We should never again assume that science alone is going to make the political difference on this issue, no matter how strong it gets.I was more than a little disappointed to read that. Chris is a smart guy, and he's been around science and politics for a long time. He should realize that while science can inform the policies we adopt, it can't determine them (see also this post and this one).
Policy decisions involve choices about the kind of world we want to live in. Science can tell us which worlds are possible. It can't tell us which are desirable.
Chris didn't refer to the recent Pew report on the public's priorities for 2010, but he could have. As you can see from the figure at the left, fewer than 3 in 10 of Americans regard dealing with global warming as a top priority, fewer than half regard the protecting the environment as a top priority, and fewer than half regard dealing with the energy problem as a top priority. It doesn't make any difference how solid the evidence is that human activities are contributing to an increase in global average temperature if the public and politicians don't care.
And the news is even worse than that.
Support for efforts to curb global warming, protect the environment, and provide energy solutions is substantially smaller now than it was three years ago when George W. Bush was still president. In 2007 almost 4 in 10 of those surveyed regarded curbing global warming as a top priority. Almost 6 in 10 said the same of protecting the environment and providing energy solutions. Those changes don't reflect changes in our understanding of the underlying science. They reflect a recalibration of priorities.
And what goes for climate science goes for any field of science producing policy-relevant results. Not only must we recognize what science contributes and distinguish those contributions from advocacy, but we must also support research that enhances our ability to make sure that decision makers consider scientific evidence appropriately when making their decisions.