Tuesday, August 19, 2008
The Secret Life of Nitrogen
Putting "the secret life of" in front of the title of your book topic or tv show is pretty trendy right now, so I figured I'd join in. Nitrogen, as part of the nitrogen cycle, is a little known player in both global warming and the formation of acid rain. Both the carbon and nitrogen cycles are extremely important biogeochemical processes. Carbon dioxide gets a lot of press nowadays, but you don't hear about nitrogen very much. An ecology professor I know likes to call nitrogen "carbon's ugly little step-sister" who nobody pays much attention to. While total anthropogenic (human caused) carbon dioxide emissions are significant (somewhere around 6 gigatons per year if I remember correctly), we still have not come close to the annual output by natural processes. Due to the enormous growth of agriculture, however, human contributions of nitrogen actually passed natural contributions back in the 1980's. That's pretty impressive. Unfortunately, as industrially fixed nitrogen (for fertilizer) cycles through the ecosystem, the resulting reactive forms of nitrogen can have a variety of effects including: increased acid rain which damages soils and plant life, an enhanced greenhouse effect (warming the atmosphere), interference with natural ozone forming processes which occur in the stratosphere, and increased smog in some areas. The burning of fossil fuels also contributes reactive forms of nitrogen to the ecosystem. So, for those of you concerned with carbon footprints (yours or our nation's), don't forget about carbon's neglected little sis, nitrogen.