Quantifying economic impacts of climate change under nine future emission scenarios within CMIP6

The concept of "environmental determinism" suggests that climate conditions played a substantial role in shaping modern society. To minimize the social costs of future climate change and to promote economic development through identification of cost-effective adaptation strategies and mitigation policies, quantitative assessments are needed for obtaining a better understanding of the causal impacts of climate change on human society. In this work, we estimate the economic impacts of climate change during the 21st century under nine CMIP6 scenarios, using the PAGE-ICE integrated assessment model driven by the latest anthropogenic emission and socio-economic projections. Our results show that the largest climate change damages occur under the SSP3-7.0 scenario (involving regional rivalry and high anthropogenic emissions), followed by the SSP3-LowNTCF scenario (which considers significantly reduced NTCF emissions), and that climate change damage costs are expected to grow much faster than global GDP (reaching ~47% of global GDP in 2100). Gaps in adaptation resulting from regional inequalities would lead to higher climate change damages in poorer and warmer regions such as Africa and the Middle East. The outcomes obtained under the SSP1-1.9 and SSP1-2.6 scenarios, in which the warming limit targets of 1.5 °C and 2 °C set forth in the Paris Agreement are considered, respectively, reveal that aggressive mitigation strategies pass a cost-benefit analysis and could significantly reduce the economic impacts of climate change.