I thought this was interesting. Planners here in Chicago have used special satellite images to show which Chicago neighborhoods are the hottest. Literally, the hottest. Urban areas create a 'heat island' effect due to the black tar roofs and asphalt parking lots abundant in the city, which release hot blasts back into the surrounding environment. Vegetation, on the other hand, holds down temps by creating shade and evaporating water.
As it turns out, the study shows that tree cover is linked to lower temps, which makes sense. Those areas with the fewest trees and vegetation also were the most likely to exhibit the 'heat island' effect. The treeless (and hotter) areas were mapped and identified.
Using this, the planners are able to plan tree planting and development of vegetation-covered 'green roofs,' hopefully alleviating some of the heat in these neighborhoods. Pretty cool, I thought.