetorical technique: opening with a quote or description of events that readers will recognize as applying to some current situation. Then reveal the context, which — surprise! — shows that you were talking about something else, something from the past.

    If they were not trying to create the impression that the predictions of cooling in the 70’s were comparable to the current predictions of warming, then what [i]was[/i] the point of that intro?

    Why bother including those quotes, and presenting them in the way they did? What other purpose could it possibly serve?

  14. Daryl Limkin says:

    “Global warming” (now renamed ‘climate change’) is bullshit.

    The earth has been warming and cooling in cycles for BILLIONS of years, and WILL CONTINUE to do so for billions more. Nothing we do will change that.

    Life will continue to evolve, as it has done for BILLIONS of years. Some species will die out, others will adapt to survive.

  15. Willem van Oranje says:

    There was global consensus in the 70s that we would have jetpacks by the year 2000. I suppose the car- and aviation industry was absolutely foolish to spend so much money on R&D for cars and planes since the 70s?

    There is global consensus that we will be able to cure cancer. Why don’t you start smoking again?

  16. Barry says:

    Scott Sumner Says:
    October 20th, 2009 at 3:57 pm
    “The global cooling intro was 100% accurate. Krugman says it was inaccurate. What’s so complicated about that? Which sentence in their opening do you think is inaccurate? ”

    Scott, perhaps you should have somebody who does not have a Ph.D. from Chicago Econ read that paragraph and explain it to you. I’ve heard that Chicago has some actual high-quality departments, including in literature and the humanities.

    “BTW, I am still waiting for Krugman’s list of 45 false and deeply misleading statements from the chapter.”

    Since you look right at a deeply misleading paragraph, and can’t spot it, you’ll be waiting for the rest of your life, no matter what Krugman gives.

  17. Boonton says:


    The problem? Dubner and Levitt never make this claim. They do open with a global cooling story, but not once to they say there was any sort of consensus.

    The complaint is a bit overstated, but only a bit.

    Dubner and Levitt open with the now famous Newsweek story at the beginning of the chapter, citing quotes of scientists saying climate change is going to be a problem. Then they spring the ‘surprise’. The quotes are not from the present day but from the 70’s and its not global warming but global cooling! Surprise! They then announce that today the consensus is global warming is a problem.

    The problem here is that those of us who follow the debate are very familiar with the Newsweek story. That single issue from the 70’s has been trotted out in the climate debate for years now to make the same stale and lame rhetorical point. “See they thought things were cooling in the 70’s, now they say warming, why trust them when they can’t make up their minds!”

    Those who follow the debate know this makes for a nice sound bite that climate skeptics repeat endlessly, but it is easily refuted if you spend a little time studying the issue. The cooling hypothesis was only an idea by a few scientists that Newsweek briefly ran with because of its cool sci-fi/sci-fact angle. It was never a consensus and never approached anywhere near the support that global warming has. Also one of the prime mechanisms that was supposed to have driven ‘cooling’ was particulate pollution which would block the sun. Since particulate pollution drives smog it was one of the first types of pollution to be attacked by the Clean Air act. Hence, we had a lot less particulate pollution in the late 70’s, 80’s and 90’s than if we had done nothing.

    So a person entirely ignorant of the debate may approach the chapter without making the rhetorical leap of “cooling in the 70’s” = “scientists can’t be trusted”. But a person who does follow the debate, which many of Dubner & Levitt’s critics do, will instantly hear a stale and frustratingly stupid falsehood repeated on the first page of the chapter.

    But then what’s the purpose of the global cooling story? The chapter jumps right into the current consensus on global warming. Is it just to grab the reader’s attention? If so its pretty cheesy since it has absolutely nothing to do with the authors’ argument. Might as well put a picture of a woman in a swimsuit on the cover. By being so critical, Dubner and Levitt are being taken seriously by critics like Krugman and De Long. The alternative explanation is simply bad writing and sensationalistic titles that have little to do with the actual story.