US and Chinese climate experts share judgements on solar geoengineering

Expert judgements on solar geoengineering (SG) inform policy decisions and influence public opinions. We performed face-to-face interviews using formal expert elicitation methods with 13 US and 13 Chinese climate experts randomly selected from IPCC authors or with snowball sampling. We compare their judgments on climate change, SG research, governance, and deployment. We found few significant differences between quantitative judgments of US and Chinese experts. US and Chinese experts differed on topics such as desired climate scenario and the preferred venue for international regulation of SG, providing some insight into divergent judgments that might shape future negotiations about SG policy. We also gathered closed-form survey results from 19 top academic SG experts. Both expert groups supported greatly increased research, recommending SG research funding of 5.4% (10^th to 90^th percentile range was 1-10%) of climate science budgets compared to actual budgets of <0.3% in 2018. Climate experts chose far less SG deployment in future climate policies than did SG experts.