Recent changes in global dryland temperature and precipitation

Abstract Changes in dryland temperature and precipitation are essential components of dryland climate change. This study applies the use of the monthly reanalysis data product of ERA5, which has a spatial resolution of 0.25°, to investigate the changes in the dryland climate between 1979 and 2018. The result revealed warming and drying of the drylands in recent decades, most notably in the current decade. The general global dryland temperature and precipitation increased and decreased significantly (0.01 significance level) at the rate of 0.032°C·year −1 and 0.074 mm·month −1 ·year −1 , respectively, in the last 40 years. Although precipitation generally decreased over the drylands, summer precipitation increased over southern Africa and Australia as well as northern Africa and south Asia dryland areas. Variation in the warming rate over the dryland zones at different periods was also observed. The semiarid and dry subhumid warmed continually from the first decade (0.02°C·year −1 and 0.017°C·year −1 ) to the fourth decade (0.077°C·year −1 and 0.065°C·year −1 , respectively), while the hyperarid warmed at a slower rate in the last two decades compared to the prior decades. More intense warming was also observed in the areas where precipitation decreased, suggesting the effect of reduced evaporative cooling. These changes have implications on the dryland environment, such as aridity changes, which could affect the sustainable development of the areas through the corresponding impact on the ecosystem.