Weathering the Pursuit of Climate Extremes

Article excerpt


There's a big drought on in the Eastern United States, especially from Northern Virginia to southern New England. In other words, the epicenter lies along the Washington-New York axis. Everyone knows what this means: a drought more important than any other weather event in world history.

The last time this region received a major weather whopper was the huge snowstorm of early January 1996. Of course, it was the most important snowstorm in history, and it prompted a cover of Newsweek, with the headline "Blizzards, floods and hurricanes: Blame global warming." The analogous cover for this drought, I predict, will appear in Time magazine within the next two months.

This is a very bad drought. New York's reservoirs are way down, during a time of the year in which they should be brimful. If conditions do not change in the next two months (and there's no real reason to expect them to), 2002 will rival 1930, which is the drought of record for the last century. (There are spotty records showing a much more extensive drought of four year's duration in the early 1850s in this region.)

If that comes to fruition, a tremendous amount of Eastern forest is likely to go up in smoke this summer. In 1930, 300,000 acres of Virginia forest burned, a figure that has never even been approached in the succeeding seven decades. Much of the Appalachian region was heavily logged in the late 19th century, so that the trees in 1930 were lot younger than they are now.

There's much more to burn this time, and the big ice storms of the 1990s have left an additional huge amount of fuel on the forest floor. Many times I have stopped along the Shenandoah Park's Skyline Drive and thought that this forest looks like hell about to break loose, just given enough heat and drought.

It was so dry in 1930 that the normally moist surface layer in the Mid-Atlantic turned to powder, allowing the sun's energy to concentrate exclusively on raising the temperature rather than evaporating water. As a result, many of the all-time-hot records hail from that summer. Given an extreme drought along with the extreme pavement growth of the Washington area, a temperature of 110 degrees Fahrenheit will not be out of the question in 2002. The rural record, set in July 1930, is 109 degrees.

As an antidote to what will certainly be over-hype in an already bad situation, perhaps a look at long-term trends in record warm and cold temperatures over the United States is in order. The reference for this is a 2001 paper in the journal "Climate Research," published by our research group at University of Virginia. …