The impact of climate change on droughts in Central Asia assessed using regional climate models

Climate change is expected to aggravate the frequency and intensity of extreme weather events such as droughts but impacts are found to strongly vary per region. For different reasons the region of Central Asia has been sparsely studied in that respect. To enable well-informed decision making for adaptation and mitigation, however, regional authorities in Central Asia are interested in a comprehensive and scientifically-based assessment. This work will provide an assessment of the impact of climate change on droughts that affect the agriculture and forestry in Central Asia, based on recently produced climate projections of regional climate models. The aim is to quantify and project changes in extreme events via different climate parameters and to investigate which factors modify the signal of change. This work therefore focuses on multiple drought indices and methodologies, and includes results from four regional climate models. After model validation, the changes in future droughts and associated characteristics are estimated over IPCC sub-regions under multiple global warming scenarios. The results show an overall increase in both precipitation and evaporation for the future. Changes in drought are therefore determined by the local balance of rainfall and evaporation changes, and major seasonal and regional differences are found. Croplands and grasslands, appearing at mid-latitudes will experience the highest increase in drought characteristics. Forest vegetation occurring in northern regions (Russia), on the other hand, is projected to experience little change or even a decrease in drought risks.