Future atmospheric methane concentrations in the context of the stabilization of greenhouse gas concentrations

摘要

Tropospheric CH_4 concentration depends, according to modeled tropospheric processes, on many factors, including emissions of CH_4 as well as NO_x and CO. Illustrative analyses of the relation between emissions and CH_4 concentration give some guidance on the role of CH_4 in the stabilization of greenhouse gas concentrations. The contribution of CH_4 to radiative forcing at the time of stabilization is expected to be modest, provided CH_4 and CO emissions do not go far beyond current rates. However, in cases leading to stabilization the potential mitigation of increases in radiative forcing by methane control could be comparable to that of CO_2 control over the next century. Whether or not this potential is realized will depend partially on the cost of deep reductions of CH_4, NO_x, CO, or CO_2 emissions over the next century, which is not known.