Are our cities and towns contributing to the global warming? This is a question NASA researchers are trying to find an answer to. Preliminary research has shown that towns and cities are warmer than the surrounding rural areas.
Another factor under research is whether the location of the urban area makes a difference. It has been observed that the extent of warming in these “heat islands” is directly related to the kind of ecosystem they have replaced. Simply put, it means that a city replacing a forested area will generate more heat when compared to an urban area found in dry and semi dry areas.
Urban areas are warmer due to the fact that the percentage of impervious surfaces like concrete and asphalt is higher than the surrounding regions. The urban areas also lack vegetation in the form of adequate trees and green spaces.
Urban areas replacing desert like conditions bring in more vegetation and water surfaces than those found in the original ecosystem. Thus these pockets are cooler than the surrounding natural regions.
It is yet to be determined if this local generation of heat affects the overall global warming.