1. On the optimality of 2°C targets and a decomposition of uncertainty.
- Author
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van der Wijst, Kaj-Ivar, Hof, Andries F., and van Vuuren, Detlef P.
- Subjects
CLIMATE change mitigation ,DISCOUNT prices ,UNCERTAINTY (Information theory) ,UNCERTAINTY ,GREENHOUSE gas mitigation ,CARBON pricing - Abstract
Determining international climate mitigation response strategies is a complex task. Integrated Assessment Models support this process by analysing the interplay of the most relevant factors, including socio-economic developments, climate system uncertainty, damage estimates, mitigation costs and discount rates. Here, we develop a meta-model that disentangles the uncertainties of these factors using full literature ranges. This model allows comparing insights of the cost-minimising and cost-benefit modelling communities. Typically, mitigation scenarios focus on minimum-cost pathways achieving the Paris Agreement without accounting for damages; our analysis shows doing so could double the initial carbon price. In a full cost-benefit setting, we show that the optimal temperature target does not exceed 2.5 °C when considering medium damages and low discount rates, even with high mitigation costs. With low mitigation costs, optimal temperature change drops to 1.5 °C or less. The most important factor determining the optimal temperature is the damage function, accounting for 50% of the uncertainty. Determining attractive response strategies for international climate policy is a complex task. Here, the authors develop a meta-model that disentangles the main uncertainties using full literature ranges and use it to directly compare the insights of the cost-minimising and cost-benefit modelling communities. [ABSTRACT FROM AUTHOR]
- Published
- 2021
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