Opportunities and challenges in using remaining carbon budgets to guide climate policy

H. Damon Matthews , Katarzyna B. Tokarska , Zebedee R. J. Nicholls , Joeri Rogelj , Josep G. Canadell , Pierre Friedlingstein (1) , Thomas L. Frölicher , Piers M. Forster , Nathan P. Gillett , Tatiana Ilyina , Robert B. Jackson , Chris D. Jones , Charles Koven , Reto Knutti , Andrew H. Macdougall , Malte Meinshausen , Nadine Mengis , Roland Séférian (2) , Kirsten Zickfeld

1 LMD - Laboratoire de Météorologie Dynamique (UMR 8539)
2 CNRM - Centre national de recherches météorologiques

The remaining carbon budget represents the total amount of CO₂ that can still be emitted in the future while limiting global warming to a given temperature target. Remaining carbon budget estimates range widely, however, and this uncertainty can be used to either trivialize the most ambitious mitigation targets by characterizing them as impossible, or to argue that there is ample time to allow for a gradual transition to a low-carbon economy. Neither of these extremes is consistent with our best understanding of the policy implications of remaining carbon budgets. Understanding the scientific and socio-economic uncertainties affecting the size of the remaining carbon budgets, as well as the methodological choices and assumptions that underlie their calculation, is essential before applying them as a policy tool. Here we provide recommendations on how to calculate remaining carbon budgets in a traceable and transparent way, and discuss their uncertainties and implications for both international and national climate policies.

Domains: Sciences of the Universe [physics]; Earth Sciences

H. Damon Matthews, Katarzyna B. Tokarska, Zebedee R. J. Nicholls, Joeri Rogelj, Josep G. Canadell, et al.. Opportunities and challenges in using remaining carbon budgets to guide climate policy. Nature Geoscience, 2020, 13, pp.769-779. ⟨10.1038/s41561-020-00663-3⟩. ⟨insu-03668367⟩