Nitrogen: The Triple Whammy.

Nitrogen (reactive nitrogen, such as nitric acid, nitrous oxide, ammonia and nitrate not the inert nitrogen that makes up 80 percent of air), is currently not one of the six gases covered by the Kyoto Protocol. It is, however, teeing up to be another gas to contend with. Its impact is complex, it not only has a role in climate change as a gas that is used in manufacturing, it is also produced during decomposition, and, it has serious biological impacts through its presence in fertilizer use.

Nitrogen trifluoride, used in the production of semi conductors and liquid–crystal displays found in many electronics, according to an article in the Geophysical Research Letters, is about 17,000 times more powerful in causing global warming than carbon dioxide, and is not regulated under the Kyoto Protocols.  In fact, according the Letters, it currently, already, causes more global warming than coal fired power plants.

Reports have already pointed to the fact that nitrogen is likely to be increasingly emitted as the Arctic warms and the tundra’s permafrost thaws. The permafrost consists of frozen, partially decomposed plant material, which will decompose when the temperature warms releasing vast amounts of nitrogen and carbon into the atmosphere.

Finally, nitrogen fertilizer is responsible for the expanding ocean dead zones.  When an ecosystem has too much nitrogen, it first causes huge growth, but then turns against itself and becomes toxic, producing algal blooms in water bodies, killing all life.  The temptation, of course, is to over-fertilize to increase crop yields, but the excess leaches out into the water table and receiving waters, causing serious problems downstream.  Coastal rivers in the northeastern U.S. and northern Europe, for example, are receiving as much as 20 times the natural amount from both agricultural and airborne sources.  This level of nutrient surfeit threatens air and water quality, and the health of terrestrial and aquatic systems.  It can result in a decline in soil fertility, and significantly alter the structure of ecosystems.    Nitrogen containing gases – nitric oxide and nitrous oxide – also affect the health of the atmosphere when they are released into the air.  Nitric oxide is a precursor of smog and acid rain, and nitrous oxide is a long-lived greenhouse gas that traps some 200 times more heat than carbon dioxide.

This calls for more carefully calibrated use of nitrogen fertilizers, finding safe substitutes for nitrogen trifluoride in industrial manufacturing, and, curbing general green house gas emissions to avoid the thawing of the permafrost.

Sources: Vitousek et al. 1997 Human domination of Earth’s ecosystems. Science Vol 277: 494-499, World Resources Institute, Nutrient Overload: Unbalancing the Global Nitrogen Cycle, Morgan R., Beyond Carbon: scientists worry about nitrogen’s effects, NYTimes 09/02/08 D3, Prather and Hsu, NF3, the greenhouse gas missing from Kyotom Geophysical Research Letters Vol 35, l12810, doi:10.1029/2008GLO34542

Date Posted: 9/8/2008