Global Nitrogen Overload Problem Grows Critical

Like a satiated gourmand, the biosphere is becoming glutted with nitrogen compounds. As early as the 1960s, researchers knew that some lakes and rivers were suffering because they were being overdosed with synthetic nitrogen fertilizers and nitrogen oxides discharged by cars and factories. But now, ecologists say, a surfeit of fixed nitrogen, by which they mean compounds such as ammonia and nitrogen oxides, is overwhelming entire ecosystems ranging from forests to coastal waters.