In August 2022, an unprecedented compound heatwave and drought event (CHDE) lasting 24 days occurred in the Yangtze River valley (YRV), leading to a severe reduction of the crop, fresh water, and power supply. We constructed a joint cumulative probability distribution of heatwave and drought intensity, and found that the lowest probability-based index (PI) of 0.06 in 2022 was estimated as a 1-in-662-year event over the 1961–2022 climate. We then detected the fingerprint of greenhouse gas forcing to the observed PI in a generalized extreme value framework, but not the aerosol forcing, suggesting the leading contribution of greenhouse gas forcing on such extreme CHDE. Furthermore, anthropogenic influence had increased the probability of such CHDE by more than 10 times compared to the counterfactual climate. Also, the PI decreased from about 0.30 at the present climate to about 0.14 at the 3 °C global warming level, indicating that CHDE will become more extreme over YRV.

2022年8月，长江流域发生了一场史无前例的持续24天的热浪与干旱复合事件（CHDE），导致农作物、淡水和电力供应严重减少。我们构建了热浪和干旱强度的联合累积概率分布，发现 2022 年基于概率的指数 (PI) 最低为 0.06，估计为 1961-2022 年气候中 662 年一遇的事件。然后，我们在广义极值框架中检测到温室气体强迫对观测到的 PI 的指纹，但没有检测到气溶胶强迫，这表明温室气体强迫对这种极端 CHDE 的主要贡献。此外，与反事实气候相比，人为影响使此类 CHDE 发生的概率增加了 10 倍以上。此外，PI从当前气候下的约0.30下降到全球变暖3°C水平下的约0.14，表明CHDE在长江流域将变得更加极端。