I've been thinking about how to commemorate the 40th anniversary of Earth Day tomorrow. After considering a dozen topics I concluded that I could do no better than to direct your attention to a recent NY Times column by Paul Krugman, called Building a Green Economy. If you do nothing else to observe Earth Day, please read Krugman's article.
Addressing the arguments of scientists and skeptics, alike, Krugman's piece offers the clearest and most comprehensive explanation of the causes and effects of climate change, possible remedies, likely costs of mitigation - as well as likely costs of inaction, and rationale for action that I have read in a long time.
After citing the most current scientific evidence, Krugman writes
UNCERTAINTY MAKES THE MOST URGENT CASE FOR STRONG ACTION"models based on [this] research indicate that if we continue adding greenhouse gases to the atmosphere as we have, we will eventually face drastic changes in the climate. Let’s be clear. We’re not talking about a few more hot days in the summer and a bit less snow in the winter; we’re talking about massively disruptive events, like the transformation of the Southwestern United States into a permanent dust bowl over the next few decades.
Despite the high credibility of climate modelers, he concedes that there is still tremendous uncertainty in their long-term forecasts, which leads to his most original conclusion - that it is this very uncertainty that makes the most urgent case for strong action.
"You might think that this uncertainty weakens the case for action," he continues,but it actually strengthens it." Even if utter catastrophe is not the most likely outcome, the fact that there is a significant chance of catastrophe, which the science supports, acting on that chance — rather than what is most likely to happen — should dominate cost-benefit calculations.
Quoting Harvard professor, Martin Weitzman, Krugman emphasizes that it is
". . . this risk of catastrophe, rather than the details of cost-benefit calculations, [that] makes the most powerful case for strong climate policy. Current projections of global warming in the absence of action are just too close to the kinds of numbers associated with doomsday scenarios. It would be irresponsible — it’s tempting to say criminally irresponsible — not to step back from what could all too easily turn out to be the edge of a cliff.
During a heavy snow storm this winter, I blogged about how happy such weather must make climate change skeptics, who would have us believe that the continued existence of winter disputes the evidence that the planet is warming. Krugman also notes that "a snowy winter on the East Coast of the U.S. has given climate skeptics a field day, even though globally this has been one of the warmest winters on record."
But one heavy snowstorm isn't going to make this issue go away. There is a good chance, Krugman says, that record temperatures around the world this year will deprive climate skeptics of one of their main talking points, and that, "given the twists and turns of American politics in recent years — since 2005 the conventional wisdom has gone from permanent Republican domination to permanent Democratic domination to God knows what — there has to be a real chance that political support for action on climate change will revive.
"We know how to limit greenhouse-gas emissions," he concludes. "We have a good sense of the costs — and they’re manageable. All we need now is the political will."
Earth Day is a good time to muster that political will.

