Author(s): Parisa Hosseinzadehtalaei; Piet Termonia; Hossein Tabari
Linked Author(s): Hossein Tabari, Parisa Hosseinzadehtalaei
Keywords: Compound hot-dry events Climate change Uncertainty analysis
Abstract: Compound hot-dry events (CDHEs) are projected to intensify with global warming, posing significant risks to water resources and ecosystems. These events exacerbate water scarcity by increasing demand across various sectors. However, uncertainties in CDHE projections hinder the development of effective adaptation and mitigation strategies. This study evaluates the sources of uncertainty in global-scale CDHE projections by analyzing outputs from 22 CMIP6 GCMs under four Shared Socioeconomic Pathways (SSPs). Using four hydrological variable-based definitions, we quantify CDHEs globally by the end of the 21st century. Results indicate that GCM uncertainty is the primary contributor in 17 out of 20 IPCC regions. Across all regions, scenario uncertainty accounts for an average of 33%, while uncertainties related to the definitions of compound events contribute 19%. Our findings reveal that while GCMs are the dominant source of uncertainty in projections of compound hot-dry events, the often-overlooked uncertainty from extreme event definitions also demands greater attention.
Year: 2025