Thursday, July 31, 2008

Heat Waves and Global Warming

As the extreme heat expands eastward over the next few days, the subject of global warming will, not doubt, get plenty of air time. How soon we forget the chilly spring of 2008, which put Midwestern flora two weeks behind schedule!

While there is plenty of evidence that Earth's climate is gradually warming, regional heat waves have no relationship to that global phenomenon. Rather, like other local weather patterns (e.g. the excessive snow and rain in the Upper Midwest), they are a product of ocean currents and jet stream patterns. Indeed, one area of extreme weather often lies adjacent to an area that is experiencing the opposite conditions (e.g. the coexistence of Midwest flooding and the Southeastern drought); such opposite extremes are usually separated by a persistent frontal boundary that, itself, is governed by a stable jet stream.

Once again, our short life spans and inability to take the long view make us jump to the wrong conclusions. We focus on current weather records (and assume that they forecast a climate meltdown) while overlooking the fact that the previous record occurred a century ago! Despite this mid summer heat wave (not terribly unusual) we could easily face record cold next winter. By then, thoughts of global warning will be suppressed (if not welcomed).