Freeman Dyson And The Climate Debate

Freeman Dyson is a brilliant, iconoclastic physicist. In 1985 he was invited to give the Gifford Lectures. Dyson's lectures are collected in a book, "Infinite In All Directions" online here.  I discussed Dyson's description of Natural Theology and the conflict between science and religion, in an earlier post.


Dyson makes two interesting arguments that bear on the Great Climate Debate, which had not fully erupted when he wrote "Infinite in All Directions."

Decades ago, before warming was the Big Problem, Nuclear winter was one of the issues that sat front stage. In addition to horrible death and destruction, nuclear winter was proposed as an indirect consequence of nuclear war. The theory proposed that if there was any substantial nuclear exchange, not even the Armageddon that many feared. particulate matter from burning cities would enter the atmosphere, block sunlight, cool the planet and produce a new glacial age.

Carl Sagan, probably the best known popularizer of science took up the cause. This created a dilemma for Dyson. He says that idea of nuclear winter:

... put professional scientists like me into an awkward position. On the one hand, the professional duty of a scientist confronted with a new and exciting theory is to try to prove it wrong. That is the way science works. That is the way science stays honest. Every new theory has to fight for its existence against intense and often bitter criticism.

As a scientist I want to rip the theory of nuclear winter apart, but as a human being I want to believe it. This is one of the rare instances of a genuine conflict between the demands of science and the demands of humanity. As a scientist, I judge the nuclear winter theory to be a sloppy piece of work, full of gaps and unjustified assumptions. As a human being, I hope fervently that it is right. Here is a real and uncomfortable dilemma. What does a scientist do when science and humanity pull in opposite directions?

The majority of scientists who have doubts about nuclear winter keep their doubts private. This is the third response to the dilemma, to say, it will not do us any good in the long run to believe a wrong theory, but it will not do us any good in the short run to attack it publicly, so let us keep silent and reserve judgment until the facts become clear. I myself have chosen the third response. It is an unheroic compromise, but I prefer it to either of the simple alternatives. The dilemma is similar to the dilemmas which occur frequently in personal and family life, when the demands of honesty and of friendship pull in opposite directions. It is good to be honest but it is often better to remain silent.

I think that the same thing may have happened with the climate debate. The things that are proposed to solve   climate problems--conservation, green energy, lower dependence on fossil fuels and especially on foreign oil, care of the environment--are all Good Things. Those proposing that anthropogenically generated warming is a reality are motivated to speak loud and long about the rightness of their cause. Those who have doubts keep silent--first for the same reason that Dyson kept silent on nuclear winter, and later for fear of the attacks that have been levied on scientists who have raised doubts about the "scientific consensus."

Whoever is right on the subject, these attacks go wholly against the spirit of science as I understand it. To quote Dyson again:

The ethic of science is supposed to be based on a fundamental open-mindedness, a willingness to subject every belief and every theory to analytical scrutiny and experimental test. The Royal Society of London in 1660 proudly took as its motto the phrase Nullius in Verba, meaning "No man's word shall be final."

Dyson seems to have learned from his earlier experience and has come out as one of the growing number of high-profile, well respected scientists who are questioning the scientific orthodoxy. I think that some of his statements are intended to be provocative, but most of them are well reasoned.