Solar geoengineering and carbon removal significantly lower economic climate damages

Quantifying climate change impacts informs policy decisions and risk management. However, integrated assessment models have inherent problems in simulating geoengineered climates, limiting their capacity to assess the efficacy and risks of geoengineering as complementary measures to conventional strategies. Here, we improve climate-induced economic impact assessment, without considering social and ecological damages, for 12 scenarios by assimilating projections from 48 climate models into the PAGE-ICE model. The sustainable development pathway, including considerable implicit carbon dioxide removal, cost-effectively mitigates climate change impacts, as can scenarios that combine politically pledged emissions reductions with moderate solar geoengineering (SAI-1.5). Additionally, we find that combining solar geoengineering with no mitigation (G6) or implementing delayed but stringent carbon dioxide removal (SSP5-3.4-OS) can respectively reduce end-of-century climate damages to one-half or a one-quarter of the baseline SSP5-8.5 scenario. Our findings highlight the importance, potential benefits, and trade-offs of integrating these strategies with conventional mitigation and adaptation actions.