Increasing cloud water resource in a warming world

Under global warming, terrestrial water resources regulated by precipitation may become more unevenly distributed across space, and some regions are likely to be highly water-stressed. From the perspective of the hydrological cycle, we propose a method to quantify the water resources with potential precipitation capacity in the atmosphere, or hydrometeors that remain suspended in the atmosphere without contributing to precipitation, namely cloud water resource (CWR). During 2000–2017, CWR mainly concentrates in the middle-high latitudes which is the cold zone of the Köppen classification. In a warming world, CWR shows a significant increase, especially in the cold zone. Climate change with Arctic amplification and enhanced meridional circulation both contribute to the change of CWR through influencing hydrometeor inflow. By studying the characteristics of CWR and its influencing mechanisms, we demonstrate a potential for human intervention to take advantage of CWR in the atmosphere to alleviate terrestrial water resource shortages in the future.