Effect of Methane Mitigation on Global Temperature under a Permafrost Feedback ...

• Main Authors: Back, Hannah, May, Riley, Naidu, Divya Sree, Eikenberry, Steffen
• Format: Report
• Language: unknown
• Published: arXiv 2023
• Subjects: Atmospheric and Oceanic Physics physics.ao-ph; Dynamical Systems math.DS; FOS Physical sciences; FOS Mathematics; permafrost
• Online Access: https://dx.doi.org/10.48550/arxiv.2304.07620; https://arxiv.org/abs/2304.07620

Earth systems may fall into an undesirable system state if 1.5 degrees celsius (C) of warming is exceeded. Carbon release from substantial permafrost stocks vulnerable to near-term warming represents a positive climate feedback that may increase the risk of 1.5 C warming or greater. Methane (CH4) is a short-lived but powerful greenhouse gas with a global warming potential 28.5 times that of carbon dioxide (CO2) over a 100 year time span. Because permafrost thaw in the coming centuries is partly determined by the warming in the 21st century, rapid reductions in methane emissions early in the 21st century could have far reaching effects. We use a reduced complexity carbon cycle model and a permafrost feedback module to explore the possibility that accelerating reductions in methane emissions could help avoid long-term warming by limiting permafrost melt. We simulate 3 extended Representative Concentration Pathway (RCP) emission scenarios (RCP 2.6, 4.5, and 6) through the year 2300 and impose methane mitigation ...