Modeling the impact of mitigation options on methane abatement from rice fields

The enhanced concentration of methane (CH4) in the atmosphere is significantly responsible for the ominous threat of global warming. Rice (Oryza) paddies are one of the largest anthropogenic sources of atmospheric CH4. Abatement strategies for mitigating CH4 emissions from rice fields offer an avenue to reduce the global atmospheric burden of methane and hence the associated menace of climate change. Projections on population growth suggest that world rice production must increase to meet the population's food energy demand. In this scenario, those mitigation options are advocated which address both the objectives of methane mitigation and increased production of rice simultaneously. In this paper, we have formulated a nonlinear mathematical model to investigate the effectiveness and limitations of such options in reducing and stabilizing the atmospheric concentration of CH4 while increasing rice yield. In modeling process, it is assumed that implementation rate of mitigation options is proportional to the enhanced concentration of atmospheric CH4 due to rice fields. Model analysis reveals that implementation of mitigation options not always provides "win-win" outcome. Conditions under which these options reduce and stabilize CH4 emission from rice fields have been derived. These conditions are useful in devising strategies for effective abatement of CH4 emission from rice fields along with sustainable increase in rice yield. The analysis also shows that CH4 abatement highly depends on efficiencies of mitigation options to mitigate CH4 emission and improve rice production as well as on the implementation rate of mitigation options. Numerical simulation is carried out to verify theoretical findings.