Science News: Waste heat from cars, power plants, and other fossil-fuel-burning machinery in the world’s largest urban areas can influence climate on a regional scale, and the “largest warming is not in the places where the energy is consumed.” This assessment comes from Ming Cai of Florida State University in Tallahassee and colleagues, in a study published online yesterday in Nature Climate Change. The researchers used computer simulations of 2006 energy use ifrom 86 of Earth’s largest cities and estimates of the waste heat emitted. Although the total amount of human-generated heat pales in comparison with that produced by the Sun, its influence on atmospheric circulation could raise temperatures by as much as 1 °C in northern Asia and North America, the researchers found.