Global greenhouse gas mitigation potential in agriculture

Agricultural lands occupy about 40-50 % of the Earth’s land surface. Agricultural practices can make a significant contribution at low cost to increasing soil carbon sinks, reducing GHG emissions, and contributing biomass feedstocks for energy use. Considering all gases, the global technical mitigation potential from agriculture (excluding fossil fuel offsets from biomass) by 2030 is estimated to be ~5500-6000 Mt CO2-eq. yr-1(Smith et al., 2007a&b; Smith et al., 2008). Economic potentials are estimated to be 1500-1600, 2500-2700, and 4000-4300 Mt CO2-eq. yr-1 at carbon prices of up to 20, 50 and 100 US $ t CO2-eq.-1, respectively About 70 % of the potential lies in non-OECD/EIT countries, 20 % in OECD countries and 10 % for EIT countries. In the long-term (post-2050), climate change may affect the mitigation potential of soil carbon sinks but the direction and magnitude of this effect is uncertain (Smith et al., 2007a&b; Smith et al., 2008). Agricultural mitigation options are cost competitive with mitigation options in other sectors. Agriculture shows similar potential to forestry, industry and energy supply and has higher potential than the transport and waste sectors. A large proportion of the economic mitigation potential (at 100 US$/t CO2-eq. and excluding bio-energy) arises from soil carbon sequestration, which has strong synergies with sustainable agriculture and generally reduces vulnerability to climate change. Significant potential is also available from reductions in methane and nitrous oxide emissions, and such emissio