Global warming and your lawn

By David Steinkraus

Monday, September 13, 2004 1:03 AM CDT

by david steinkraus Journal Times Brian Stone Jr. is looking at the problem of global climate change not from high in the atmosphere but from the perspective where most of us live - in apartments and houses.

Stone, an assistant professor of urban and regional planning at the University of Wisconsin-Madison, believes that if we can cool cities, we can have a dramatic effect on the emission of greenhouse gases.

"If you think about cities, cities occupy less than 10 percent of the world area," he said. But they consume immense amounts of energy. Generating that energy requires burning large quantities of fossil fuels, and that releases large quantities of heat-trapping greenhouse gases into the air.

If we had aggressive tree planting programs and used more materials that reflected sunlight, we could reduce city temperatures by 4 or 5 degrees, he said. "If you do that, you can reduce energy consumption by a substantial amount."

"We can cool down cities, feasibly, over 10 to 20 years." Global warming would reverse only over the course of centuries, but cooling cities now could help abate the phenomenon, he said.

Cities already are called "urban heat islands" because they produce so much extra warmth, he said. They're typically 10 degrees warmer than the surrounding countryside.

White shingles would help to reduce energy use, and because we have to reshingle homes as a matter of routine maintenance, this is a change we could make gradually and without incurring extra cost, he said.

Over the last couple of years, Stone said, he's started to look at the best kind of development to eliminate the urban heat island effect. It's not a suburb.

An apartment building actually has less impact than a home on a one-acre lot because home construction requires the removal of so many trees and the installation of impervious material, such as concrete roads, that hold heat.

"The primary factor in warming is the lawn area," Stone said. If politically possible, it would be better for cities to reduce lot sizes and certainly reduce the area of land devoted to lawn, he said.

"It's actually probably better - and most people in Wisconsin may not want to hear this - if you surround cities with forest rather than farmland."

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