Monday, May 19, 2008

Dead in the water

It has been known for a long time that nitrogen in the water is, generally, a bad thing.

Nonetheless, every day large quantities of nitrogen run off from the fields of farms in Europe and America, and end up in the ocean causing vast areas to die off.

A couple of new papers in Science this week, document the effects of this nitrogen in the water and the air, and explain that reactive forms of nitrogen are being created at record rates and how this is cascading through the environment.

The story in The Economist looks at this problem and also talks about the idea of a nitrogen footprint, which is the amount of nitrogen produced by various activities, from beef farming to running a car. The green.view a few days later, picks up the story of the nitrogen footprint and looks at the various different footprints that exist (nitrogen, carbon, water and land) and at the concept that when products that require extensive use of these resources are traded, there is also a virtual trade.

For example, when beef is bought by Japan from America, there is also a trade of "virtual nitrogen" which is produced and emitted into the environment in America but on behalf of another country. An interesting paper which describes this idea in greater detail is Tip of the Pork Chop, last year in Ambio (see references).

The environment: Dead water
Too much nitrogen being washed into the sea is causing dead zones to spread alarmingly May 15th 2008

Green pedicure: Footprints in carbon, nitrogen and water

May 19th 2008 Web only

International trade in meat - The tip of the pork chop
Jim Galloway*, Marshall Burke, Eric Bradford*, Rosamond L. Naylor, Walter P. Falcon, Harold A. Mooney, Joanne Gaskell, Kirsten Oleson, Ellen McCollough, and others. Ambio, Vol. 36 no. 8, page(s) 622-629, December 2007.

Transformation of the Nitrogen Cycle: Recent Trends, Questions, and Potential Solutions
James N. Galloway, Alan R. Townsend, Jan Willem Erisman, Mateete Bekunda, Zucong Cai, John R. Freney, Luiz A. Martinelli, Sybil P. Seitzinger, and Mark A. Sutton (16 May 2008)
Science 320 (5878), 889. [DOI: 10.1126/science.1136674]

Impacts of Atmospheric Anthropogenic Nitrogen on the Open Ocean
R. A. Duce, J. LaRoche, K. Altieri, K. R. Arrigo, A. R. Baker, D. G. Capone, S. Cornell, F. Dentener, J. Galloway, R. S. Ganeshram, R. J. Geider, T. Jickells, M. M. Kuypers, R. Langlois, P. S. Liss, S. M. Liu, J. J. Middelburg, C. M. Moore, S. Nickovic, A. Oschlies, T. Pedersen, J. Prospero, R. Schlitzer, S. Seitzinger, L. L. Sorensen, M. Uematsu, O. Ulloa, M. Voss, B. Ward, and L. Zamora (16 May 2008)
Science 320 (5878), 893. [DOI: 10.1126/science.1150369]