Changes in aridity and its impact on agricultural lands in East Asia for 1.5 and 2.0 °C temperature rise scenarios

This study aimed to assess the changes in aridity in East Asia (EA) over the next 80 years for the restriction of global warming based on Paris Agreement goals. Eight General Circulation Models (GCMs) that provide simulations for 1.5 and 2.0 degrees C global warming scenarios were used for this purpose. The Penman-Monteith Equation was utilized to calculate potential evapotranspiration (PET). The land-use projections data was used to identify the agricultural lands that aridity could impact. The results showed a likely increase in rainfall and PET in EA over the next 80 years. However, the spatial variability of the relative increase in rainfall and PET would cause an aridity shift in 1.2-9.7% of the total land area. Though most of the area would experience a transition to a wetter climate, nearly 2% of the land would experience a transition to a drier climate. It would cause nearly 4.4 and 6.2 thousand km2 of agricultural land to be converted from semi-arid to arid and 31.1 and 42.2 thousand km2 of land from sub-humid to semi-arid in the early period for 1.5 and 2.0 degrees C temperature rise scenarios, respectively. This indicates nearly one and a half times more expansion of aridity on agricultural land in the early period for only a 0.5 degrees C increase in temperature. A decrease in aridity in the far future for both scenarios would cause a reduction of total arid lands and, thus, its impacts on agriculture. Overall, the study revealed a possible reduction of aridity in EA in the long run if the Paris Agreement is enforced and global warming is limited.