This study investigates the changes in the frequency of hydrological drought under high and low greenhouse gas concentration scenarios using multimodel hydrological simulations. It estimates the time of the first emergence of unprecedented regional drought conditions, focusing on the low-flow season. Three regions (Southwestern South America, Mediterranean Europe, and Northern Africa) show particularly robust results under the high-emission scenario, with a high likelihood of unprecedented conditions within the next 30 years regardless of emission scenario. Lower emissions significantly reduce this likelihood, and the Paris Agreement goals are shown to be effective in reducing it to an unlikely level in most regions. Adaptation measures are deemed essential.

Yusuke Satoh, Kei Yoshimura, Yadu Pokhrel, Hyungjun Kim, Hideo Shiogama, Tokuta Yokohata, Naota Hanasaki, Yoshihide Wada, Peter Burek, Edward Byers, Hannes Müller Schmied, Dieter Gerten, Sebastian Ostberg, Simon Newland Gosling, Julien Eric Stanslas Boulange, Taikan Oki