Environmental Science: Who says Population laws don't work?

Samples from the Greenland ice sheet suggest the U.S. Clean Air Act had a clear effect on conditions in the earth’s atmosphere. Pictured is ice core drilling at Summit, Greenland, in 2007. (Photo : Joel Savarino / Laboratory of Glaciology and Geophysics of the Environment)

Samples from the Greenland ice sheet suggest the US Clean Air Act had a clear effect on conditions in the Earth's atmosphere.

You can read the full story here: Greenland Ice Cores show Impact of US Clean Air Act on Climate