Delaying methane mitigation increases the risk of breaching the 2 °C warming limit

• Published in: Communications earth & environment Vol. 4; no. 1; pp. 250 - 8
• Main Authors: Nzotungicimpaye, Claude-Michel, MacIsaac, Alexander J., Zickfeld, Kirsten
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group 01.12.2023; Nature Portfolio
• Subjects: Carbon cycle; Carbon dioxide; Carbon dioxide emissions; Climate change; Climate models; Emissions; Global warming; Methane; Mitigation
• ISSN: 2662-4435; 2662-4435
• DOI: 10.1038/s43247-023-00898-z

Abstract Atmospheric methane levels are growing rapidly, raising concerns that sustained methane growth could constitute a challenge for limiting global warming to 2 °C above pre-industrial levels, even under stringent CO 2 mitigation. Here we use an Earth system model to investigate the importance of immediate versus delayed methane mitigation to comply with the 2 °C limit under a future scenario of low CO 2 emissions. Our results suggest that methane mitigation initiated before 2030, alongside stringent CO 2 mitigation, could enable to limit global warming to well below 2 °C over the next three centuries. However, delaying methane mitigation to 2040 or beyond increases the risk of breaching the 2 °C limit, with every 10-year delay resulting in an additional peak warming of ~0.1 °C. The peak warming is amplified by the carbon-climate feedback whose strength increases with delayed methane mitigation. We conclude that urgent methane mitigation is needed to increase the likelihood of achieving the 2 °C goal.