Global Changes in Drought Conditions Under Different Levels of Warming

This publication from Nauman et al. (2018) presents results of research investigating the climatology of global drought conditions under different global warming levels. Warming levels of 1.5 and 2°C set out as mitigation targets in the Paris Agreement, as well as 3°C where considered in their research and it was found that the magnitude of droughts could to double in 30% of the global landmass under stringent mitigation policies.

According to the authors current 1-in-100-year droughts would occur every two to five years for most of Africa, Australia, southern Europe, southern and central United States, Central America, the Caribbean, north-west China, and parts of Southern America. Approximately two thirds of the global population will experience a progressive increase in drought hazard with warming. In drying areas, drought durations are projected to rise rapidly.

The lowering of the groundwater and of the water levels in reservoirs are described as main impacts which will impede replenishment of water supplies and may result in a difficult recovery and prolonged socio-economic impacts after severe droughts. This could pose considerable challenges for the design of water resource systems in many regions of the world to cope with more frequent periods of reduced water availability.