It's Getting Hot in Hurrr.

Although I'm sure that everyone has been feeling the heat lately, those of us in cities have most likely been hit harder by the heat wave. According to this article from the Science Channel blog, the urban island heat effect is the cause for the film of sweat covering the entire city. This effect is caused by the combined heat-trapping efforts of concrete, steel, and asphalt. All this, in addition to the heat producing air-conditioners, cars, trains, buses, people, pets, planes, people, and of course, PEOPLE. And increased heat isn't the only bad side to the urban island heat effect. Aquatic life is killed off by the runoff created by blacktop which flows into rivers. With aquatic life out of the way, algae are free to monopolise all the available resources in the water. However, this article proposes a few solutions. We could either make every skyscraper’s rooftop a miniature Secret Garden, or we could simply paint them white. According to Michael Reilly or Discovery News, this would reduce the urban greenhouse effect by 33% globally.
The reason rooftop gardens are proposed as a solution to this problem is because plants suck up carbon dioxide. What does that have to do with heat? Well, carbon dioxide is a heat reflecting gas. Any heat that tries to escape through it is just reflected back to the surface of the planet. This effect is called the greenhouse effect. Trapped heat in the atmosphere is causing a continual rise in the global temperature. Plants can help with this, as they use carbon dioxide for photosynthesis. Photosynthesis is the process plants use to make energy. It produces oxygen. Therefore, increasing the amount of vegetation globally would make for a better quality environment overall.
This article is quite valuable, because it provides possible solutions to a problem that affects not the inhabitants of cities everywhere, but the entire world. With more possible solutions, we can solve the urban island heat effect, and eventually the greenhouse effect as well.

http://blogs.discovery.com/good_idea/2010/06/its-too-darn-hot.html