An interview with Freeman Dyson...

One of America's foremost scientists on climate change...

You write about the importance of "heretical thoughts" in the scientific community. What do you mean?

This is mostly about politics. In "A Many-Colored Glass" I came out of the closet as far as global warming is concerned. I believe global warming is grossly exaggerated as a problem. It's a real problem, but it's nothing like as serious as people are led to believe. The idea that global warming is the most important problem facing the world is total nonsense and is doing a lot of harm. It distracts people's attention from much more serious problems. That's an example. It's not so much to do about science. It's really a political question.

Why did you choose to be heretical about climate change?

I'm heretical because I was in the business of studying climate change at least 30 years ago before it became fashionable. I used to go to Oak Ridge National Laboratory [in Tennessee], which was then the leading place for studying it, and they had a very good group of people there. I went there regularly and wrote a paper, which was published, essentially about the connection between climate and vegetation. It was amazing how little we knew, and that's still true. It's just very interesting that, scientifically, almost all the statements that are made publicly are wrong.

We have no reason to think that climate change is harmful if you look at the world as a whole. Most places, in fact, are better off being warmer than being colder. And historically, the really bad times for the environment and for people have been the cold periods rather than the warm periods. The fact that the climate is getting warmer doesn't scare me at all. There's no reason why one should be scared. The economic conditions in the world and the technology change much more rapidly than the climate, so I don't see any reason for being in a hurry.

There's a huge movement among scientists and policymakers making the case that global warming is urgent. Have you publicly debated any of them?

It's not very helpful. True believers are not going to change their minds just because of me.

Why do you believe they feel so strong about the issue? Do you think they misconstrue the science?

I think it's a combination of things. Take Al Gore, who is sort of the chief propagandist. I think for him it really is a religion. He has this unshakable belief that it's his mission to spread the gospel of global warming according to Al. So there's nothing I can do about that. His film is a brilliant piece of work. It looks wonderful when you see it. The fact is of course that the pictures don't actually prove what he's saying is true.

Can you give an example?

A polar bear sitting on a melting piece of ice. The poor bear is going to drown, and it's a tear-jerker. But in fact, the bears are doing very well. The numbers of bears in the Arctic are increasing rather than decreasing. On the whole, they like it to be warm.

Just because you see pictures of glaciers falling into the ocean doesn't mean anything bad is happening. This is something that happens all the time. It's part of the natural cycle of things. We know from measurements that glaciers have been melting for 200 years at least. So it's certainly long before human activities could have caused it.

What we also know, going back 4,000 years, is that the glaciers were actually a lot smaller. They actually grew in the meantime. So it seems to be some sort of cyclical process. They grow and shrink and there's no particular reason for being worried just because they're shrinking at the moment. I'm not saying there's no climate change. Of course there's climate change. Climate change is part of the normal order of things, and we know it was happening before humans came. There is also human-induced climate change. That's certainly happening too. But I don't think there's reason for worrying about it.

So climate change has been politicized?

There is this very strong organization, the IPCC, the Intergovernmental Panel on Climate Change. It's a group of officially anointed experts who produce statements every five years. This community of people is regarded as sacrosanct. And they're very intolerant. They always regard any criticism as a hostile act that has to be fought. I think they have behaved pretty badly. But that's rather an unusual case in the world of science -- that's where the politics has corrupted the science. But in general, scientists are not largely against heretics. This is something rather peculiar to climate studies. It also has to do with the way [the studies are] funded. The whole community of climate experts is funded on the basis that it's an urgent problem. So [they] can't possibly say it's not urgent or else they'll lose their thumbs.