Wednesday, February 28, 2007

Global Warming: Consensus vs. the Minority Reports

Patrick Michaels on global warming predictions:
The new estimate for maximum rise in sea level, assuming a middle-of-the-road estimate for carbon dioxide changes, is going to be lower than in previous IPCC reports. The last figure I saw was around 17 inches by 2100, down 40 percent from their previously estimated maximum.

A small, but very vocal, band of extremists have been hawking a doomsday scenario, in which Greenland suddenly melts, raising sea levels 12 feet or more by 2100. While this forecast enjoys no real support in the traditionally refereed scientific literature, it is repeated everywhere, and its supporters are already claiming that the IPCC -- the self-proclaimed "consensus of scientists" -- is now wrong because it has toned down its projections of doom and gloom.
It seems to me that global warming alarmists like Al Gore are playing both sides of the fence. On global warming’s existence, they emphasize the importance of scientific consensus and characterize the skeptical minority as equivalent to Holocaust deniers. But when it comes to global warming’s severity, they suddenly reject the scientific consensus and embrace a minority opinion. But they can’t have it both ways. If we are obliged to bow to the scientific consensus, then the minorities at both extremes should be treated with equal disdain.

For my part, I don’t think scientific consensus deserves unquestioning reverence; even smart and knowledgeable people are sometimes subject to groupthink and confirmation bias. So I’m willing to give a modicum of consideration to both the skeptics and the catastrophists, though in this case I think the consensus is probably about right (at least with respect to climatic as opposed to economic impacts). What really irks me is the inconsistency.


Anonymous said...

This is such a breath of fresh air. I've been struggling with this extreme debate for quite some time now, and I never seem to be able to find my way through the noise. Your dichotomy of existence v. severity makes perfect sense and places the debate within a more manageable framework for me.

I find the evidence of the existence of climate change virtually irrefutable (I enjoyed Gore's movie, btw), but I'm having a tougher time with the effect/severity question. Do you have a sense of which side of this part of the debate has the upper hand?

Glen Whitman said...

I'm having a tougher time with the effect/severity question. Do you have a sense of which side of this part of the debate has the upper hand?

The scientific consensus seems to be that sea levels will rise by about a foot or foot-and-a-half over the next 100 years. But in the popular debate, the catastrophist theory pushed by Al Gore and others seems to get more attention, perhaps because it's so much more dramatic.