Future changes of drought characteristics in Coupled Model Intercomparison Project phase 6 Shared Socioeconomic Pathway scenarios over Central Asia

Understanding of future changes in drought characteristics is crucial for climate change adaptation and drought impact mitigation. We analysed the projected changes in drought characteristics relative to historical drought conditions in Central Asia using the Standardized Precipitation Evapotranspiration Index based on both gridded observations and an ensemble of bias-corrected and spatially disaggregated global circulation models (GCMs) from phase 6 of Coupled Model Intercomparison Project (CMIP6). The results suggest that precipitation and potential evapotranspiration are projected to increase across Central Asia. Even though the change in wetness may not be significant and robust, a dry gets drier and wet gets wetter pattern may emerge in future under different scenarios. Drought events in Central Asia's semi-arid and arid regions (aridity index <0.5) are projected to become more frequent (>125%), with longer duration (>55%), higher severity (>74%) and intensity (>8%) by the end of the 21st century under four Shared Socioeconomic Pathway (SSP) scenarios. In the coming period of 2021-2050, Central Asia is expected to have more drought events with a longer duration but lower intensity. Comparisons between different SSP scenarios stress the importance of climate change mitigation strategies to avoid more drought occurrence, longer drought duration and higher drought severity. The long-term mitigation and adaptation studies for increasing drought impacts are also imperative in Central Asia.

Automated summary

Projected increases in precipitation and potential evapotranspiration across Central Asia suggest a future trend of more frequent, longer, and more severe drought events in semiarid and arid regions. Comparisons between different scenarios highlight the importance of climate change mitigation strategies in avoiding worsening drought occurrences.