During the first weeks of 2013, Tehran was often blanketed in a stagnant, brown layer of smog so thick and obtrusive that it was difficult to make out the conspicuous mountain ranges that encircle the city. After trying to regulate the number of cars on the streets, a measure that failed to reduce the noxious [...]

Soot may be responsible for the tropics expanding north, according to an analysis involving multiple computer models of the climate. By absorbing sunlight and trapping extra heat in the atmosphere, the tiny, black particles may be helping the poleward march of tropical conditions. The research will be published in Nature on May 17. (Scientific American [...]

The aftermath of burning a mountain of coal isn’t pretty. It’s not just the ash itself; it’s also the toxic elements that have been purified by fire out of the "fossilized sunshine." Those toxic elements come along for the ride when the coal ash spills, like it did near Kingston, Tenn., on December 22, 2008. [...]

Forty years ago today Republican president, Richard Nixon, created the Environmental Protection Agency. At the time the nation had no law mandating clean water, clean air or the safety of chemicals. Lead was still in all gasoline, and acid rain was poisoning the waterways downwind of the nation’s coal-burning power plants. Forty years later, we [...]

DENVER—Few human undertakings have had such apparent and ceaseless negative impacts on human health and well-being as violent conflict. War might seem such an obvious assault on overall public health that it would hardly bear discussion at a scholarly meeting on that subject. But a slew of researchers are working around the globe to uncover [...]