One error retracted, 99 to go. Superfreaknomics authors will, in future editions, correct their claim that Caldeira believes “carbon dioxide is not the right villain”

The outrage over — and debunkings of — the error-riddled book Superfreakonomics continue, even as coauthors Levitt and Dubner slowly concede their mistakes.

Perhaps the most scathing takedown to date comes from Raymond T. Pierrehumbert, the Louis Block Professor in the Geophysical Sciences at the University of Chicago, on RealClimate, in an “An open letter to Steve Levitt.”  Pierrehumbert accuses his U of C colleague of “academic malpractice in your book.”

So far, Dubner has apologized to me for one false accusation in his Sunday, October 18 post attacking my accurate debunking of his book (see here).  Now he has finally conceded on his blog that one of the many key errors I pointed out in his book — that climatologist Ken Caldeira did not believe or ever say that “carbon dioxide is not the right villain in this fight” (see here).  He still has not retracted the countless other mistakes I and others have pointed out.  Indeed, Berkeley economist Brad DeLong urged both authors to “abjectly apologize” for the whole chapter.

And Dubner has not retracted the claim that is still being parroted by the deniers and delayers around the web that I did a “smear” on the book.  It is clear for all to see now that there never was a smear. Everything I wrote in my original debunking was accurate — see Error-riddled ‘Superfreakonomics’: New book pushes global cooling myths, sheer illogic, and patent nonsense “” and the primary climatologist it relies on, Ken Caldeira, says “it is an inaccurate portrayal of me” and “misleading” in “many” places.

I challenge Dubner and Levitt to identify any errors in my critique. Yes, I used strong language in a private e-mail to Caldeira, though nothing near as strong as what Pierrehumbert has written in his public letter to Levitt.  But I challenge either coauthor to identify what charges in that post are false and constitute a smear.

Ironically, by failing to retract the errors I pointed out in my post weeks ago, Levitt has brought upon himself the detailed and devastating takedown by his fellow U of C Professor, which focuses on the same exact errors I debunked.  Pierrehumbert concludes:

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

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


I hope this forever puts to rest the notion that my post’s far less sweeping language was somehow too harsh.  Pierrehumbert accuses Levitt of multiple instances of “academic malpractice,” questioning whether anything Levitt writes can now be trusted.

Anyone who knows climate science or anything about solar energy would have been as outraged as I was in reading the chapter.  Anyone who knows Caldeira’s work, anyone who had read his September comments in the Washington Post — “Geoengineering is not an alternative to carbon emissions reductions,” he said. “If emissions keep going up and up, and you use geoengineering as a way to deal with it, it’s pretty clear the endgame of that process is pretty ugly.” — or anyone who had interviewed him recently on that very subject would have been as outraged as I was by how the Superfreaks misrepresented his work.  And they still to this day don’t get that.  As award-winning journalist Eric Pooley wrote in his Bloomberg story, “Freakonomics Guys Flunk Science of Climate Change“:

Caldeira, who is researching the idea [of aerosol geoengineering], argues that it can succeed only if we first reduce emissions. Otherwise, he says, geoengineering can’t begin to cope with the collateral damage, such as acidic oceans killing off shellfish.

Levitt and Dubner ignore his view and champion his work as a permanent substitute for emissions cuts. When I told Dubner that Caldeira doesn’t believe geoengineering can work without cutting emissions, he was baffled. “I don’t understand how that could be,” he said. In other words, the Freakonomics guys just flunked climate science.

So every single aspect of my initial critique has been thoroughly vindicated by subsequent analysis and reporting, including what I wrote about the infamous “villain” line:

One sentence about Caldeira in particular is the exact opposite of what he believes (page 184):

Yet his research tells him that carbon dioxide is not the right villain in this fight.

Levitt and Dubner didn’t run this quote by Caldeira, and when he saw a version from Myrhvold, he objected to it.  But Levitt and Dubner apparently wanted to keep it very badly “” it even makes the SuperFreakonomics Table of Contents in the Chapter Five summary “Is carbon dioxide the wrong villain?”  It fits their contrarian sensibility, but it makes no actual sense.

As award-winning journalist Eric Pooley wrote in his Bloomberg story, “Freakonomics Guys Flunk Science of Climate Change“:

Caldeira, like the vast majority of climate scientists, believes cutting carbon dioxide and other greenhouse-gas emissions is our only real chance to avoid runaway climate change.

“Carbon dioxide is the right villain,” Caldeira wrote on his Web site in reply. He told Joe Romm, the respected climate blogger who broke the story, that he had objected to the “wrong villain” line but Dubner and Levitt didn’t correct it; instead, they added the “incredibly foolish” quote, a half step in the right direction. Caldeira gave the same account to me.

Levitt and Dubner do say that the book “overstates” Caldeira’s position. That’s a weasel word: The book claims the opposite of what Caldeira believes. Caldeira told me the book contains “many errors” in addition to the “major error” of misstating his scientific opinion on carbon dioxide’s role”¦.

So finally, finally, Dubner writes a post acknowledging this error alone and promising to change it in future editions.  He writes:

Caldeira A1

Here’s Caldeira’s full reply:

A: Reality is just slightly more complex.

I did receive a version in MSWord. I did not read it all but just searched for my name. (I feel no need to fact check things that come in over the transom.)

I highlit the offending sentence and wrote the following comment:

And yet his research tells him that carbon dioxide is not the right villain in this fight.[KC1]

[KC1]My views differ significantly from Lowell‘s and Nathan‘s. I do think we are being incredibly foolish emitting CO2 and that avoiding all of this environmental risk is a good way to invest a few percent of our GDP. My pessimism stems from the apparent difficulties of solving the “prisoner’s dilemma”- and “tragedy of the commons”-type aspects of this problem.

I expected, based on this comment, that the highlit sentence would be removed but did not explicitly request them to remove it. Instead, Levitt and Dubner added a line about “foolish” preceding the line that I was concerned about. So now the text reads:

He believes “we are being incredibly foolish emitting carbon dioxide” as we currently do. Yet his research tells him that carbon dioxide is not the right villain in this fight.

Did I object to the line? Arguably, yes. Was I clear and explicit about not wanting the line in there? No. Was there room for people acting in good faith to differ regarding what my highlighting meant? Yes.

All of the other statements attributed to me are based on fact, although there are differences in detail, nuance, etc.

As I have tried to say several times now: my views, beliefs, policy prescriptions, etc., differ from those of Myhrvold, Wood, Levitt, Dubner, etc., however, I do not question their good intentions.

I can and do frame my own beliefs differently and set them in a different context.

Since Dubner publishes this without disputing it, I assume he agrees with it.

But this response is 100% consistent with what I wrote — and what Pooley wrote based on his interview of Dubner and Caldeira.  The only “just slight” difference, to use Caldeira’s phrase, is whether this was “good faith.”  That is a matter of opinion.  Caldeira is certainly entitled to his view.  Note, by the way, that Caldeira coyly says, “I did receive a version in MSWord.”  Yes, but as Caldeira told me, he received it from Myhrvold, not the authors themselves, which is not standard practice for any book I’ve been involved with or any interview I’ve ever given, not from an author who was supposedly trying to get this important story right.

Pooley clearly doesn’t see this as “good faith.”  And all I wrote was:

Levitt and Dubner didn’t run this quote by Caldeira, and when he saw a version from Myrhvold, he objected to it.  But Levitt and Dubner apparently wanted to keep it very badly “” it even makes the SuperFreakonomics Table of Contents in the Chapter Five summary “Is carbon dioxide the wrong villain?”  It fits their contrarian sensibility, but it makes no actual sense.

The first sentence is what happened.  The first half of the second sentence is my theory, which no one has ever refuted and many have agreed with after reviewing the facts, including Pooley.  Same for the final sentence.  No smear there.

Now Dubner tries mightily in this latest retraction to leave people with the impression that Caldeira doesn’t find any other errors in the book or that he doesn’t think the the book misrepresented his work.  But in fact, as Pooley’s reporting shows, Caldeira did say, just as I reported, the book contained “many errors.”

If you go to Caldeira’s website (click here), he doesn’t send people to the interview above, but rather writes:

For comments on SuperFreakonomics, please see an interview at Yale Environment 360 (21 Oct 2009)

For Caldeira, the Yale interview (which I wrote about here) is his comment for the public on the book (regular readers can skip this part, but I repeat this part for the record):

Yale Environment 360: I want to start with this little dust-up over SuperFreakonomics. In the book, you are quoted as saying, when it comes to global warming, “Carbon dioxide is not the right villain.” Is that accurate?

Ken Caldeira: That is not accurate. I don’t believe I said anything remotely like that because I believe that we should be outlawing the production of devices that emit carbon dioxide, and I don’t think we can solve this carbon climate problem unless we drastically reduce our carbon dioxide emissions very soon.

e360: They also write that you are convinced that human activity is responsible for “some” global warming. What does that mean?

Caldeira: I don’t think we can say with certainty whether we’re responsible for 90 percent of it or we might be responsible for 110 percent of it. But the vast majority of global warming, I believe, is due to human release of greenhouse gases to the atmosphere.

e360: Another thing that plays in to the same kind of sensibility is the idea [which the book quotes Caldeira saying] that the “doubling of CO2 traps less than 2 percent of the outgoing radiation emitted by the Earth.” When that’s phrased like that, it makes it sound like it’s not really much of a problem.

Caldeira: You should think of the whole global warming problem as a 1 percent problem, at least for doubling of CO2. In absolute temperature Kelvin “” scientists like to use the Kelvin scale “” the current Earth temperature is around 288 degrees Kelvin, and a 3-degree warming on top of that is basically a one-percent additional warming. And so this whole issue of climate change, when viewed from an Earth-system perspective, is a story about 1 percents and 2 percents. Two percent might sound like a small number, but that’s the difference between a much hotter world, and the kind of world we’re accustomed to”¦.

e360: Overall, do you feel like your work has been accurately and fairly represented in this book?

Caldeira: The main misrepresentation is the quote that says that CO2 is not “the right villain.” Now, again, I don’t use “villain” talk myself, but if you say what’s the primary gas responsible for the planetary warming, I would say it’s carbon dioxide.

Now, there’s a tougher question when it comes to the other statements that are attributed to me. All of those other statements are based in fact and based on studies that either I have published or other scientists have published. And if we pull back to the case of the biosphere taking up 70 percent of CO2 “” well, yes, we have a published study that said that. It also presented results saying that we might warm up the planet enough to risk melting Antarctica ultimately. And so there is a selective use of quotes.

If you spend several hours talking to somebody and they take a half-dozen things and put it in a book, then it’s going to be in the context and framing of arguments that the authors are trying to make. And so the actual statements attributed to me are based on fact, but the contexts and the framing of those issues are very different from the context and framing that I would put those same facts in”¦

So I think that the casual reader can “¦ come up with a misimpression of what I believe and what I feel about things.

Which is what I wrote.  Indeed, I knew this based on my previous interviews with him, which is why I asked him to make this point, which he did, writing:

So, yes, my representation in the Superfreakonomics book is damaging to me because it is an inaccurate portrayal of me. The problem is the inaccurate portrayal, not my actions or statements.

And then after he emailed me that quote, I took the extra step of explicitly asking him if I could use it, and he said yes because it is what he believes.

So, I made no false statements or smears in my original post or the headline, although I probably should have put that quote in the first post, instead of merely excerpting in the headline.  Dubner’s original post falsely claims that Caldeira didn’t actually say what I wrote in the headline.  But he did.  And, of course, he told the same thing to Pooley and Goodell.

As an ironic aside, a sharp-eyed reader pointed out to me (and sent this screen shot) that in the first version of the retraction Dubner published online this Wednesday, he actually introduced Caldeira’s quote this way:

Caldeira OLD

And Dubner mistakenly linked to the Yale e360 interview! So Dubner knows what was in the Yale interview — much as he knows what Pooley wrote, since Pooley talked to him at length — and thus knows that again it completely vindicates what I wrote.

Dubner still has not corrected his original, false claim that I smeared him, which he wrote on October 18 (emphasis added):

But more broadly, he made it sound as if we had distorted Ken Caldeira’s views in the worst way: “He [Caldeira] has responded to many e-mail queries of mine over the weekend,” Romm wrote. “He simply doesn’t believe what the Superfreaks make it seem like he believes.”

This was the blog post that launched a thousand more. The headlines varied a bit but the general thrust, perhaps inspired by Romm’s exciting headline, was always the same: two guys who aren’t climate scientists wrote a book with a chapter about climate science and one of the main climate scientists in this chapter is saying they badly misrepresented his views.

Yikes. If that were true, I would come after us with pitchforks too.

It is true.

And guess what, even your University of Chicago colleague came after you with the academic version of pitchforks, even noting “the way Superfreakonomics mangled Ken Caldeira’s rather nuanced views on geoengineering.”  So have many others.  Nobelist Krugman wrote, “in this crucial chapter, there’s an average of one statement per page that’s either flatly untrue or deeply misleading.

And Dubner’s false charge against me launched a thousand more.

It is time for Levitt and Dubner to retract the smear charge and issue a bunch of other corrections in their book.  It shouldn’t be hard.  They’ve already retracted one false charge , apologized to me, and agreed to one correction in the book.

21 Responses to One error retracted, 99 to go. Superfreaknomics authors will, in future editions, correct their claim that Caldeira believes “carbon dioxide is not the right villain”

  1. oxnardprof says:

    Better yet, they should retract and rewrite the chapter.

  2. Taylor says:

    Perhaps if people start referring to them as the Fleischmann and Pons of economics, Messrs Levitt and Dubner will rethink and withdraw the book from publication.

    Otherwise, I like the F&P analogy.

  3. Good analogy, but I’m not sure how many people will get it; and I’m even less sure that Levitt &/or Dubner would care.

  4. billy says:

    oh my goodness this is convoluted… (not this post itself but the nature of the discussion). Reminds me I’m glad I’m not an author.
    Re: climate change – someone everyone can unite together to disagree with: John Tantillo did a post on his branding blog defending Americans who, in increasing numbers, are rejecting the notion of global warming –

    He blames poor marketing. But also hints at the fact that he’s not buying it either.

  5. Stuart says:

    Physics doesn’t give a fuck about marketing.

  6. Stuart says:

    Sorry Joe, but you can delete or edit that last comment, but that Faux article made my blood boil.

  7. Stuart says:

    I think the main reason American polls are showing that fewer people believe that the climate is warming is because we have had a couple of cold years here – I fight against this attitude every day. It must really drive you crazy to try to explain the difference between weather and climate to people who supposedly are leading us. It is NOT the power of the deniers argument – it’s just what ignorant people see out the window.

  8. ken levenson says:

    The RealClimate open letter was beautifully done…showing how a devestating take-down doesn’t need to be a street fight. I know it’s not your style Joe (and I’m as big a fan of street fights as any) but there may be something to it.

  9. Gail says:

    This arrived in my mailbox this morning from Paul Gilding – so refreshing to see a focus on what needs to be done rather than the endless refutation of disingenuous denialist propaganda!

  10. Gail says:

    Here is an enjoyable little critique, of a Superfreak sighting in Seattle:

  11. Paul K says:

    Levitt and Dubner now are pushing the ridiculous religion comparison… that scientists are trying to cultivate a cult religion among AGW believers.
    And they continue to censor comments on their NY Times blog. One more post censored today:

    One of the first key attributes of a religion is to stifle dissent. Science thrives on dissent, but it is up to the dissenter to PROVE his conclusions with data.

    The authors of Freakonomics don’t welcome dissent; they censor dissenting views from the blog here.

    The authors of Freakonomics also don’t feel they have to prove their conclusions. In the chapter on global warming, they made the conclusion that “CO2 is not the villain” when it comes to climate change. Their source “data” for this statement supposedly came from Dr. Caldeira. But when Dr. Caldeira disagreed with their conclusion, they now think that by simply dropping the attribution to Dr. Caldeira that they can justifiably still state that “CO2 is not the villain”.

    But they have no climate scientist as the source for this conclusion. And the vast majority of climate scientists disagree. So the authors feel that they are above having to prove any of their conclusion. Their readers must take their dictums on faith alone.

  12. George says:

    I know this is a climate blog, but you should also be aware that they got almost everything else demonstrably wrong too. The drunk-walking chapter has three huge fallacies. First, it is per-mile, not per hour. Obviously in 20 minutes a driver might cover 10x the distance of a walker. second,they ignored the potential for harm to others. Third, drunk-walkers are drunker to begin with — that’s why they didn’t drive!

    also, the carseats. They took 30 years of research. Well, 30 years ago we were only a few years removed from the Maggie Simpson-type carseats, safety seats then being in their first generation. The current generation is far safer than seat belts, duh.

    The whole thing is complete sloppiness that will ultimately cost them their reputation except among the far right.

  13. Col says:

    I’ve only read a couple of your posts on Superfreakonomics, so forgive me if you’ve already addressed this, but is that an exploding watermelon on the cover of the book? Admittedly it’s more orange than red in the middle and then there’s the stem. But I say this because some call greens watermelons thinking (wrongly) that they’re all green on the outside and red (communist) on the inside. Might that explain where they’re coming from and what they’re trying to do? If so, does that mean that the book was intentionally about smearing greens? (Exploding their ideas which they want to paint as myths).

  14. Gail says:

    Interesting, Col, I hadn’t come across that analogy before. Here was my take on the watermelon:

    and you should see what I think about rhubarb!

    It’s a pity that ideology appears to trump science. Fantasy vs. fact. I wonder if your analysis of the cover is valid. It’s quite a tantalizing theory!

  15. Edward says:

    The day we named ourselves “Homo “Sapiens””, Hugh Briss was in town. Maybe if we each had a math coprocessor installed in our brains. This does not apply to RealClimate people or to ClimateProgress.

  16. Anna Haynes says:

    PaulK #11 (“One more post censored today [on NYT Freak blog]”), 4 things:
    1) thanks for documenting this;
    2) it’s not clear from this (#11) comment’s formatting, which part of it is a paste from your Freak comment;
    3) for documentation’s sake, it’s good to provide a URL for the post you commented on;
    4) also for doc’s sake, pictures are worth 1000 words – which is why I made screenshots showing my Freak comment being disappeared, & then posted them at my climate blog, at

    and fyi, I’ve been trying – so far, w/o success – to get Dubner to confirm or deny that he said something rather sly, namely: “The problem today is that people think that the global efforts made towards cutting carbon emissions mean they can go about their lives as normal, it’s almost an excuse for them to pollute.”

    Any suggestions as to how many times & formats one should try, to ask him, before concluding by default that he’s standing by the quote?

    (documented the effort here – )

    And last – does anyone know if Stephen Dubner is related to Jeffrey Dubner of Tapped, originator of the Dubner Oath; and if, well, we can ask Stephen if he’ll take it…

  17. Lou Grinzo says:

    George: “The whole thing is complete sloppiness that will ultimately cost them their reputation except among the far right.”

    And that outcome, if it happens, would constitute a resounding success for the superfreaks. Their goal is not to have a serious effect on public policy or private behavior, or even to have a “good” reputation in the traditional sense of that expression. It’s to make as big a pile of money as possible–that’s just plain economics. So if they become the Rush Limbaugh of economics and science writing–great! They’ll be laughed at, openly ridiculed, and they’ll also have all the book offers, interview requests, and speaking engagements they could want.

    And the worst part of it is that we’re all helping them achieve their goal. That includes CP, my own writing on my blog, and everyone else screaming until their lungs bleed about what these two have said.

    I hate to sound so cynical, but after reading so many comments by and about the superfreaks I really have come to believe that there’s no other explanation.

  18. Gail says:

    Lou Grinzo, you may be on to something. I hadn’t been planning to buy Al Gore’s new book but it was given to me yesterday, and it’s really worthwhile reading.

    It’s time to start ignoring blithering idiotic deniers and controversy feeding profiteers, and start concentrating on near-term solutions that will buy us enough time to sort out long term methods, to avert the worst effects of runaway tipping point crossings.

    Perhaps we should stop wasting intellectual energy arguing with deniers, and just move along without them.

  19. Leif says:

    Gail: I would love to move along without the tin-hats as well. Unfortunately we need their votes and, except for the Shrub Era, by in large a democracy.

  20. Gail says:

    Leif, in the interest of saving trees, I will gladly snailmail you my copy of Gore’s new book as soon as I have finished reading it.

    The science really is settled, as settled as science can be. The real question now is what to do about climate change – not whether it is occurring, or caused by humans.

    Arguing with deniers about that is like arguing with fundamentalist Christians whether the earth was created 10,000 years ago, or billions. WASTE. OF. TIME.

  21. Leif says:

    Gail: Thank you for the offer but save the carbon footprint of shipping and give to a worthy cause locally. Perhaps a local library. I am sure I can get a copy locally although I am fully committed.
    There is a branch of the “fundamentalist Christians that are proponents of “Creation Care.” As an atheist it is still a stretch for me but in reality I care not what they call it as long as they take care of it. This branch was recently lead by Richard (cannot spell his last name but something like “Cizzex”) My wife works with his sister here at the local hospital so I will be able to get his name if need be. He was recently dethroned by the higher ups. That segment still is out there however and is a fairly large portion, if I remember the numbers right. It is however very difficult for them to accept the likes of us. What with our liberal views on abortion, etc. We do need to work with them or at least encourage them to be more vocal.