(Sound effect: rain sounds) The Forecast: Sour Showers.
I'm Bob Karson with the discovery files--new advances in science and engineering from the National Science Foundation.
(Sound effect: single raindrops) Back in the 70s "acid rain" was a hot-button issue. After decades of industrial pollution, congress acted on scientific reports and passed the clean air act. (Sound effect: thunder, steady rain) By the 2000's, sulfate and nitrate content in rain dropped by 40 percent. But now the cloud with a silver lining is revealing a dark side.
(Sound effect: stream, forest sounds) At the National Science Foundation's Hubbard Brook Experimental Forest in New Hampshire--the very site where acid rain was first identified--scientists have found that, although it may be a result of different conditions, we could experience a future acid rain 'flashback.' Using sophisticated computer models of the site, they discovered that today's higher carbon dioxide levels are altering the water quality of forested watersheds--in much the same way as acid rain.
It's taken years for New England forests, lakes and streams to recover from the acidification caused by atmospheric pollution. Now scientists say these forests and streams are under threat again, as climate change likely returns them to an acidified state. They say the environmental implications are severe. Only this time, reversing the effects may be much more difficult.
It seems the reign of acid rain is far from over.
"The discovery files" covers projects funded by the government's national science foundation. Federally sponsored research--brought to you, by you! Learn more at nsf.gov or on our podcast.