Clim. Dynam. http://doi.org/dzkt (2020).

Regional monsoons, including the South Asian and West African systems, are characterized by a highly uneven precipitation distribution throughout the year. The majority of the global population resides in areas impacted by these systems, and understanding the effect of climate warming on their intensity, onset and withdrawal is important in estimating future impacts. Global climate models exhibit uncertainty at the scales needed to capture monsoon dynamics, leading to spread in future monsoon behaviour and the need for more regionalized studies.

Moetasim Ashfaq of Oak Ridge National Laboratory, Tennessee, USA, and co-authors analysed regional climate model experiments covering nine distinct monsoons, focusing on their response to low- and high-end warming scenarios. Under high warming, all monsoons experience a contracted wet season by 2100, with heavier precipitation during the season’s peak but less before and after. The onset and withdrawal dates also shifted later. In contrast, the low-end warming did not significantly alter future monsoons, highlighting the potential for strong emissions controls to mitigate changes to these high-impact phenomena.