The Cascade Snowpack - a numbers game
A case of bad science getting publicized.
From the
Seattle Times:
How one number touched off big climate-change fight at UW
The number is eye-popping, and it was repeated so often it became gospel.
The snowpack in the Cascades, it was said, shrank by 50 percent in the last half-century. It's been presented as glaring evidence of the cost exacted by global warming — the drying up of a vital water source.
That statistic has been repeated in a government report, on environmental-advocacy Web sites and in media coverage. Seattle Mayor Greg Nickels recently mentioned it in a guest column in The Seattle Times.
Here's the problem: The number is dead wrong.
The debunking of this statistic, and the question of just how much the state's snowpack shrank, is stirring up a heated debate among the region's climate scientists.
On Monday, it escalated further when University of Washington researcher and State Climatologist Philip Mote stripped a colleague of his title as associate state climatologist, triggering concerns that scientific dissent is being quashed. Losing the title doesn't affect the man's employment at the UW.
The affair might be dismissed as a tempest in an ivory-tower teapot. But it comes at a time when the science of climate change is getting more attention from policy-makers and the public.
And some different numbers:
On one side, Mass, who is working with Albright, said they see only a small downward trend in Cascade Mountain snowpacks, perhaps 10 to 15 percent since the 1940s. The measurement can be exaggerated by starting during a time of high snowfall, in 1950, and ending at a time of low snowfall in the mid-1990s, Mass said. But snowfall has increased again in recent years, and there is little overall change in snowpack in the past 30 years, Mass said.
And:
In late February, professor Dennis Hartmann, chair of the UW Atmospheric Sciences Department, stepped in to referee. After a meeting with the researchers, Hartmann issued a statement saying that snowpack appears to have dropped 30 percent, and that warming in the future will likely affect snowpack, particularly at lower elevations.
Even the worst-case examples are still 20% less than the 50% initially quoted.
Reminds me of Otto von Bismarck's famous aphorism:
Laws are like sausages, it is better not to see them being made. We need to include Climate Science in that list...
Posted by DaveH at March 17, 2007 4:42 PM