Over recent years I have watched with astonishment as the issue of global warming -- essentially a scientific question -- has become increasingly politicized. If you want to find believers and deniers, you will discover them almost exclusively on the political left and right, respectively. For most people engaged in the debate, data is irrelevant.
There are three questions. 1) Is warming real? 2) Is it at least partly the result of human activities? 3) What should we do about it?
The first two questions are amenable to scientific analysis. The answer to the third question will involve politics and economics, which in turn will reference scientific predictions for the severity of climate change, violent weather, sea-level rise, and so on.
Let us admit immediately that all three questions are hard to answer with certainty -- global climate is horrendously difficult to model, with many variables and feedbacks -- and not all scientists agree on the answers. But this much is certain: An extremely broad international scientific consensus exists that the first two questions are answered in the affirmative. A less robust consensus suggests that the results of warming are potentially severe enough to warrant present action to diminish greenhouse gases.
Deniers are quick to say that, of course, climate scientists will come to those conclusions; their livelihood and research funding depend upon pumping up anxiety. And, to be fair, we should provide particular scrutiny to research funded, for example, by tobacco, pharmaceutical and energy companies with vested interests in outcomes; scientists, after all, are human. Increasingly, major scientific journals require authors to declare financial interests that might be relevant to their research.
As it turns out, I have a ringside seat for assessing vested interests among climate scientists. My daughter is a climate scientist of some repute, presently director of the deep ocean sample repository at Columbia University's Lamont-Doherty Earth Observatory. I'll address her most recent publication (Nature, 22 March) and the question of foregone conclusions tomorrow.