The South Asian summer monsoon is one of the most important climate phenomena for summer in the Northern Hemisphere, influencing extreme weather and climate events particularly over Asia and impacting over one billion people’s lives. Decisions on climate change adaptation and policy for this heavily populated region will depend on future potential changes to the monsoon. To help inform decision making, a new study from an international group of Chinese and American researchers, funded in part by CPO’s Climate Variability and Predictability (CVP) program, quantifies how a change in global mean surface temperature will affect the South Asian summer monsoon, providing new insight into global warming’s impact. The study is available as an early online release in the Journal of Climate.
The research team analyzed the monsoon’s circulation and precipitation characteristics using climate model simulations under a warming climate from 1.5° to 5°C. They found that the resultant changes to both circulation and precipitation could be described roughly linearly in relation to temperature itself. This means that for every degree increase in temperature, the monsoon’s circulation weakens by a set amount and precipitation increases by a set amount. The authors note that since these results are based only on one large-ensemble model, the relationship needs to be examined further with more climate models.