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概述:It is known to all that the air pollution is detrimental to human health, but is there any benefits we can receive from these pollutants? Recently, researchers have discovered something that contravened our common sense.

Richard Harris
Natalie Mahowald
Cornell University
When we burn fossil fuels, we add carbon dioxide to the atmosphere and carbon dioxide contributes to global warming. But the world's smokestacks also emit pollutants that offset some of that warming. A new study shows that cleaning up air pollution could actually heat the planet more than scientists had previously thought. NPR's Richard Harris has this report. Power plants not only produce carbon dioxide, they spew soot, as well as compounds of nitrogen and sulfur and other stuff into the air. It's a complicated soup of material known as aerosols. And Natalie Mahowald at Cornell University says, so far, scientists have mostly tried to understand what those aerosols do while they're actually in the air. "There are so many different kinds of aerosols and they have many different sources, and some warm and some cool, but in the net, humans are emitting a lot of extra aerosols and it seems to be that they tend to cool for the most part." The aerosols reflect sunlight back into space or they stimulate clouds that keep us cool, but it turns out that's not all they do. Mahowald says these aerosols also influence how much carbon dioxide gets drawn out of the air by plants, on land and in the sea.