资源环境科技发展态势分析平台

Anthropogenic forcing is anticipated to increase the magnitude and frequency of extreme events(1), the impacts of which will be particularly hard-felt in already vulnerable locations such as Africa(2). However, projected changes in African climate extremes remain little explored, particularly in the context of the Paris Agreement targets(3,4). Here, using Community Earth System Model low warming simulations(5), we examine how heat and hydrological extremes may change in Africa under stabilized 1.5 degrees C and 2 degrees C scenarios, focusing on the projected changing likelihood of events that have comparable magnitudes to observed record-breaking seasons. In the Community Earth System Model, limiting end-of-century warming to 1.5 degrees C is suggested to robustly reduce the frequency of heat extremes compared to 2 degrees C. In particular, the probability of events similar to the December-February 1991/1992 southern African and 2009/2010 North African heat waves is estimated to be reduced by 25+/-5% and 20+/-4%, respectively, if warming is limited to 1.5 degrees C instead of 2 degrees C. For hydrometeorological extremes (that is, drought and heavy precipitation), by contrast, signal differences are indistinguishable from the variation between ensemble members. Thus, according to this model, continued efforts to limit warming to 1.5 degrees C offer considerable benefits in terms of minimizing heat extremes and their associated socio-economic impacts across Africa.