Ever since his “hockey stick” graph of rising temperatures figured prominently in Al Gore’s An Inconvenient Truth, Mann has been at the center of the climate wars. His e-mail messages were among those stolen and widely published last November.
Let’s talk about the hacked e-mails and the ensuing climategate scandal. What happened?
My understanding—and I only know what I’ve read from other accounts—is that hackers broke into the Climatic Research Unit of the University of East Anglia and stole thousands of e-mail messages, which they then proceeded to distribute on the Internet. They even tried to hack into a Web site that I help run, calledRealClimate.
Does anybody yet know where the attack came from?
No. There are many of us who would really like to know because obviously this is a serious criminal breach. And yet there’s been very little discussion, unfortunately, about the crime.
Who might have done the hacking?
It appears to have been extremely well orchestrated, a very professional job. There also appears to have been a well-organized PR campaign that was all ready to go at the time these e-mails were released. And that campaign, involving all sorts of organizations that have lobbied against climate change legislation, has led some people to conclude that this is connected to a larger campaign by special interests to attack the science of climate change, to prevent policy action from being taken to deal with the problem.
Are you talking about the so-called denial machine?
These aren’t my own inferences. I’m talking about what I’ve read on other sites. Interestingly enough, in the January 14, 2010, issue of Nature, there is a review of a book called Climate Cover-Up, by James Hoggan and Richard Littlemore, which details what I’ve just described to you. Back in 2006 there was a perfect storm of sorts. The IPCC had just come out with stronger conclusions. Al Gore’s movie inspired people to get interested in climate change. We had some hot summers; we had some very destructive hurricane seasons. To say hurricane Katrina was an indication of climate change is no more correct than saying the current cold outbreak is evidence against climate change—I mean, that’s weather—but it does influence people. A lot of things came together. There was a concerted effort by special interests who are opposed to policies to combat climate change to retrench and fight even harder in their campaign to discredit the science. There has been a lot more misinformation and, indeed, disinformation about climate change in the public discourse since then.
What about the e-mails themselves? Was it embarrassing having them brought to light?
Nobody likes having their personal e-mail exposed. We can all imagine, I think, what that would be like.
There’s an investigation at Penn State, where you work, into your own role in this. How is that going?
Technically it’s not an investigation. It’s an inquiry to determine if there is a reason for an investigation. [Editor’s note: The inquiry subsequently reported that it had found no credible evidence that Mann had suppressed or falsified data.]
Do you think you and your colleagues did anything wrong?
There’s nothing in any of these e-mails that demonstrates any inappropriate behavior on my part. There are a few things that a certain colleague said that I wouldn’t have said and I can’t necessarily condone, although I can say that they were under a huge amount of pressure. They were attacked by FOIA [Freedom of Information Act] demands. A colleague of mine, Phil Jones, had as many as 40 FOIA demands—frivolous demands—made against him over a single weekend. Frankly, he showed some poor judgment, and there are things I said that I would phrase differently, obviously, if I were saying them in public. But there’s nothing in any of these e-mails, despite the claims of those attacking us, that indicate any sort of conspiracy among climate change researchers to commit fraud, that indicate any destruction of data.
What about the references to “cleaning up” data? Does that amount to destruction?
No. In some cases there’s been intentional misrepresentation of what people were talking about in the e-mail exchanges. Nature had an editorial [December 3, 2009] where they basically came out and said that the attackers of climate change had misrepresented two statements. One was about a “trick,” which was simply a reference to a clever mathematical approach to a problem, the way scientists use the term trick: “Here’s the trick to solving that problem,” or “trick of the trade,” and so on. And then conflating that with an unfortunately poorly worded phrase where Phil Jones refers to hiding a decline in temperatures. Much hay has been made of that. But these are internal discussions among scientists who understand the lingo and understand what it means and understand the context. And it’s extremely easy for those looking to make mischief to take single words and phrases out of context.
Judith Curry has been an outspoken critic of your work and of a lot of climate researchers in general.
Did you ask Judith to turn over her e-mails from the past three years? Once she does that, then she’s in a position to judge other scientists. Until she does that, she is not in a position to be talking about other scientists. Glass houses. Look, I’ll just say this. I’ve received e-mails from Judith that she would not want to be made public.
She said that some data discussed in these e-mails concerned a temperature bump in the 1930s and 1940s, caused by a coincidence of Atlantic and Pacific decadal oscillations.
Yeah, I came up with the term: Atlantic Multidecadal Oscillation. I coined the term in an interview with Richard Kerr [a writer for Science] in 2000 over a paper with Tom Delworth of the Geophysical Fluid Dynamics Laboratory and the NOAA Laboratory in Princeton, where we actually were the ones to articulate the existence of this oscillation. And you know what? It was celebrated by contrarians. My work has been celebrated by climate skeptics. It’s an interesting footnote.
Is Curry wrong in that regard?
I don’t know exactly what she is referring to. She might be referring to a paper by Thompson et al. that appeared in Naturea couple of years ago about a spurious cooling in the 1940s that scientists couldn’t quite understand.
She was referring to a rise and fall in temperatures in the 1930s and ’40s that might have been caused by a coincidence of these oscillations in the Atlantic and Pacific, and another that could account for a lot of the warming in the 1990s. She was saying that it looked bad that you were trying to smooth out the bump in the ’30s and ’40s but not the one in the 1990s. Is that a valid critique?
The way you characterize it, it sounds like nonsense. I’m not sure how much familiarity she has, for example, with time-series smoothing. I’ve published a number of papers on this topic, and in fact, the approach that I take was used in the most recent IPCC report. I actually take a very objective approach to the problem of time-series smoothing. I’m not sure she understands the problem. It is very much the mainstream view in the climate research community that you cannot explain the warming of the past few decades without anthropogenic and human influences on climate.
If Phil Jones was being inundated by requests for data, why didn’t he just post everything on the Web for all to see?
It is very much my practice and the practice of all the scientists I know, at least now, under the sort of criticisms that were made 10 years ago about data archiving policies, to make available every scrap of data that we use in our studies that we are legally permitted to make available. With the Climatic Research Unit’s situation, what you have here is much [less] nefarious than it sounds. The Climatic Research Unit had legal agreements with certain countries that allowed them to use thermometer measurements, but they were legally bound not to distribute the data. The FOIA requests were demands for them to release those data, which they were legally bound not to release. The requests were disingenuous, and they were denied.
But all the rest of the data were released?
Yeah. The irony is that the data that they weren’t releasing made no difference to the results.
The National Academy of Sciences supported the key point of your hockey stick calculation, which showed higher temperatures in the 20th century than in the previous thousand years, but others criticized you for not releasing the information behind it. Is all that data now in the public domain?
It is. And it was released as soon as we were allowed to do so. I don’t produce any data myself. I just make use of other people’s data. Often scientists in a purely collegial spirit will make available to you data that they haven’t published yet. If you use it, you can’t distribute it. Every single piece of data that we had the right to distribute was available at the time that we published the paper. Once we had permission to publish the smaller number of other records that we hadn’t been able to make available at the time, those were out there.
By May 2000 all of the data were available. All of the claims that our data were not available at the time—by, for example, McIntyre, who’s been leading these attacks—are entirely false.
Many scientists were dismayed by the climate talks in Copenhagen. What was your reaction?
There are people in the policy world who would like to see action taken much more quickly, and there are some objective, scientific arguments for that. If we can stabilize CO2 concentrations at 450 parts per million, it gives us probably at least 2 degrees of warming. Some people feel that any more than that and we’ll really start to see the most threatening impacts of climate change. That requires essentially immediate action to slow down emissions and bring them to a peak, then start bringing them down fairly quickly over the next 50 years.
Were you disappointed at the lack of action?
I try to approach this from a scientific point of view. My understanding of the science does lead me, personally, to believe that certain policy options are better than others. But the policy in no way influences my science, and I think that’s the way it should be.
Public opinion, at least in this country, has shifted toward the skeptical.
It has moved in that direction.
What should scientists do about that?
Right now, there’s the largest disconnect that has ever existed between the confidence that we have scientifically and where the public is, at least in the United States. With each passing year, we’ve got more observations. We’ve got a better assessment of what’s happening now in the perspective of what happened in the past, so we can better determine if there are climate trends that are unusual. We have more information about how the system is evolving in response to human impact. We also have supercomputers that are much more powerful. The models we run now produce El Niño events just like they occur in nature. The models are getting better. The science is getting more certain.
Even as the science becomes progressively more certain, the public discourse goes through these cycles. We’ve had the reverse of the perfect storm we had back in 2006. Some people say climate change became too closely associated with a partisan political figure and that polarized the debate. We’ve had a cold winter. We’ve got a bad economy. It’s a bad time to be talking about major changes in our energy economy that some argue could be costly.
The biggest bludgeon the skeptics have is that there is uncertainty in the science. Should you and your colleagues be making more of an effort to quantify that uncertainty?
We’ve reached a point now in the interdisciplinary growth of our science where we’ve got climate scientists, who understand the physics of climate and how that translates to uncertainties, working hand in hand with economists who will run the projected impacts through a cost-benefit analysis. The way it plays out is that the small probability of extremely bad things happening incurs huge potential costs, and you want to hedge against those potential catastrophic costs. So when you take uncertainty into account, it actually leads to the decision that we should take action more quickly.
What is the worst-case scenario? Are we talking about the risk of our demise as a species?
That’s what scares me, yeah. Now it appears that the antiscience side is in a much better position from a public relations point of view than the scientific community is. I see nothing to change that dynamic. The way our system works, it almost ensures that as an environmental threat grows, there is an institution in place that acts in a way to thwart the attempt by civilization to confront that threat. I fear that it isn’t just a short-term thing. If that is our future, I worry. I have a 4-year-old daughter, and I care about the world that she grows up in.
How do you do research in an environment that is so politicized?
It’s difficult. And needless to say, I’m not getting a lot of science done right now. Half my job involves defending myself against attacks.
Has the political polarization had a detrimental effect on progress in climate science?
It has. Here’s the most basic example: Scientists like to communicate by e-mail. It’s much more efficient. You can respond whenever you want. Scientists aren’t going to be doing that as much anymore. When you do write an e-mail, you’ll probably take twice as long because you want to make sure that every word can’t be cherry-picked and distorted. You’re second-guessing yourself at every stage and, sure, that slows everything down.