Thursday, October 19, 2006

Local Effects of Climate Change and Screenings of An Inconvenient Truth

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Residents of the American Midwest will not witness directly the most dramatic effects of global warming in the century to come. Melting ice sheets, thawing permafrost, and enormous changes in ocean currents will greatly impact our lives, but we won’t have front row seats to watch them happen. Even so, projections by Professor Don Wuebbles and other UIUC atmospheric scientists suggest that by the year 2100 the climate of Illinois will differ greatly from what we experience today. If you’ve got plans to be around then, a visit to present day eastern Texas might be a good preview of what you’re in for.

If we do nothing to reduce the amount of carbon dioxide and other greenhouse gases we put into the atmosphere when we drive our cars and run our air conditioners, the best climate models predict a worldwide rise in average annual temperature of 2 to 11 degrees Fahrenheit by the end of this century. But climate models suggest that temperature changes in our area are likely to be more dramatic. That is, the Great Lakes region can expect a rise in average daily temperatures of 5 to 12 degrees in winter and 5 to 20 degrees in summer.

At first glance the projections for changes in precipitation over the next hundred years look a little less depressing, since current models suggest that the annual average amount of precipitation for Illinois is projected to remain more or less constant. But within that average are unfavorable changes in seasonal patterns of precipitation. Models predict an increase in average winter precipitation, and no change or a decrease in summer precipitation. This scenario leaves us with much drier conditions than we now experience, since increases in winter precipitation will not compensate for the drying effects of a warmer climate. Drier conditions, of course, mean more pressure on Midwestern aquifers and surface water, especially as it becomes necessary to irrigate corn

Evidence also suggests that Illinoisans of the twenty-second century are likely to face more frequent disruptive weather events than we do now. Projections indicate longer, more severe heat waves, both earlier and later in the season, and a greater likelihood of intense storms, including 24-hour, multi-day rains.

Of course such changes in climate would also entail complex, undesirable ecological changes too numerous to even sketch here. But if you call to mind a few of the pests that are currently kept in check by our long winter freezes—kudzu and Asian soybean rust among them—you can get a sense of the impact significantly warmer winters might have.

Am I beginning to sound like Al Gore? I guess it’s no coincidence, since it’s the return of his documentary on global warming to Champaign-Urbana that got me going on this topic.

Next week the University YMCA and the UIUC Environmental Council will host two free screenings of An Inconvenient Truth. Both screenings will take place on Tuesday, October 24th—the first at noon at the University YMCA and the second at 7:00 p.m. in the auditorium of the National Soybean Research Center [map] on Peabody Drive in Urbana. A discussion led by Bill Sullivan, Director of the UIUC Environmental Council will follow the evening screening.

On the chance that you won’t make it to the film, which is way more entertaining than you might expect, let me emphasize two of the most important points it makes. First, every reputable climate scientist in the world agrees that global warming is real, dangerous, and a result of human activity. Second, most experts agree that we can avoid the most serious consequences of global warming if we act now to reduce greenhouse emissions.