Chicago’s environment department will plant rooftop gardens on a number of municipal buildings in an effort to reduce heat and pollution, and it will encourage private companies to do the same. Dark-roofed buildings and miles of pavement absorb the sun’s heat and raise the city’s temperature by as much as four to six degrees. The city’s new effort, part of an EPA program, is designed to help cut down on the city’s heat and thus on the electricity needed to run air-conditioning equipment. The city also plans to plant trees and other vegetation on medians to help cool pavement, and it may use lighter-colored paving surfaces.

Grist thanks its sponsors. Become one.