The Great Snowpocalypse

It has been snowing in Philadelphia—a lot. Since February 5, the city has had over 40 inches of snow from two blizzards in rapid succession. Just before Christmas, the city got nearly 24 inches. Altogether, the winter of 2009-2010 has set a new record for snowfall in the city, with just under six weeks until the official beginning of spring.

Philadelphia is not the only city with record snowfalls. Washington, DC, and other mid-Atlantic cities are also recovering from unprecedented blizzards. As I write this, the only state which has no snow anywhere within its borders is Hawaii. It has been a hard winter.

Climate skeptics, not surprisingly, are energized. They point to the blizzards of 2010 as further evidence that warnings about global warming are based, not on science, but on hysteria. One has only to look out the window to see that winter is still with us. Quod erat demonstrandum.

Not quite. Climate science does not provide a weather forecast for the next week. It is about long-term trends, not tomorrow's rainfall (or snowfall). And if science were simply about looking out one's window, all of us would still think the sun revolved around the earth.

What is more embarrassing for the skeptics—or should be—is that some climate scientists actually predict stronger winter storms for the northeastern United States. Writing in the New Republic, Bradford Plumer gives a good summary of the evidence.

Climate skeptics like Rep. Jim Inhofe (R-OK) will not be convinced by mere evidence. Inhofe believes climate science is a hoax and once cited a work of fiction (Michael Crichton's State of Fear) in support of his arguments to the House of Representatives.

Skeptics who are open to persuasion, however, can draw no comfort from the mounds of snow outside their windows. The consensus among climate scientists is that temperatures will rise—and they have; that glaciers will melt—and they have; and that weather patterns will change. Record snow in a city where blizzards are uncommon, like Philadelphia, may be evidence of a change in weather patterns. It may not. What it certainly does not show is that the scientific consensus is wrong.