a, Implementation of CP_Price scenarios. First, current policies are explicitly implemented to 2030, and the resulting emissions in 2030 are recorded. Second, models are re-run to reach the same levels of emissions as in the previous step using a carbon price (C 1 ) alone. Third, scenarios are extended post-2030 by growing the carbon price (C 1 ) with GDP per capita. The resulting emissions pathways (P 1 (t)) are recorded. Fourth, models are re-run with current policies explicitly implemented to 2030, and as constant or minimum bounds on effort post-2030. The emissions pathways achieved in the previous step (P 1 (t)) are implemented as upper bounds on emissions. b, Implementation of NDC_Price scenarios follows the implementation of CP_Price scenarios, except for the first step. First, current policies are explicitly implemented to 2030. Then, the emissions levels achieved in 2030 in each model region are compared with NDC targets. When additional effort is required to achieve NDC targets, this is implemented on top of current policies. See Supplementary Text 2 for the full scenario protocol.
https://www.nature.com/articles/s41558-021-01206-3
A multi-model analysis of long-term emissions and warming implications of current mitigation efforts
