Impact of interannual and multidecadal trends on methane-climate feedbacks and sensitivity.

ABSTRACT: We estimate the causal contributions of spatiotemporal changes in temperature (T) and precipitation (Pr) to changes in Earth's atmospheric methane concentration (C_CH4) and its isotope ratio δ¹³CH₄ over the last four decades. We identify oscillations between positive and negative feedbacks, showing that both contribute to increasing C_CH4. Interannually, increased emissions via positive feedbacks (e.g. wetland emissions and wildfires) with higher land surface air temperature (LSAT) are often followed by increasing C_CH4 due to weakened methane sink via atmospheric ^•OH, via negative feedbacks with lowered sea surface temperatures (SST), especially in the tropics. Over decadal time scales, we find alternating rate-limiting factor

SUBMITTER: Cheng CH 

PROVIDER: S-EPMC9226131 | biostudies-literature | 2022 Jun

REPOSITORIES: biostudies-literature