سال انتشار: ۱۳۹۰
محل انتشار: پنجمین همایش تخصصی مهندسی محیط زیست
تعداد صفحات: ۱۷
Ladan Kazemi Rad – Academic Center for Educational, Culture and Research
Tooba Abedi – Academic Center for Educational, Culture and Research
Greenhouse gases (GHGs) are gases in atmosphere that absorb and emit radiation within the thermal infrared range. This process is the fundamental cause of the greenhouse effect. The major GHGs in our atmosphere are water vapor, carbon dioxide (CO2), methane (CH4), halocarbons and nitrous oxide (N2O). The most recent assessment report compiled by the IPCC observed that changes in atmospheric concentrations of greenhouse gases and aerosols, land cover and solar radiation alter the energy balance of the climate system and concluded that increases in anthropogenic GHGs concentrations is very likely to have caused most of the increases in global average temperature since the mid-20th century. Agriculture accounted10-12% of total global anthropogenic emissions of greenhouse gases in 2005.Agriculture releases to the atmosphere significant amounts of CO2, CH4, and N2O. CO2 is released largely from microbial decay or burning of plant litter and soil organic matter. CH4 is produced when organic materials decompose in oxygen-deprived conditions, notably from fermentative digestion by ruminant livestock, from stored manures, and from rice grown under flooded conditions. N2O is generated by the microbial transformation of nitrogen in soils and manures and is often enhanced where available nitrogen (N) exceeds plant requirements, especially under wet conditions. Agricultural GHGs fluxes are complex and heterogeneous, but the active management of agricultural systems offers possibilities for mitigation. Many of these mitigation opportunities use current technologies and can be implemented immediately. This paper describes the development of GHGs emissions from the agricultural sector and details agricultural practices that may mitigate GHGs.