Exeter University
Mathematics

At the recent COP26, over 100 countries, including the US, UK and EU, signed up for the Global Methane Pledge: a pledge to reduce emissions of methane by 30% within the next decade. This growing political interest in regulating methane emissions is because it is viewed as the easiest, cheapest and most feasible way to slow climate change in the near-future. However, the current evidence base for the regional and global climate benefits of methane mitigation is extremely limited and based on highly-idealised emulators. Hence, there is a pressing need for targeted methane reduction experiments with state-of-the-art comprehensive climate models. To bridge this gap, I will lead an internationally-coordinated model intercomparison project, MethaneMIP, to robustly quantify the climate benefits attributable to different methane mitigation strategies. This research will examine near-term climate change under four scenarios (no mitigation, economically- profitable mitigation, aggressive mitigation, and aggressive mitigation coupled with behavioural change). To ensure that the results are not dependent on an individual climate model, the identical set of experiments will be conducted using six different CMIP6-standard comprehensive climate models from modelling centres across the world. This proposed work will advance the state-of-the-art knowledge by allowing us to answer questions such as: Which methane mitigation strategies are consistent with the 1.5C and 2C targets agreed to under the Paris Climate Accord possible? What are the regional climate benefits of the different mitigation strategies in terms of temperature and precipitation extremes, wildfire risk, and public health? Can mitigation strategies delay impending features of climate change such as the occurrence of the first ice-free Arctic summer? When will the climate benefits of mitigation emerge from the climate noise of internal variability? This work will have important societal benefits in informing climate policy in a time of tremendous political interest in methane mitigation, and could help push governments to stick to their 2030 reduction pledges and spur new countries, such as Russia and China, to adopt these measures. The results of this work will be communicated to policymakers via relevant reports from such as the IPCC report, the UNEP Methane report, and the UNEP Emissions Gap report.