Climate extremes such as heatwaves and droughts pose increasing threats to human safety, economies, and ecosystems in a warming climate. However, scientists still poorly understand their key drivers and future changes.

In Turpan’s Flaming Mountains, Xinjiang, the temperature exceeds 50°C, and the ground is hot enough to cook eggs directly. (Image by QIN Peihua)

Recently, researchers from the Institute of Atmospheric Physics at the Chinese Academy of Sciences revealed the spatiotemporal evolution of heatwaves globally and in China, identified the dominant driving factors, and assessed the associated compound risks.

Using a gridded daily maximum and minimum temperature dataset from the China Meteorological Administration, the team found that the frequency of both daytime and nighttime heatwaves increased significantly across most areas of China from 1961 to 2022. Furthermore, surface air temperature was identified as the dominant drivers of the increase in heatwaves in China using redundancy analysis and hierarchical partitioning methods.

Because compound heatwave and drought events exert more severe impacts than individual extremes, further analysis revealed that surface air temperature has a stronger impact on compound extremes than on heatwaves alone. Moreover, population growth, together with intensifying compound extremes, led to moderate increases in exposure during 1991–2020.

At 1.5°C and 2.0°C global warming levels, multiple climate models from the sixth phase of the Coupled Model Intercomparison Project (CMIP6) project that the frequency and intensity of heatwaves will increase globally under the intermediate (SSP245) and very high (SSP585) emission scenarios. The Shapley additive explanation method shows that regional surface air temperature dominantly contributes to heatwave changes under the SSP245 scenario, while global sea surface temperature plays a more important role under the SSP585 scenario.

“Our results show that heatwaves and compound heatwave–drought events will occur more frequently under a warming climate, which might lead to more severe climate risks,” said Dr. QIN Peihua, the lead author of a series of studies published in Quarterly Journal of the Royal Meteorological Society, Atmospheric Research, and Climate Dynamics..

The studies therefore also calls for targeted risk mitigation and adaptation strategies based on regional population exposure characteristics.

Paper info:

1. Qin, P. H.^*, Z. H. Xie, and B. H. Jia (2025) Relative importance of driving factors for daytime and nighttime heatwaves in China. Quarterly Journal of the Royal Meteorological Society, 151, e5045. https://doi.org/10.1002/qj.5045.

2. Qin, P. H.^*, Z. H. Xie, and B. H. Jia (2026) Increasing exposure to compound heatwave and drought events in China during 1961–2020. Atmospheric Research, 340, 109099. https://doi.org/10.1016/j.atmosres.2026.109099.

3. Qin, P. H.^*, and Z. H. Xie (2026) Intensifying heatwaves under 1.5 or 2.0 °C warming climate by increasing regional surface air temperature and global SST. Climate Dynamics, 64, 246. https://doi.org/10.1007/s00382-026-08223-y.