I don't happen to have a settled view on global warming, but there's an instructive contrast to be observed in the following three discussions of the topic.

Here is Nicholas Kristof in this morning's New York Times, arguing that global warming is an imminent threat that demands immediate action. [Sorry, I just noticed that The Times now requires a paying subscription for this material.]

Here is a book review by astrophysicist Sallie Baliunas in Reason magazine contesting that claim.

And here is a piece on the BBC News website pouring cold water (sorry) on the supposed causal connection between global warming and the (supposed) increased frequency of intense hurricanes.

Two observations worth making on this:

First, whatever the truth of the matter, it is the skeptics in this case that have the better of the arguments. Kristof's piece is, by comparison with the Reason essay and BBC piece, a joke.

Second, note the global warming/Iraq connection as supplied by the concept of risk. Opponents of the Iraq war have typically argued that absent hard evidence of Iraqi WMD stockpiles, we had no business using force to disarm Iraq. In the present case, however, left-leaning environmentalists argue that absent hard evidence of danger, we're obliged to take drastic action.

This comes out vividly in this quotation from the Baliunas piece, one of many such quotations that one might cite:

Joining skeptics such as Patrick Michaels, who previously had published similar estimates of future warming trends, [NASA scientist James] Hansen said in 2003 that “emphasis on extreme scenarios may have been appropriate at one time, when the public and decision makers were relatively unaware of the global warming issue.…Now, however, the need is for demonstrably objective climate forcing scenarios consistent with what is realistic.”

Translation:"it might have been OK to deceive the public about global warming a few years ago, but now the game is up, so let's just tell the honest truth from here on out."

Hansen's"principle" here is an exact replica of the Bush Administration's strategy during 2002-2003 in discussing Iraqi WMD: emphasize extreme scenarios as a matter of consciousness-raising; then, when confronted with counter-evidence, ratchet things back and try haplessly to explain that the exaggerations, while exaggerated, did after all point to a real problem requiring a solution. Then pray that no one calls you on your squalid and stupid rhetorical manuever. Of course, if you are George Bush the Fundamentalist, your prayers will fail, and everyone will forever after say things like"Bush Lies--Soldiers Die." If you are an atheist environmentalist, on the other hand, your prayers will succeed and no one will notice your brazen manipulation of public opinion. Funny how that works.

Anyway, our environmentalists need to get their principles straight. Does weak evidence of a high-stakes event justify drastic action to prevent the event? I think it can--in both the Iraqi and global warming cases. But one can't have one's risk and eat it, too. One can't argue that 12 years of UN reports on Iraqi failure to disarm can be dismissed as"insufficient evidence of an imminent threat," while simultaneously insisting that weak evidence of global warming has to be played up so as to justify passing the Kyoto Treaty. Consistency: there oughta be a law.

Another question--or set of them. Can someone explain how the concept of"imminence" applies to global warming? Does warming present an"imminent danger"--whatever that means? Can we speak of an imminent danger in the absence of comprehensive evidence? I only ask because if the concept has such a transparent meaning in the context of warfare, it ought to have an equally transparent meaning in the context of environmental policy. And if it doesn't have a particularly clear meaning in the context of warfare, doesn't that mean that...well, I'll leave that thought and its ramifications as an exercise.