Princeton physicist Freeman Dyson has been roundly criticized for insisting global warming is not an urgent problem, with many climate scientists dismissing him as woefully ill-informed. In an interview with Yale Environment 360, Dyson explains his iconoclastic views and why he believes they have stirred such controversy.
On March 3, The New York Times Magazine created a major flap in the climate-change community by running a cover story on the theoretical physicist Freeman Dyson that focused largely on his views of human-induced global warming.
Basically, he doesn't buy it. The climate models used to forecast what will happen as we continue to pump CO2 into the atmosphere are unreliable, Dyson claims, and so, therefore, are the projections. In an interview with Yale Environment 360, his first since the Times article appeared, Dyson contends that since carbon dioxide is good for plants, a warmer planet could be a very good thing. And if CO2 does get to be a problem, Dyson believes we can just do some genetic engineering to create a new species of super-tree that can suck up the excess.
These sorts of arguments are advanced routinely by climate-change skeptics, and dismissed just as routinely by those who work in the field as clueless at best and deliberately misleading at worst. Dyson is harder to dismiss, though, in part because of his brilliance. He's on the faculty at the Institute for Advanced Study, where as a young physicist he hobnobbed with Albert Einstein. When Julian Schwinger, Sin-Itiro Tomonaga and Richard Feynman shared the 1965 Nobel Prize in physics for quantum electrodynamics, Dyson was widely acknowledged to be almost equally deserving - but the Nobel Committee only gives out three prizes for a given discovery.
Nevertheless, large numbers of climate modelers and others who actually work on climate change - as Dyson does not - rolled their collective eyes at assertions they consider appallingly ill-informed. In his interview with Yale Environment 360, Dyson also makes numerous assertions of fact - from his claim that warming today is largely confined to the Arctic to his contention that human activities are not primarily responsible for rising global temperatures - that climate scientists say are flat-out wrong.
Many climate scientists were especially distressed that the Times gave his views such prominence. Even worse, when the profile's author, Nicholas Dawidoff, was asked on NPR's "On The Media" whether it mattered if Dyson was right or wrong in his views, Dawidoff answered, "Oh, absolutely not. I don't care what he thinks. I have no investment in what he thinks. I'm just interested in how he thinks and the depth and the singularity of his point of view."
This is, to put it bluntly, bizarre. It matters a great deal whether he's right or wrong, given that his views have been trumpeted in such a prominent forum with essentially no challenge. So I visited Dyson in his Princeton office in May to probe a little deeper into his views on climate change.
Yale Environment 360: First of all, was that article substantially accurate about your views?
Freeman Dyson: It's difficult to say, "Yes" or "No." It was reasonably accurate on details, because they did send a fact-checker. So I was able to correct the worst mistakes. But what I could not correct was the general emphasis of the thing. He had his agenda. Obviously he wanted to write a piece about global warming and I was just the instrument for that, and I am not so much interested in global warming. He portrayed me as sort of obsessed with the subject, which I am definitely not. To me it is a very small part of my life. I don't claim to be an expert. I never did. I simply find that a lot of these claims that experts are making are absurd. Not that I know better, but I know a few things. My objections to the global warming propaganda are not so much over the technical facts, about which I do not know much, but it's rather against the way those people behave and the kind of intolerance to criticism that a lot of them have. I think that's what upsets me.
e360: So it's a sense you get from the way the argument is conducted that it's not being done in an honest way.
Dyson: I think the difference between me and most of the experts is that I think I have a much wider view of the whole subject. I was involved in climate studies seriously about 30 years ago. That's how I got interested. There was an outfit called the Institute for Energy Analysis at Oak Ridge. I visited Oak Ridge many times, and worked with those people, and I thought they were excellent. And the beauty of it was that it was multi-disciplinary. There were experts not just on hydrodynamics of the atmosphere, which of course is important, but also experts on vegetation, on soil, on trees, and so it was sort of half biological and half physics. And I felt that was a very good balance.
And there you got a very strong feeling for how uncertain the whole business is, that the five reservoirs of carbon all are in close contact - then atmosphere, the upper level of the ocean, the land vegetation, the topsoil, and the fossil fuels. They are all about equal in size. They all interact with each other strongly. So you can't understand any of them unless you understand all of them. Essentially that was the conclusion. It's a problem of very complicated ecology, and to isolate the atmosphere and the ocean just as a hydrodynamics problem makes no sense.
Thirty years ago, there was a sort of a political split between the Oak Ridge community, which included biology, and people who were doing these fluid dynamics models, which don't include biology. They got the lion's share of money and attention. And since then, this group of pure modeling experts has become dominant.
I got out of the field then. I didn't like the way it was going. It left me with a bad taste.
Syukuro Manabe, right here in Princeton, was the first person who did climate models with enhanced carbon dioxide and they were excellent models. And he used to say very firmly that these models are very good tools for understanding climate, but they are not good tools for predicting climate. I think that's absolutely right. They are models, but they don't pretend to be the real world. They are purely fluid dynamics. You can learn a lot from them, but you cannot learn what's going to happen 10 years from now.
What's wrong with the models. I mean, I haven't examined them in detail, (but) I know roughly what's in them. And the basic problem is that in the case of climate, very small structures, like clouds, dominate. And you cannot model them in any realistic way. They are far too small and too diverse.
So they say, 'We represent cloudiness by a parameter,' but I call it a fudge factor. So then you have a formula, which tells you if you have so much cloudiness and so much humidity, and so much temperature, and so much pressure, what will be the result... But if you are using it for a different climate, when you have twice as much carbon dioxide, there is no guarantee that that's right. There is no way to test it.
We know that plants do react very strongly to enhanced carbon dioxide. At Oak Ridge, they did lots of experiments with enhanced carbon dioxide and it has a drastic effect on plants because it is the main food source for the plants... So if you change the carbon dioxide drastically by a factor of two, the whole behavior of the plant is different. Anyway, that's so typical of the things they ignore. They are totally missing the biological side, which is probably more than half of the real system.
e360: Do you think it's because they don't consider it important, or they just don't know how to model it?
Dyson: Well, both. I mean it's a fact that they don't know how to model it. And the question is, how does it happen that they end up believing their models? But I have seen that happen in many fields. You sit in front of a computer screen for 10 years and you start to think of your model as being real. It is also true that the whole livelihood of all these people depends on people being scared. Really, just psychologically, it would be very difficult for them to come out and say, "Don't worry, there isn't a problem." It's sort of natural, since their whole life depends on it being a problem. I don't say that they're dishonest. But I think it's just a normal human reaction. It's true of the military also. They always magnify the threat. Not because they are dishonest; they really believe that there is a threat and it is their job to take care of it. I think it's the same as the climate community, that they do in a way have a tremendous vested interest in the problem being taken more seriously than it is.
e360: When I wrote my first story about this in 1987, I had to say this is all theoretical, we haven't actually detected any signal of climate change. Now, people point to all sorts of signals, which are just the sort of things that were being predicted, based in part on the models. They made predictions and they've tested the predictions by seeing what happened in the real world, and they seem to be at least in the same direction, and in about the same magnitude, they were predicting. So isn't that a hint that there is something right about the models?
Dyson: Of course. No doubt that warming is happening. I don't think it is correct to say "global," but certainly warming is happening. I have been to Greenland a year ago and saw it for myself. And that's where the warming is most extreme. And it's spectacular, no doubt about it. And glaciers are shrinking and so on.
But, there are all sorts of things that are not said, which decreases my feeling of alarm. First of all, the people in Greenland love it. They tell you it's made their lives a lot easier. They hope it continues. I am not saying none of these consequences are happening. I am just questioning whether they are harmful.
There's a lot made out of the people who died in heat waves. And there is no doubt that we have heat waves and people die. What they don't say is actually five times as many people die of cold in winters as die of heat in summer. And it is also true that more of the warming happens in winter than in summer. So, if anything, it's heavily favorable as far as that goes. It certainly saves more lives in winter than it costs in summer.
So that kind of argument is never made. And I see a systematic bias in the way things are reported. Anything that looks bad is reported, and anything that looks good is not reported.
A lot of these things are not anything to do with human activities. Take the shrinking of glaciers, which certainly has been going on for 300 years and has been well documented. So it certainly wasn't due to human activities, most of the time. There's been a very strong warming, in fact, ever since the Little Ice Age, which was most intense in the 17th century. That certainly was not due to human activity.
And the most serious of almost all the problems is the rising sea level. But there again, we have no evidence that this is due to climate change. A good deal of evidence says it's not. I mean, we know that that's been going on for 12,000 years, and there's very doubtful arguments as to what's been happening in the last 50 years and (whether) human activities have been important. It's not clear whether it's been accelerating or not. But certainly, most of it is not due to human activities. So it would be a shame if we've made huge efforts to stop global warming and the sea continued to rise. That would be a tragedy. Sea level is a real problem, but we should be attacking it directly and not attacking the wrong problem.
e360: Another criticism that's been leveled is that your thoughts and predictions about the climate models are relatively unsophisticated, because you haven't been in close contact with the people who are doing them. But if you sit down and actually talk to the people about what goes into the models today and what they are thinking about and how they think about clouds, you might discover that your assumptions about what they are doing are not correct. Is that plausible? Do you think it might inform you better to actually sit down with these people and find out what they are doing today?
Dyson: Well, it depends on what you mean by sitting down with people. I do sit down with people. I don't go over their calculations in detail. But I think I understand pretty well the world they live in.
I guess one thing I don't want to do is to spend all my time arguing this business. I mean, I am not the person to do that. I have two great disadvantages. First of all, I am 85 years old. Obviously, I'm an old fuddy-duddy. So, I have no credibility.
And, secondly, I am not an expert, and that's not going to change. I am not going to make myself an expert. What I do think I have is a better judgment, maybe because I have lived a bit longer, and maybe because I've done other things. So I am fairly confident about my judgment, and I doubt whether that will change. But I am certainly willing to change my mind about details. And if they find any real evidence that global warming is doing harm, I would be impressed. That's the crucial point: I don't see the evidence...
And why should you imagine that the climate of the 18th century - what they call the pre-industrial climate - is somehow the best possible?
e360: I don't think people actually believe that. I think they believe it's the one during which our modern civilization arose. And that a rapid change to a different set of circumstances wouldn't be worse in a grand sense, but it would be very badly suited to the infrastructure that we have got.
Dyson: That's sort of what I would call part of the propaganda - to take for granted that any change is bad.
e360: It's more that any change is disruptive. You don't think that's reasonable?
Dyson: Well, disruptive is not the same as bad. A lot of disruptive things actually are good. That's the point. There's this sort of mindset that assumes any change is bad. You can call it disruptive or you can call it change. But it doesn't have to be bad.
e360: One thing is that if the temperature change projections are accurate for the next 100 years, it would be equivalent to the change that took us out of the last Ice Age into the present interglacial period, which is a very dramatic change.
Dyson: Yes, that's highly unlikely. But it's possible certainly.
e360: And the further argument is that this would happen much more quickly than that change happened. So it is hard to imagine that, at least in the short run, it could be anything but highly destructive.
Dyson: There's hidden assumptions there, which I question, that you can describe the climate by a single number. In the case of the Ice Age, that might be true, that it was cold everywhere. The ice was only in the northern regions, but it was also much colder at the equator in the Ice Age.
That's not true of this change in temperature today. The change that's now going on is very strongly concentrated in the Arctic. In fact in three respects, it's not global, which I think is very important. First of all, it is mainly in the Arctic. Secondly, it's mainly in the winter rather than summer. And thirdly, it's mainly in the night rather than at the daytime. In all three respects, the warming is happening where it is cold, not where it is hot.
e360: So, the idea is that the parts that are being disrupted are the parts that are inhospitable to begin with?
Dyson: Mostly. It is not 100 percent. But mostly they are, Greenland being a great example.
e360: Do you mind being thrust in the limelight of talking about this when it is not your main interest. You've suddenly become the poster child for global warming skepticism.
Dyson: Yes, it is definitely a tactical mistake to use somebody like me for that job, because I am so easily shot down. I'd much rather the job would be done by somebody who is young and a real expert. But unfortunately, those people don't come forward.
e360: Are there people who are knowledgeable about this topic who could do the job of pointing out what you see as the flaws?
Dyson: I am sure there are. But I don't know who they are.
I have a lot of friends who think the same way I do. But I am sorry to say that most of them are old, and most of them are not experts. My views are very widely shared.
Anyway, the ideal protagonist I am still looking for. So the answer to your question is, I will do the job if nobody else shows up, but I regard it as a duty rather than as a pleasure.
e360: Because it is important for you that people not take drastic actions about a problem that you are not convinced exists?
Dyson: Yes. And I feel very strongly that China and India getting rich is the most important thing that's going on in the world at present. That's a real revolution, that the center of gravity of the whole population of the world would be middle class, and that's a wonderful thing to happen. It would be a shame if we persuade them to stop that just for the sake of a problem that's not that serious.
And I'm happy every time I see that the Chinese and Indians make a strong statement about going ahead with burning coal. Because that's what it really depends on, is coal. They can't do without coal. We could, but they certainly can't.
So I think it is very important that they should not be under pressure. Luckily they are, in fact, pretty self-confident; (neither) of those countries pays too much attention to us.
But that's my motivation... Anyhow, I think we have probably said enough.
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