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Emergent constraints on carbon budgets as a function of global warming.

ABSTRACT: Earth System Models (ESMs) continue to diagnose a wide range of carbon budgets for each level of global warming. Here, we present emergent constraints on the carbon budget as a function of global warming, which combine the available ESM historical simulations and future projections for a range of scenarios, with observational estimates of global warming and anthropogenic CO₂ emissions to the present day. We estimate mean and likely ranges for cumulative carbon budgets for the Paris targets of 1.5 °C and 2 °C of global warming of 812 [691, 933] PgC and 1048 [881, 1216] PgC, which are more than 10% larger than the ensemble mean values from the CMIP6 models. The linearity between cumulative emissions and global warming is found to be maintained at least until 4 °C, and is consistent with an effective Transient Climate Response to Emissions (eTCRE) of 2.1 [1.8, 2.6] °C/1000PgC, from a global warming of 1.2 °C onwards.

SUBMITTER: Cox PM

PROVIDER: S-EPMC10904375 | biostudies-literature | 2024 Feb

REPOSITORIES: biostudies-literature

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Emergent constraints on carbon budgets as a function of global warming.

Cox Peter M PM Williamson Mark S MS Friedlingstein Pierre P Jones Chris D CD Raoult Nina N Rogelj Joeri J Varney Rebecca M RM

Nature communications 20240229 1

Earth System Models (ESMs) continue to diagnose a wide range of carbon budgets for each level of global warming. Here, we present emergent constraints on the carbon budget as a function of global warming, which combine the available ESM historical simulations and future projections for a range of scenarios, with observational estimates of global warming and anthropogenic CO<sub>2</sub> emissions to the present day. We estimate mean and likely ranges for cumulative carbon budgets for the Paris ta ...[more]

PMID: 38424076

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