Ken Caldeira's Carbon Solution

There’s been a brouhaha over whether we “misrepresented” the research and views of the climate scientist Ken Caldeira, whom we write about in the global-warming chapter of SuperFreakonomics. We’ve been in constant touch with him over the past few weeks, since we wanted to amend future printings of our book if indeed there were misrepresentations. If you want to know the end of this story, just skip ahead to the bottom of this post. Otherwise, here’s the background:

Caldeira is working with Nathan Myhrvold and other scientists at the firm Intellectual Ventures on potential global-warming solutions, which include a variety of geoengineering ideas. We cite a variety of Caldeira’s research, primarily on atmospheric carbon dioxide, including these passages:

Caldeira is thoroughly convinced that human activity is responsible for some global warming and is more pessimistic than Myhrvold about how future climate will affect humankind. He believes “we are being incredibly foolish emitting carbon dioxide” as we currently do.


“Twenty thousand years ago,” Caldeira says, “carbon-dioxide levels were lower, sea level was lower — and trees were in a near state of asphyxiation for lack of carbon dioxide. There’s nothing special about today’s carbon-dioxide level, or today’s sea level, or today’s temperature. What damages us are rapid rates of change. Overall, more carbon dioxide is probably a good thing for the biosphere — it’s just that it’s increasing too fast.”


As much as Caldeira personally lives the green life — his Stanford office is cooled by a misting water chamber rather than air-conditioning — his research has found that planting trees in certain locations actually exacerbates warming because comparatively dark leaves absorb more incoming sunlight than, say, grassy plains, sandy deserts, or snow-covered expanses.

But as you can read here (if you really feel like going down a rabbit hole), it was the first sentence of the following paragraph that incurred the scorn of a climate blogger named Joseph Romm:

Yet his research tells him that carbon dioxide is not the right villain in this fight. For starters, as green house gases go, it’s not particularly efficient. “A doubling of carbon dioxide traps less than 2 percent of the outgoing radiation emitted by the earth,” he says. Furthermore, atmospheric carbon dioxide is governed by the law of diminishing returns: each gigaton added to the air has less radiative impact than the previous one.

A noisy conversation ensued, primarily in the climate blogosphere, and we were charged with gravely misrepresenting Caldeira’s views even though we sent him the manuscript for review before publication, and incorporated many of his additions and changes. (For the latest on this conversation, see here, here, or here.)

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?

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.

So, given all this drama, and how extensively Caldeira’s views and research figured in our global-warming chapter, we wrote to him and offered to change anything in the chapter in future printings if indeed we failed to portray his research and views accurately.

Here’s the only change he requested:

You could just change it to “However, carbon dioxide may not be the right villain in this fight” or something like that and not attribute it to me.

Sounds like a good solution. So that’s how future editions of SuperFreakonomics will read. Some critics may of course charge us with making this change only in order to make the first printing of the book more valuable and therefore drive sales. If only we’d been so clever on purpose …

Meme Mine

A Denier's Plea to Global Warming and Climate Change and CO2 Theory Believers:
SAVE THE PLANET you say? The end of the world is kind of the last bullet in anyone's bag of threats don't you think? What's worse than death? You can't raise the stakes after threatening us with death of the planet Earth. You are all in here Buddy. You have bet everything, the house and the farm. There is no going back now as you are: All in! You better show us a crisis soon because cooling trumps predicted warming every time and this public belief in this mistake can't last much longer. History says fear is always a temporary motivator so this CO2 theory is not sustainable for another 23 years.
The validity of Climate Change is heading for a cliff because we know you doomers CAN'T come through with the goods like you global warmers said you would, a promise of climate crisis. And suggesting bad weather is climate change is foolishly transparent and worn out and it's been 23 years of that childishness. Stop this insanity now and we deniers demand the IPCC renounce this theory and work on a new generation energy development.
The smoggy 70's are gone, Rachel Carson Rules and now is the time to put this CO2 mistake aside so we can all come together to protect, preserve and respect our planet and face the future of progress with some dignity, not this fearing the unknown, assuming the worst and fighting a non existent enemy of climate change.
It's not so far fetched to suggest that the likes of Al Gore and David Suzuki could be charged for intentionally holding our countries needlessly on a collision course with death for almost a quarter century.
Let it go people, let it go.


Garrett Pendergast

You boys have opened up almost as big a can of worms as Lomborg did with "The Skeptical Environmentalist". Atta boys!!!!


Are all the new right-wing fans of Levitt and Dubner actually as happy with SuperFreakonomics as they sound? After all, this is a chapter that says flat out that global warming is real and humans caused it.

If the Steves' venture outside of their area of expertise helps the debate turn into "global warming is real and we should do something about it" (the environmentalist position) versus "global warming is real and we should do nothing about it" (the SuperFreakonomics position), that's at least an improvement.


If you really want to do something "freaky," "counterintuitive," etc. how about using your platform to educate people about the scientific peer review process and the way the IPCC actually works? As evidenced by the first comment above, some people simply just don't understand the important ways in which peer-reviewed research differs from comments and opinions published on a blog or in an op-ed with no formal review process and, often, not even any fact-checking. Without understanding the scientific method, of course the public thinks that if one person says 4 and another person says 6, the truth must be somewhere around 5. (Even if the first person is a leading atmospheric chemist and the second, an unqualified shill.)

You two have made your reputation by pointing out cases where careful examination of empirical data leads to results that challenge conventional wisdom. These cases are gratifying to readers because they show us how following strict standards of evidence can lead us to genuinely new discoveries, while "going with our gut" leads us astray. A cool little triumph of intelligence over chaos! But what about those cases where following those strict standards instead leads people to confirm conventional wisdom or add to a consensus? (i.e., most recent work on climate change.) That research isn't as fun or "sexy" but it is every bit as worthy as a manifesto of standards and careful examination of evidence, in a world that prefers easy answers.

I know you like to be provocateurs and I do enjoy your writing for that reason. But having chosen to step into the climate change arena, you have a moral responsibility to stand up and state clearly that you respect and accept the conclusions of the IPCC on what is happening to the climate and to educate your readership on all the care and passion and prudence and plain hard work that those little words "scientific standards" represent.


Gary Henscheid

The oddest thing, in my mind, about the global warming doomsayers, is their incredibly poor ability to prioritize, which leads me to wonder about their claims of being scientists. If they really believed that greenhouse gases, and more specifically, those produced by industry and cars, were a serious threat to the survival of all living things, would those same people be arguing that China, India and other rapidly developing economies deserved a chance to "catch up" to the West for our past emissions? In effect, that's exactly what they are doing by subjecting those countries to air quality control standards much lower than our own.


I'm not quite done reading/listening to the chapter on Global Warming, but my impression was, like with the rest of Super Freakonomics and Freakonomics, this chapter is still focused on how humans are more likely to try to control what they feel (or see directly) that they can control. The point in Super Freakonomics is not that we should not do anything or that it is not yet worth it to do anything, it is simply that we are not focusing on what will actually make the greatest difference against global warming because we want to do what will make us feel like we are doing the most. Or, at least, what we have the most incentive to do.

The Steves bring up the idea of driving a high-efficiency hybrid car to cut carbon emissions but still eating a great deal of red meat and consuming dairy products though the cows raised to produce the dairy products and become the red meat produce a great deal of another greenhouse gas (methane) which acts more strongly than carbon dioxide. They say that it could be just as effective, if not more so, to drive a non-hybrid car (at least to the grocery store) and to not buy as much red meat or dairy.

Why do so many people persist in buying so much red meat and dairy, then, regardless of what kind of car they drive? Just like the voting practices study in the appendix of Freakonomics (at least, the paperback copy I have), people are more likely to do their "civic duty" when they are very visible. It is not only less visible for someone to purchase a different amount of dairy or beef, we are less likely to notice the reduced number of cows being raised and therefore reducing some methane.

Personally, this feels like someone missing the forest for a tree...



I completely understand the Steves' perspective on this, after the initial shock of seeing them toe to toe with the climate change bloggers.

There is no doubt that geo-engineering is a worthwhile avenue to explore however, as Erica points out, the chapter has been written in a way that was designed to provoke and, while this was not the intention, has garnered them a lot of support from right-wing denial fundamentalists.

I think that clarifications like this article are helping to make it clear that they are not denying man made climate change and as a result the "Go Freakonomics, sock it to those hippies" comments are gradually dying down.

Meme Mine's comment did not really fall into this category. In fact it was hard to categorise but a lot of thought had evidently gone into the intriguing rhetorical style.

Joel Upchurch

You might find this article at the Breakthrough Institute interesting: Climate McCarthyism, Part I: Joe Romm's Intimidation Campaign.

L Nettles

- Erica

Erica do you really believe that the IPCC report was an unbiased peer reviewed scientific document?


@ Erica
They do not have a moral obligation to do anything. They are economists.

Eric M. Jones

I think it is a shame that the whole problem has become political. I find myself in the opinion camps of people I would cross the street to avoid. Nevertheless there is hypno hippo know what I mean, on both sides.

I also find it amazing that even people who describe and claim to understand the "Scientific Process" and might in fact have a legitimate claim to actually BEING scientists, are still driven by their inner convictions and rigid beliefs. A real scientists is dispassionate on these issues--inner convictions and firmly-held beliefs are the twin-tailed sirens calling us to disaster.

Why would anyone want to have a "discussion" with anyone who claims s/he cannot be in error, and starts by calling opponents any of several cultish perjorative names?


@Gary - "If they really believed that greenhouse gases, and more specifically, those produced by industry and cars, were a serious threat to the survival of all living things, would those same people be arguing that China, India and other rapidly developing economies deserved a chance to "catch up" to the West for our past emissions?"

Like it or not climate activists do not control the governments of China and India. The only way the US is going to persuade these countries to lower their emissions is to step up and take action ourselves (aka negotiations). They are not going to act if we don't.

NOBODY is arguing that China and India should "catch up" to Western emissions levels. That would be insane. The argument is that they have a right to development, and since Western countries have gotten us to a situation where they must use expensive clean technology rather than the cheap dirty technology we used, developed countries need to help pay some of the cost.

@L Nettles: Well, actually the IPCC conducts review and summary of the existing peer-reviewed literature, not original research. But essentially, yes, I think it's the closest flawed humanity can come to unbiased. I have not seen any evidence suggesting otherwise. Lots of conspiracy theories and speculation about greedy scientists. No evidence.

@Mike - getting an economics degree exempts you from moral responsibility?



You should just make the second edition GLOBAL WARMING OH MY GOD GLOBAL WARMING SCARY typed over and over again. I think that's the only thing you could do that would please your critics.


"Like it or not climate activists do not control the governments of China and India. "

Implying that they do here? Hmmmm.


Yes. On an economics blog, by necessity.

In addition, who's moral obligation are we basing this on?


@Erica: "getting an economics degree exempts you from moral responsibility?"

Economics is when you can show me why Action X is in my best interest. You only need to appeal to morality if you don't care about my economic situation.


Rob@3: Speaking as a "right winger", global warming (or more specifically, climate change) is real. The book does not say that humans alone caused it and it for sure doesn't say that it is worth completely remaking the world's economy in order to stop it. The cost-benefit analysis doesn't work. The world is not going to end because of warming.

Al Gore and the like have sown fear that the planet's coastal areas will be inundated. According to the book, the seas have been rising now for 12,000 years. They've risen 425 feet in that time frame and most of that was in the first 1000 years. Most projections have the seas rising about 18 inches over the next 100 years. So, when the seas rise that .18 of an inch each year, at some point the people in Miami will walk out, see the ocean at their back door, and do something about it. They may build a seawall, they may move or they may dig a moat. And they will bear the cost for that and that is as it should be. But they're not gonna have to swim out of there.

My own personal theory is that Florida is just one giant sandbar anyway. If you look at the way that it is shaped, hurricanes come in from the Atlantic, hit the coast and carve out the coastline as they turn and move north. Over a few hundred thousand years, it is bound to erode the coastline and it has exactly zero to do with man's activities. The harm comes from man having built in that area. Take a look at this Google satellite image, link here:,+fl&sll=35.2522,-80.501088&sspn=0.009743,0.021136&ie=UTF8&hq=&hnear=Miami,+Miami-Dade,+Florida&ll=28.314053,-79.354248&spn=2.688623,5.410767&t=h&z=8

See that underwater ridge offshore of the east coast of Florida? Follow it up the coast; it exactly follows the existing coastline. Do you think that once upon a time the Florida coast was a bit further out at sea? Now zoom out even further, so that you can see both the east and west coasts of Florida and you can see that what is left of Florida is far smaller than what must have existed billions of years ago. For that matter, the entire eastern coast of North America looks like it was bigger. What's going on in Florida is Mother Nature running her course, nothing more. Ocean currents and winds and storms are and have been eroding the coastline and won't stop or even slow down because we suddenly stop emitting carbon.

I love Google's satellite view.



I think that people such as commenter Gary Henscheid need to visit some scientific research centers open days and be introduced to some researchers, so that they can obtain a better understanding of how the research into climate change is being conducted - that not all scientists are left-wing hippies; that the people who the newspapers quote are are only one of thousands of researchers (often the ones guaranteed to give the newspaper the controversial sound-byte they need); that science is rarely just some Albert Einstein fuzzy-haired figure working everything out on a barmat - that it is the convergence of large teams of people's investigations, revealing the unavoidable truth.


I think the one line that really matters in the whole piece is that we, human beings, are effecting change on the planet at a pace that outstrips nature's ability to deal with it. That has always been the issue with the influence of man over nature especially since the dawn of the industrial age where we can alter landscapes and environments virtually overnight


Yes! I have an original print signed by Stephen Dubner. I'm going to be a millionaire!