Estimates of changes in the rate of methane sink from the atmosphere under climate warming

The temperature dependence of the methane oxidation rate is estimated. The methane lifetime in the atmosphere is shown to decrease by about 3% from 1900 to 2005. The overwhelming fraction of the total methane content is removed from the atmosphere at intratropical latitudes during the daytime. The methane oxidation rate growth due to the temperature increase in the troposphere generates negative feedback in the methane cycle and, accordingly, climatic feedback with the same sign. According to the estimates performed, the halt in methane concentration growth in the atmosphere observed in recent years can be associated with a decrease in the lifetime of methane in the atmosphere. According to the results of numerical experiments with the climatic model of the Institute of Atmospheric Physics, Russian Academy of Sciences (IAP RAS), the climatic effect of negative feedback of the tropospheric temperature and the methane lifetime in the atmosphere is not large and is comparable with the climatic forcing of the methane emission growth from bog ecosystems.