HR: 16:15h
AN: A54B-04    [Abstracts]
TI: Human and Animal Wastes: Implications for Atmospheric N2O and NOx
AU: * Wang, Y
EM: wang3@fas.harvard.edu
AF: Division of Engineering & Applied Science, and Department of Earth & Planetary Sciences, Harvard University , Pierce Hall, 29 Oxford St. , Cambridge, MA 02138 United States
AU: McElroy, M B
AF: Division of Engineering & Applied Science, and Department of Earth & Planetary Sciences, Harvard University , Pierce Hall, 29 Oxford St. , Cambridge, MA 02138 United States
AB: More than 220 TgN are processed annually through the global agriculture/animal/human food chain. It is suggested that aerobic denitrification, reduction of nitrite formed in the first stage of nitrification, is an important source not only of global N2O but also of NOx. A simple top-down method indicates a globally averaged yield of 2% for N2O emitted as a consequence of human disturbances to the global nitrogen cycle. This yield can account not only for the contemporary budget of atmospheric N2O but also for trends observed over the past 1000 years. The associated microbial source of NOx is estimated assuming a NOx/N2O ratio of 3, consistent with results from a variety of laboratory and field studies. This source is significant, particularly for large developing countries such as China and India for which its contribution is comparable to that from fossil fuel.
DE: 0322 Constituent sources and sinks
DE: 0330 Geochemical cycles
DE: 0365 Troposphere--composition and chemistry
SC: Atmospheric Sciences [A]
MN: 2005 Joint Assembly