Newspaper article The Christian Science Monitor

Chicago Rooftops: From Gravel and Tar to Greenery as Part of a National Experiment, Windy City Uses Prairie Grass And

Newspaper article The Christian Science Monitor

Chicago Rooftops: From Gravel and Tar to Greenery as Part of a National Experiment, Windy City Uses Prairie Grass And

Article excerpt

From the elevated train rumbling through downtown Chicago, the view is a blur of black rooftops, wide expanses of parking lots, and a paucity of greenery. It is standard urban scenery to passengers, but to environmental experts, rooftops and pavement are the next frontier for combating smog and higher temperatures in cities.

So this spring, Chicago and four other US cities are participating in an experiment to transform the rooftops of America. Here along Lake Michigan, officials plan to plant gardens on the roofs of a handful of public buildings, which could mean a lovelier view for passengers on public trains. But more important, some environmental officials say covering dark, heat-absorbing roofs with prairie grasses, purple coneflowers, and other plants, will also will reduce air pollution and cool the city - cutting energy costs.

Rooftop gardens are good for urban environments because they absorb industrial emissions and reflect heat. "Basically, anything you can do to cover areas with vegetation, whether it's urban forestry, tree planting - you'll have a natural cooling effect," says Dennis Church, president of EcoIQ, an environmental consulting firm in Cupertino, Calif. For their part, the other cities involved in the program - Houston, Salt Lake City, Baton Rouge, La., and Sacramento, Calif. - are focusing on using lighter colored, energy-efficient roofing materials instead of roof gardens. Researchers at Lawrence Berkeley National Laboratory in California found in a study of buildings in Sacramento that those with lightly colored roofs used 40 percent less energy from air conditioning than those with darker roofs. With technical help from the US Environmental Protection Agency (EPA), environmental officials hope such programs will lessen the detrimental effects of "urban heat islands," a phenomenon in which city temperatures can rise six degrees higher than those in surrounding rural areas. Scientific research has shown that over the past 30 to 80 years, July's maximum temperatures in major cities worldwide, from Baltimore to Tokyo, have risen by as much as 1 degree per decade. …

Search by... Author
Show... All Results Primary Sources Peer-reviewed

Oops!

An unknown error has occurred. Please click the button below to reload the page. If the problem persists, please try again in a little while.