Nitrogen Pollution (2003)

The Science Links Nitrogen project focused on nitrogen pollution. Many people don't realize that human activity has significantly altered the global nitrogen cycle. Through fossil fuel combustion, fertilizer production and use, and wastewater discharge, human activities release nitrogen into the air and water at greater levels than ever before. Though essential to plant growth, nitrogen can damage the environment at excessive levels. As excessive nitrogen moves through the landscape, it affects the ecological health of forests, soils, streams and, ultimately, coastal environments. This phenomenon of 'cascading effects' is familiar to ecologists, but warrants better public understanding. The public policy implications of nitrogen pollution are substantial, relating to the U.S. Clean Water Act, Clean Air Act and Farm Bill.