The climate of the future will increasingly be characterized by so-called flash droughts: a phenomenon of shorter duration, which appears with little warning and develops very quickly, and thus can be very dangerous. The study indicates this published In Science Journal and led by China’s Nanjing University of Information Science and Technology.

Droughts are caused by man-made climate change and see Europe among the hardest hit regions, with eastern and northern Asia, southern Australia, the Sahara and the western coast of South America.

The data underscores the urgent need to find solutions, such as early warning systems, to mitigate the impact of these phenomena and manage their risks, also because researchers expect that the affected areas will expand further. Droughts are mainly caused by internal climatic fluctuations that occur on seasonal or annual time scales. However, recent studies have shown that droughts can also occur over much shorter time scales and turn into severe episodes within a few weeks.

These “rapid droughts,” which didn’t get much attention until a summer 2012 event that affected more than half of the United States, are hard to predict, so their effects can be particularly severe. Researchers led by Xing Yuan evaluated changes in the incidence of droughts over the past 64 years on a global scale. The results show a transition to a greater number of sudden droughts in most parts of the world, associated with increased evaporation of water into soils and decreased precipitation: both phenomena are attributed to human-induced climate change.

In particular, for wetter regions such as Europe, northern Asia, southern China, parts of eastern and north-central North America, and the Amazon, sudden droughts result primarily from accelerated soil moisture loss. However, in the drier regions, which include northern China, western India and many regions of Africa, the evaporation of water contained in the soil is limited, and thus the main driver of the drought phenomenon lies in the lack of rain. In addition, the transition to rapidly increasing aridity is expected to expand to most land areas in the future, especially if greenhouse gas emissions are not significantly reduced, according to the study authors. As the researchers point out, it is necessary to find ways to adapt to these phenomena, which will soon become the new normal.