Possible causes for regional zero emissions commitment signals

In scenarios with abrupt cessation of CO₂ emissions (ZECMIP) the committed warming is expected to be 0±0.3K [1]. It is imperative to understand and narrow this uncertainty range because it is similar in size to the remaining allowable warming until 1.5K. We have shown that temperature changes up to 3K are present at regional scales [2]. Furthermore significant differences between models are observed which are important to understand the uncertainties in the zero emissions committed warming.

Analysing the ZECMIP simulations of nine ESMs, we identify common climate patterns and notable differences in an idealised zero CO₂ emissions scenario. We distinguish between patterns within and outside of natural model climate variability, and will present first results for likely causes in commonalities linked to ocean circulations and predominant climate modes.

 

References:

[1] A. H. MacDougall et al., Is There Warming in the Pipeline? A Multi-Model Analysis of the Zero Emissions Commitment from CO₂, Biogeosciences 17, 2987 (2020).

[2] A. H. MacDougall, J. Mallett, D. Hohn, and N. Mengis, Substantial Regional Climate Change Expected Following Cessation of CO₂ Emissions, Environmental Research Letters 17, 114046 (2022).