Indian methane and nitrous oxide emissions and mitigation flexibility

Abstract

Methane (CH4) and nitrous oxide (N2O) contributed 27% and 7%, respectively, to India's CO2 equivalent greenhouse gas (GHG) emissions in 2000, the remaining being the carbon dioxide (CO2) emissions. Presently, agriculture and livestock related emissions contribute above 65% of Indian CH4 emissions and above 90% of N2O emissions. Since these activities are widely dispersed, with a considerable portion being sub-sustenance activities, emission mitigation requires considerable efforts. We use geographical information system (GIS) interfaced Asia-Pacific Integrated Model (AIM/Enduse), which employs technology share projections, for estimating future CH4 and N2O emissions. The future emissions and mitigation flexibility are analyzed for a reference scenario and two mitigation scenarios (medium and strong). Future CH4 emissions in 2030 are projected to reach 24.4 Tg (reference scenario), 21.3 Tg (medium mitigation scenario) and 17.6 Tg (strong mitigation scenario). Future CH4 emission scenarios indicate rising shares of municipal solid waste (MSW) and coal bed methane, where mitigation technologies have good penetration potential. Improved cattle feed and digesters, and better rice paddy cultivation practices that are adopted for higher yields and improved irrigation coverage also offer CH4 mitigation as ancillary benefits. Future N2O emissions in 2030 are projected to reach 0.81 Tg (reference scenario), 0.69 Tg (medium mitigation scenario) and 0.6 Tg (strong mitigation scenario). Better utilization of nitrogen fertilizer and increased use of organic fertilizers, partly produced from MSW, offer interesting mitigation opportunities for N2O emissions. Some of these technology initiatives are already visible in India at different stages of development and appropriate policy thrust may strengthen them in future.