Cities getting hotter

More concrete, more steel, skyscrapers reconfiguring wind, less trees and soils loaded with asphalt and vehicles - all this leads to more heat trapped in cities.

This stored heat will only get worse with increased atmospheric carbon dioxide, says Mark McCarthy, lead author and a research scientist with the Climate Impacts team at the Met Office, the United Kingdom's weather service. The research finds that "urban areas are warming faster" than rural ones, in response to rising levels of carbon dioxide.

In a world with carbon dioxide concentrations of 645 ppm, cities such as Los Angeles; Tehran, Iran; and Delhi, India, will experience about three times as many hot nights than in one with half as much carbon dioxide.

Their models predict that urban daytime temperatures will rise by more than 5 degrees Fahrenheit in most parts of the world when carbon dioxide levels in the atmosphere reach 645 parts per million, a figure possible as early as 2050. By then, more than 68 percent of the world's population will reside within urban areas -- up from 50 percent in 2009.

Plan to check out that suburban land you almost thought of buying??