In an effort to fight global warming, rooftops should be given a new green look. By planting rooftop gardens on large structures, cities can use the sun to keep the city cooler instead of letting it heat things up. Large flat rooftops are ideal areas for these gardens.
Heat is usually absorbed by the rooftops of the city. The temperature in the cities are often 4 to 10 degrees(F) warmer than the surrounding countryside. This is the result of dark roofing and paving materials absorbing the summer sun's heat.
"Computer modelling predicts that widespread heat-reduction measures could easily lower a city's temperature five degrees," said Hashem Akbari, a researcher at Lawrence Berkeley National Laboratory in California.
'Chicago is planning rooftop gardens in an effort to cool the city and reduce smog'
Chicago is already planning to plant rooftop gardens in an effort to cool the city in the summer and reduce smog. Planting lawns, shrubs and trees with non-invasive root structures will provide a reflective barrier for the heat. It will also help improve the air quality of the area by absorbing carbon dioxide and by producing oxygen. Chicago presently violates federal air quality standards on a regular basis.
Hotter temperatures increase smog by forcing air conditioning units and electric plants to work harder and emit more pollution, city and EPA officials said. Pollution reacts with heat and sunlight to create smog.
Another result of rooftop gardens is an opportunity to lower stress in the workplace. Large office buildings with green roofs can provide a place for stressed out employees to unwind. A park at the top of the elevator would be a great place to take a lunch and to relax for a while away from the hustle of the city. These gardens also increase the habitat for many species of birds by providing more nesting area within the city.
Scott Rhoades (e-mail: email@example.com).
More recent news - rooftop gardens in Tokyo
Summarised from an article entitled 'New Tokyo buildings to have rooftop gardens' in the Seattle Times (10th December 2000). Monitored for the Institute by Roger Knights.
Owners of new buildings in Tokyo will be required to turn part of their rooftops into gardens as part of a new ruling by the city's metropolitan government. The law comes into effect in April 2001, and is aimed at combatting rising temperatures in Tokyo. It states that at least one-fifth of all available roof space should be covered by plants, and this will apply to buildings erected on more than 1,200 square yards of land. Any owners who do not comply could face fines of up to £1200.
In the last century, the average annual temeperature in Tokyo rose by 5.2 per cent, and last July was the third-hottest July on record. As a result of these statistics, the city government has decided to act, thus joining Germany, which remains the only country that has a similar rooftop requirement for developers.