Estimates of natural methane emissions into the atmosphere in the regions of Western Siberia by model simulations

Abstract

Model estimates of changes in natural methane emissions into the atmosphere were obtained for the regions of Western Siberia, including the estimates of wetland ecosystems and decomposition of relict methane hydrates contributions to these changes in the high latitude cryolithozone. Regional model estimates of methane fluxes into the atmosphere were obtained using the results of calculations with the ensemble of global climate models CMIP6 under different scenarios of anthropogenic forcing for the 21st century. According to the model estimates, the increase in regional natural methane emissions in the 21st century under the SSP585 scenario with the most aggressive anthropogenic impacts is more than 2 times greater than under the SSP126 scenario with the least aggressive anthropogenic impacts. Dissociation of relic methane hydrates in the permafrost resulting in methane emissions into the atmosphere in the north of Western Siberia are estimated to be considerably less significant compared to the regional emissions of wetland ecosystems under current climatic changes.