Global climate change causes heat waves. Really.

The six-day heat wave in Chicago finally broke Wednesday night, giving us delightful summer weather yesterday, but another heat wave is coming. We don't know when, of course; but it's looking more certain that human-caused climate change will give us more frequent and more severe weather events:

While it is impossible to attribute any one weather event to climate change, several recent studies suggest that human-generated emissions of heat-trapping gases have produced both higher overall temperatures and greater weather variability, which raise the odds of longer, more intense heat waves.

Last week, Paul Della-Marta, a researcher at Switzerland's Federal Office of Meteorology and Climatology, presented findings at an international conference on climate science in Gwatt, Switzerland, showing that since 1880 the duration of heat waves in Western Europe has doubled and the number of unusually hot days in the region has nearly tripled.

Fortunately, fewer than 900 days remain in the Bush Administration, but those days include two more summers plus what's left of this one.