Atmospheric temperature response to ambitious climate mitigation scenarios from RESCUE

Limiting global warming in line with the objectives of the Paris Agreement requires rapid global emission reductions. Considering current policy, it is very likely that these reductions will not be enough and that the implementation of Carbon Dioxide Removal (CDR) measures is needed in addition. Within the RESCUE project ambitious climate mitigation scenarios were designed with the same end-of-century carbon emission budgets (1150 Gt CO2 and 500 Gt CO2) with and without overshoot. This allows us to investigate potential Earth system responses to the application of different activity-driven CDR portfolios using emissions-driven Earth System Model (ESM) simulations. The CDR measures implemented in these scenarios include bioenergy with carbon capture and storage, direct air capture and storage, afforestation and reforestation, and ocean alkalinity enhancement.

Here, we present initial results from using the RESCUE scenarios in our FOCI climate model, which is one of five ESMs involved in the RESCUE project. Based on our FOCI simulations, we investigate the differences of atmospheric temperature in the overshoot and stabilization pathways to evaluate how fast climate mitigation measures are detectable in the global climate system. Acknowledging detection challenges in global ESM experiments in the context of ambitious mitigation pathways, we extend our analysis to include stratospheric temperature responses, expecting a more distinct signal-to-noise ratio compared to the troposphere.