Archive for Sunday, July 23, 2006

Scientists: Get used to heat

Higher temperatures to have wide impact across the Midwest

July 23, 2006


— Last week's heat wave may have felt like something Midwesterners had never experienced before. But scientists are confident they'll get more chances to experience it again as climate change encourages more extreme weather.

Higher temperatures and more turbulent weather will affect everything in the Midwest - from what trees dot the landscape to what wildlife roams the region to what crops farmers raise to how cities allocate water.

Weather unpredictability would make dry years more common and wet years less effective for crop-growing. The result could be more reliance on crops such as dryland wheat and cotton and less reliance on corn and other rain-intensive crops.

But because the variables in the Midwest haven't been explored as deeply as on the more heavily populated coasts, the overall impact of global warming on Midwestern agriculture remains unclear, said Chuck Rice, a Kansas State University agronomist.

"In the middle part of the country, the (research) models aren't as good," he said.

While heat waves come and go, a gradual increase in Earth's atmospheric "greenhouse gases" is expected to make global weather more volatile over the next century, giving the Midwest more extremes like last week's 110-degree days.

The trend toward more severe weather could change the Midwest significantly in upcoming decades. And though government response has been quiet so far, those who study global warming say citizens and governments need to wake up to the problem now.

Alexis Kimberling, 4, plays in the splashpad Wednesday at Andrews Park, in Norman, Okla.

Alexis Kimberling, 4, plays in the splashpad Wednesday at Andrews Park, in Norman, Okla.

"We don't know exactly what's going to happen," said Randy Rogers, a state of Kansas fish and game biologist, "but the thing we can say with the greatest of confidence is, it's not going to be good."

Climate change created by global warming has concerned scientists for the past 20 years. Public attention to it has risen and fallen, often depending on the weather.

After years of bitter dispute over whether the world really is getting warmer, the scientific consensus is that it is. While some disagreement continues over how much of the warming comes from human activity and how much comes from natural climate trends, most scientists now agree that humans contribute significantly to global warming.

"It's unequivocal (that) the climate is changing," said Joel Scheraga, director of global change research at the U.S. Environmental Protection Agency.

That has put pressure on governments to come up with ways to deal with global warming before climate change is irreversible, a point that could come within 10 years.

Global warming varies by region, and different models predict different outcomes. Midwestern climate forecasts don't show as much change as in some other parts of the country.

Kansas' average temperature, for example, which increased 1.3 degrees in the past century, could in the next century increase by 2 more degrees in the spring, 3 in the summer and 4 in the fall and winter, according to one prediction. Rainfall isn't expected to change greatly.

Many global concerns, such as changing wind patterns or rising sea levels, aren't likely in the landlocked Midwest.

But that doesn't mean the Midwest won't change.

Higher temperatures mean more energy in the atmosphere. More energy means more turbulence. More turbulence means greater extremes, more heat waves, more snowstorms, more thunderstorms.

More tornadoes.

New water and weather patterns also will change Midwestern agriculture, both in what is grown and what consumers might pay in the store.

For consumers, climate change could conceivably lower food prices, as longer global growing seasons would create more productive farmland. That could hurt farmers, though, as food prices drop.

But the additional crops that could come from longer growing seasons and an increase in carbon dioxide may be exaggerated.

A Canadian study cited in the U.S. Agriculture Department's 2002 climate change report predicted that winter wheat yields under global warming could fall from 4 percent to 50 percent due to less-even rainfall, more frequent drought and potentially extreme temperatures. A University of Illinois study released last month that simulated the expected crop-growing atmosphere of 2050 found much smaller increases in the amount of crop produced per acre than expected.

What crops will be seen from Midwestern highways 50 years from now may still be in doubt, but the armadillos scurrying across them are already here, making their way north as America warms.

The lesser prairie chicken, for example, is growing less common in New Mexico and more common in Kansas, Rogers said. Should they continue north into Nebraska, he said, they could encounter habitat problems as they reach cropland.

While scientists warn that climate change needs to be limited as much as possible, public response has been lukewarm, though that, too, may be heating up.

The Bush administration has come under heavy fire from environmentalists, first for being slow to acknowledge climate change, then for being slow in implementing changes. Bill Wehrum, EPA's top clean air administrator, said administration efforts on climate change are "enormous."

The federal government plans to spend about $6 billion in climate-change projects this year, according to a report released last April. "We feel like we are providing very strong leadership on this issue," Wehrum said.


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