Future Global Meteorological Drought Hot Spots: A Study Based on CORDEX Data

Abstract

Two questions motivated this study: 1) Will meteorological droughts become more frequent and severe during the twenty-first century? 2) Given the projected global temperature rise, to what extent does the inclusion of temperature (in addition to precipitation) in drought indicators play a role in future meteorological droughts? To answer, we analyzed the changes in drought frequency, severity, and historically undocumented extreme droughts over 1981–2100, using the standardized precipitation index (SPI; including precipitation only) and standardized precipitation-evapotranspiration index (SPEI; indirectly including temperature), and under two representative concentration pathways (RCP4.5 and RCP8.5). As input data, we employed 103 high-resolution (0.44°) simulations from the Coordinated Regional Climate Downscaling Experiment (CORDEX), based on a combination of 16 global circulation models (GCMs) and 20 regional circulation models (RCMs). This is the first study on global drought projections including RCMs based on such a large ensemble of RCMs. Based on precipitation only, ~15% of the global land is likely to experience more frequent and severe droughts during 2071–2100 versus 1981–2010 for both scenarios. This increase is larger (~47% under RCP4.5, ~49% under RCP8.5) when precipitation and temperature are used. Both SPI and SPEI project more frequent and severe droughts, especially under RCP8.5, over southern South America, the Mediterranean region, southern Africa, southeastern China, Japan, and southern Australia. A decrease in drought is projected for high latitudes in Northern Hemisphere and Southeast Asia. If temperature is included, drought characteristics are projected to increase over North America, Amazonia, central Europe and Asia, the Horn of Africa, India, and central Australia; if only precipitation is considered, they are found to decrease over those areas.

Climate change impact on flood and extreme precipitation increases with water availability

“…PET is computed by the Hargreaves-Samani method 58 which effectively incorporates solar radiation by its indirect estimation from minimum and maximum temperatures. The use of both minimum and maximum temperature avoids the PET overestimation in dry and hot climates by methods based on only mean temperature such as the Thornthwaite method 28,59,60 www.nature.com/scientificreports/ investigate the possible impact of climate change on climate regimes (aridity classifications), the change in the area of each class (% of total terrestrial land area) is calculated. Once the spatial distribution of the global climate regimes is acquired, the median change of extreme precipitation and flood intensity for each climate regime is determined.…”

A multi-model, multi-scenario, and multi-domain analysis of regional climate projections for the Mediterranean

“…The GCM/ RCM matrix for these two domains is almost identical (Table S1). Such merging of information derived from different CORDEX domains' simulations has been previously applied on a global scale study (Spinoni et al 2019).…”

Hydroclimate changes over Sweden in the twentieth and twenty-first centuries: a millennium perspective

“…Annual precipitation is projected to increase during near-term (∼2011-2040), midterm (∼2041-2070), and long-term (∼2071-2100) under RCP4.5, RCP8.5, A1B, A2, and B3 with reference to (w.r.t.) a 30-year historical period during 1961-2010 (Räisänen et al 2003;Dai 2011a;Eklund et al 2015;Sjökvist et al 2015;Zhao and Dai 2017;Dezsi et al 2018;Spinoni et al 2020). In addition to the projected increase in annual precipitation over Sweden under RCPs and SRES, the precipitation is also projected to increase following the increase in the CO 2 , based on CMIP5 transient CO 2 increase to 2 × CO 2 simulations (Fu and Feng 2014).…”