Ye et al. (2026) Anthropogenic climate change amplifies autumn heatwave risks for children during school reopening

Identification

• Journal: Weather and Climate Extremes
• Year: 2026
• Date: 2026-03-21
• Authors: Yangbo Ye, Cheng Qian, Aiguo Dai, Sihan Li, Tiantian Li, Xiuqing Cui, John S. Ji, Xiaoye Zhang
• DOI: 10.1016/j.wace.2026.100892

Research Groups

• State Key Laboratory of Earth System Numerical Modeling and Application, Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing, China
• University of Chinese Academy of Science, Beijing, China
• Department of Atmospheric and Environmental Sciences, University at Albany, State University of New York, Albany, NY, USA
• Department of Geography, University of Sheffield, Sheffield, UK
• National Key Laboratory of Intelligent Tracking and Forecasting for Infectious Diseases, Beijing, China
• China CDC Key Laboratory of Environment and Population Health, National Institute of Environmental Health, Chinese Center for Disease Control and Prevention, Beijing, China
• China Meteorological Administration Key Laboratory of Meteorological Medicine and Health, National Institute of Environmental Health, Chinese Center for Disease Control and Prevention, Beijing, China
• Vanke School of Public Health, Tsinghua University, Beijing, China
• State Key Laboratory of Severe Weather, Chinese Academy of Meteorological Sciences, Beijing, China

Short Summary

This study attributes and projects the risk of autumn heatwaves for children during school reopening in China, revealing that anthropogenic climate change has significantly amplified the frequency and intensity of such heatwaves, increasing children's exposure risk by approximately 55% under the 2024 climate. Projections indicate continued increases in heatwave intensity, which will eventually outweigh declining child populations, leading to rising exposure risks by the end of the century under high emission scenarios.

Objective

• To quantify the human influence on children's exposure risk to autumn heatwaves during school reopening periods in China, using the exceptional 2024 heatwave as a case study.
• To project future changes in the frequency, intensity, and children's exposure risk of such heatwaves under different emission scenarios to inform adaptation policies.

Study Configuration

• Spatial Scale: Primarily the Yangtze River Basin, China, with implications for other Northern Hemisphere regions.
• Temporal Scale:
  • Historical analysis: 1959–2024 (ERA5), 1850–2014 (CMIP6 historical), 1850–2020 (CMIP6 hist-nat).
  • Event focus: 1–10 September 2024 (specific heatwave).
  • Future projections: 2015–2100 (CMIP6 SSPs), specifically 2035, 2050, and 2090 climate states.

Methodology and Data

• Models used: Coupled Model Intercomparison Project Phase 6 (CMIP6) multi-model ensemble simulations (6 models).
• Data sources:
  • ERA5 reanalysis data (European Centre for Medium-Range Weather Forecasts - ECMWF) for atmospheric variables (geopotential height at 500 hPa, mean sea level pressure, volumetric soil water of the top layer, 2-meter air temperature).
  • CMIP6 historical, hist-nat, and Shared Socioeconomic Pathway (SSP1-2.6, SSP2-4.5, SSP5-8.5) simulations.
  • Global Mean Surface Temperature (GMST) anomaly data.
  • World Population Prospects (2024) and national/provincial population projection databases for children's population data.
• Methods:
  • Refined storyline-probability combined framework for attribution and projection.
  • Constructed flow analogues approach to separate contributions of atmospheric circulation, soil moisture, and thermodynamic effects.
  • Ensemble Empirical Mode Decomposition (EEMD) for nonlinear trend removal.
  • Generalized Extreme Value (GEV) shift-fit method and coupled model approach for probability-based attribution.
  • Calculation of children's heatwave exposure risk (Exposure risk = Heatwave Intensity × Children's Population).
  • Bootstrap resampling for uncertainty quantification.

Main Results

• The 2024 autumn heatwave in China's Yangtze River Basin (1–10 September) was exceptionally severe, with an intensity of 5.02 °C above climatology and an estimated return period of 325 years under current climate conditions.
• Storyline Attribution (2024 heatwave intensity): Internal climate variability (atmospheric circulation and residual soil moisture) explained 71% of the heatwave's intensity (48% from circulation, 23% from soil moisture). The thermodynamic effect of anthropogenic climate change amplified the event by 25% (ERA5) to 30% (CMIP6).
• Probability-based Attribution (2024-like heatwaves): Anthropogenic climate change increased the frequency of 2024-like heatwaves by 514 times and their intensity by 2.1 °C under the 2024 climate state (CMIP6 simulations).
• Future Projections (2024-like heatwaves):
  • Under a high emission scenario (SSP5-8.5) by 2090, 2024-like heatwaves are projected to increase in frequency by 45.4 times and in intensity by 6.5 °C compared to the 2024 climate state.
  • Even under the Paris Agreement's 2 °C target scenario (SSP1-2.6) by 2090, frequency is projected to increase by 5.2 times and intensity by 0.9 °C.
  • Future increases are attributed to both thermodynamic effects of anthropogenic climate change and anthropogenically induced changes in atmospheric circulation patterns (increased frequency and intensity).
• Children's Exposure Risk: Anthropogenic climate change increased children's exposure risk to 2024-like heatwaves by approximately 55% under the 2024 climate and population. Under high emission scenarios, future exposure risk will initially decrease due to declining child population but will increase by the end of the century as heatwave intensity strongly rises. Under the SSP1-2.6 scenario, exposure risk is projected to continue decreasing due to population decline offsetting heatwave intensity increases.

Contributions

• First study to quantify human influences on children's exposure risk to autumn heatwaves during school reopening periods, addressing a critical and underexplored climate change impact.
• Refined the storyline-probability combined attribution framework by incorporating the quantification of residual soil moisture contribution to individual extreme event intensity.
• Enhanced confidence in attribution results by cross-validating storyline and probability-based perspectives, demonstrating the dominant role of the thermodynamic effect of anthropogenic climate change.
• Provided comprehensive future projections of children's heatwave exposure risk under various emission scenarios, integrating both climate and demographic changes.
• Highlighted the urgent need for both global emission reductions and child-focused adaptation strategies to mitigate the growing risks of autumn heatwaves.

Funding

• National Natural Science Foundation of China (grant no. 42341203)
• Chinese Academy of Sciences Project for Young Scientists in Basic Research (grant no. YSBR-086)
• Jiangsu Collaborative Innovation Center for Climate Change
• National large Scientific and Technological Infrastructure “Earth System Numerical Simulation Facility”

Citation

@article{Ye2026Anthropogenic,
  author = {Ye, Yangbo and Qian, Cheng and Dai, Aiguo and Li, Sihan and Li, Tiantian and Cui, Xiuqing and Ji, John S. and Zhang, Xiaoye},
  title = {Anthropogenic climate change amplifies autumn heatwave risks for children during school reopening},
  journal = {Weather and Climate Extremes},
  year = {2026},
  doi = {10.1016/j.wace.2026.100892},
  url = {https://doi.org/10.1016/j.wace.2026.100892}
}