Observational constraint on climate model projections of global compound hot-dry events and the socioeconomic risks under climate change

• Published in: Environmental research letters
• Main Authors: Yao, Lei, Leng, Guoyong, Yu, Linfei, Tu, Haiyang, Qiu, Jiali
• Format: Journal Article
• Language: English
• Published: 25.09.2024
• ISSN: 1748-9326; 1748-9326
• DOI: 10.1088/1748-9326/ad7f72

Abstract The frequency of compound hot-dry events (fHD) is projected to increase significantly with future warming, yet associated uncertainties remain considerable and poorly constrained. In this study, we constrain future projections of fHD (2070-2099) using observations of recent trends in temperature (T) and precipitation (P) (1980-2014) during the warm-seasons. The physical mechanism is that the variance of fHD across climate models is dominated by their projected changes in P (ΔP), which can be constrained by recent trends in T and P. Compared to the raw projections, the observationally constrained fHD is reduced by 9.68%~18.74%, with uncertainty narrowed by 3.79%~10.66% under the high emission scenario. The highest decline of fHD is located in regions with low population and GDP, and globally, population and GDP exposures to fHD are reduced by 6.02%~10.73% and 6.51%~12.03%, respectively. The observationally constrained fHD with lower uncertainty provides more reliable information for risk management under climate change.