Monday, September 22, 2008

Global 'Active' Nitrogen Has Doubled


The Haber-Bosh industrial process, which allows the "mining" of inert nitrogen from Earth's atmosphere to make chemically active ammonia, won Nobel Prizes for its inventors and gave the world seemingly inexhaustible supplies of artificial plant fertilizers. But, on Friday, Sept. 19 , former Nicholas School Dean Bill Schlesinger tallied the down-side of this industrial age miracle in a seminar presentation at the Nicholas School of the Environment.

Displaying stark "before" and "after" slides drawn in part from his own research, the biogeochemist showed his Old Chemistry Hall audience that industrial fertilizer production has essentially doubled amounts of chemically active nitrogen in our planet's air, water and soils compared to volumes nature itself provides via phenomenon like plant nitrogen fixation and lightning strikes.

Some those extra teragrams (trillions of grams) are now fomenting marine life destroying algae blooms and "dead zones" along coastlines. Others are polluting underground water supplies beneath agricultural lands, leading in extreme cases to medical problems such as the "blue baby syndrome." And a byproduct of denitification, the process whereby bacteria can convert some of that chemically active nitrogen back to the inert form, can even contribute to global warming, he said.

Schlesinger is now president of the Cary Institute of Ecosystem Studies in Millbrook, N.Y.

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