The science and politics of increasing nitrogen pollution from human activity : case study of the Aberjona watershed

The biogeochemical cycling of nitrogen has critical implications for all life on earth. The Haber-Bosch process (1909) paved the way for the industrial fixation of NH3 from unreactive atmospheric dinitrogen, a phenomenon previously restricted to the enzyme nitrogenase and to a lesser extent lightning. Perhaps the most profoundly catalytic invention of the 20th century, Haber-Bosch has greatly increased the global anthropogenic throughput of nitrogen that now rivals the 160 million metric tons fixed annually via nitrogenase. Notably 40% of the world's 6 billion people alive today owe their body's kilogram of nitrogen to synthetic fertilizer created via the Haber-Bosch process (Smil 2001). The intensification of agriculture and the growth of urban centers during the 20th century has also resulted in substantive increases in nitrogen loads to the environment. Nitrogen transported by surface and groundwater is ultimately concentrated in rivers and coastal areas, with consequences such as eutrophication and the "dead zones" of hypoxia found throughout the world. Microbial metabolism of nitrogen via the nitrification and denitrification pathways also produces N20, a potent greenhouse gas currently responsible for 5% of total atmospheric radiative forcing.

Department dc:contributor.department

Massachusetts Institute of Technology. Engineering Systems Division

Grantor dc:publisher

Massachusetts Institute of Technology

Year dc:date.issued

2006

Author dc:creator

• Orosz, Matthew S. (Matthew Sándor), 1977-

Advisor dc:contributor.advisor

• Harold F. Hemond.

• Technology and Policy Program.

Statement dc:rights

• M.I.T. theses are protected by copyright. They may be viewed from this source for any purpose, but reproduction or distribution in any format is prohibited without written permission. See provided URL for inquiries about permission.

Licence dc:rights.uri

• http://dspace.mit.edu/handle/1721.1/7582

Language dc:language.iso

eng

Handle dc:identifier.uri

http://hdl.handle.net/1721.1/35680

OAI identifier oai:identifier

oai:dspace.mit.edu:1721.1/35680