Larger Contribution of Anthropogenic Climate Change to the Increasing Frequency of Compound Droughts and Heatwaves in Poor Countries Compared to Wealthy Ones

Abstract

Abstract Compound drought-heatwave events (CDHWs) have attracted widespread attention due to their devastating effects on human societies and ecosystems, but little research has investigated inequalities in exposure to CDHWs under climate change. Here, we reveal a significant connection between CDHWs and poverty on a global scale using observations, global climate models, and climate change attribution. We find that low-income regions, located mainly in central Africa, experienced an increase of 377% [351%~403%] in the frequency of CDHWs from 1981 to 2020, twice as fast as high-income regions in other parts of the globe (184% [153%~204%]). In the absence of climate change, the frequency of CDHWs would not have increased in low-income regions but would still have increased in high-income regions. Climate change has doubled the frequency of CDHWs over 31% [14%~50%] of low-income regions, yet only over 4.7% [0.9%~8.3%] of high-income regions. We also show that anthropogenic climate change has made a greater contribution to increases in the frequency of CDHWs in poorer countries than in wealthier countries. These findings highlight the need to prioritize climate policies to mitigate social inequalities exacerbated by anthropogenic influences and to achieve sustainable development goals.