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 ca
rbon 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:

So what is Caldeira’s own position?

Here’s a block of text he sent me recently that he has labeled “Text Sent to Inquiring Journalists,” which he sends out when someone asks him about the “villain” issue:

Q: Romm says you objected to the “not the right villain” line but Levitt and Dubner left it in anyway. Is that accurate?

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 percent 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 Oct. 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.