The role of an interactive methane cycle in the Earth System

Despite methane’s importance as a greenhouse gas, the Earth System Models that contributed to Phase 6 of the Coupled Model Intercomparison Project (CMIP6) typically prescribe surface methane concentrations - following either historical observations or specified future shared socioeconomic pathways. Here, we make use of a methane emissions-driven configuration of the UK’s Earth System Model to explore the role of an interactive methane cycle, including a wetlands emissions scheme, on the model’s equilibrium climate sensitivity and its transient climate response to changes in carbon dioxide concentration. In addition, climate-driven feedbacks play a fundamental role in determining the climate response to external forcings and this work will investigate the impact of interactive methane on the assessment of relevant Earth System feedbacks.

This presentation will demonstrate the need for including interactive methane in Earth System Models, thereby enabling decision makers to determine the consequences of methane emission reduction policies or climate feedbacks on natural methane sources towards meeting global climate as well as global air quality targets.