Abstract
Drought risk assessment can identify high-risk areas and bridge the gap
between impacts and adaptation. However, very few dynamic drought risk
assessments and projections have been performed worldwide at high
spatial resolution (e.g., 0.5{degree sign} × 0.5{degree sign}) under
different greenhouse gas emission scenarios. Here, future global drought
risk is projected combing three components (i.e., hazard, exposure, and
vulnerability) during 2021-2100 under combined scenarios of
Representative Concentration Pathways (RCPs) and Shared Socioeconomic
Pathways (SSPs): SSP1-2.6, SSP2-4.5, SSP3-7.0, and SSP5-8.5. This study
first investigates dynamic drought risks and exposed population and GDP
across the six continents (Antarctica is not examined due to data
availability). The results show that high-risk regions mainly
concentrate in southeastern China, India, Western Europe, eastern United
States, and western and eastern Africa. Drought risk will further
strengthen in the future under four scenarios, with the highest under
SSP5-8.5 and the lowest under SSP3-7.0. Populations exposed to high
drought risk for Asia and Africa are much more than other continents.
Among four SSP-RCPs, populations exposed to high risk are the largest
under SSP3-7.0 for Africa, Asia, and South America, while under SSP5-8.5
for Australia, Europe, and North America. GDP exposed to high drought
risk is the largest for Asia among the six continents and the largest
under SSP5-8.5 among the SSP-RCPs. The most significant increases in
population and GDP under high drought risk both occur in Africa. This
study provides a scientific basis for effective adaptation measures to
enhance drought resilience in potential high-risk areas.