Hier finden Sie wissenschaftliche Publikationen aus den Fraunhofer-Instituten.

Mitigation options for methane emissions from rice fields

: Neue, H.U.; Wassmann, R.; Lantin, R.S.

Peng, S.; Ingram, K.T.; Neue, H.U.; Ziska, L.H. ; International Rice Research Institute -IRRI-:
Climate change and rice. Papers from a symposium
Berlin: Springer, 1995
ISBN: 3-540-58906-6
Symposium Climate Change and Rice <1994>
Fraunhofer IFU; 2002 in Helmholtz-Gesellschaft integriert

Recent estimates of global CH4 emissions provide a fairly good overall balance between sources, sinks and atmospheric accumulation of CH4: but global emission rates from many individual sources, including rice fields, are still quite uncertain. The global growth rate of the atmospheric concentration of CH4 has slowed during recent years from 20 ppbv/year (about 1.3 per cent per year) in the late 1970s to a rate of about 13 ppbv (about 0.75 per cent per year) in 1989 (IPCC 1992) and 4.7 ppbv in 1992. The Northern Hemisphere trend for 1992 is 1.8 ppbv and the Southern Hemisphere trend is 7.7 ppbv (Dlugokencky et al. 1994). It is not known whether the declining growth rate is due to decreasing emissions or increasing oxidation of CH4. More information and mechanistic understanding of fluxes of CH4 from individual sources and the fate of CH4 in the atmosphere are needed to reduce uncertainties of current and future emission estimates. Projected global population levels indicate that the de mand for rice will increase by 65 per cent over the next 30 years, from 460 million t/year today to 760 million t/year in 2020 (IRRI 1989). The growing demand must be met by intensified rice production on the existing 144 million ha of harvested riceland, especially in the irrigated and rainfed rice ecologies of Asia. This will most likely increase CH4 fluxes from wetland rice fields if current technologies continue. Regardless of uncertainties in global emission rates from rice fields, the achieved understanding of factors and processes controlling CH4 fluxes provides various technical opportunities to mitigate emissions without reducing the production potentials of rice.