Rapid Methane Action, Tipping Points in the Climate System, and Economic Climate Damages
AbstractThe climate impacts of methane emissions have increasingly attracted attention. Methane mitigation is seen as both rapid and cost-effective: cutting methane would lower the rate of warming and therefore climate damages in the near term. It hence would provide complementary benefits to the longer-term ones achieved by decarbonization on the way to net-zero. However, to date, no research has quantified how much the avoided near-term warming from rapid methane action would reduce the economic damages from climate change. Moreover, more limited temperature overshoot on a pathway towards a Paris-compatible temperature target could lower the risks from economic damages related to tipping points.
In this work, we couple a frontier climate economics toolkit with the latest methane science and recent methane action scenarios. The scenarios are based on the Global Methane Assessment (GMA), which forms the evidence base for much of the most recent policy action on methane, such as the Global Methane Pledge. Our analysis includes scenarios with taxation, the implementation of the Global Methane Pledge, 1.5C-consistent scenarios and implementation of all identified technical mitigation options from the GMA.
Our toolkit centres around the META model, a recent climate-economy integrated assessment model that combines frontier damage functions at the country-level for both temperature and sea-level rise and recent advances in climate science. META also allows us to study tipping points in the climate system, and it includes an explicit methane emissions module updated to match the latest methane science. META will be implemented using the Mimi Framework in Julia.
Estimates for economic climate impacts in each scenario will focus on marginal damages (SC-CH4, SC-CO2, and the ratio of both), total damages and damages due to tipping points in the climate system. We also produce geophysical estimates for how rapid methane action affects warming and sea-level rise around the world.