Li et al. (2025) Human influence on the unprecedented 2022 extreme dragon boat water event in South China: Insights from historical and projected perspectives

Identification

• Journal: Weather and Climate Extremes
• Year: 2025
• Date: 2025-11-14
• Authors: Shenao Li, Hui Cai, Wenxuan Zhang, Wenjun Liang, Kaixi Wang, Dong Chen, Shaobo Qiao, Xian Zhu
• DOI: 10.1016/j.wace.2025.100830

Research Groups

• School of Atmospheric Sciences and Key Laboratory of Tropical Atmosphere-Ocean System Ministry of Education Sun Yat-Sen University, Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), Zhuhai, China

Short Summary

This study quantifies the influence of human-induced climate change on the unprecedented 2022 extreme dragon boat water event in South China and projects the future likelihood of similar events. It finds that anthropogenic forcing increased the event's probability by approximately 64%, with future projections indicating up to an 11-fold increase by the end of the 21st century under high-emission scenarios.

Objective

• To quantify the contribution of anthropogenic forcing factors to the 2022 extreme dragon boat water event (EDBWE) in South China.
• To determine how the probability of an event similar to the 2022 EDBWE in South China will change under different Shared Socioeconomic Pathway (SSP) scenarios in the future.

Study Configuration

• Spatial Scale: South China (defined region, see Fig. 1a in paper).
• Temporal Scale: Historical period (1961–2022 for observations, 1961–2020 for historical simulations); Future projections (2015–2100). The 2022 EDBWE occurred during May–June 2022.

Methodology and Data

• Models used: 12 coupled models from the Coupled Model Intercomparison Project Phase 6 (CMIP6), specifically experiments from the Detection and Attribution Model Intercomparison Project (DAMIP) (all-component forcing (ALL), natural-only forcing (NAT), greenhouse gas-only forcing (GHG), and aerosol-only forcing (AER)) and the Scenario Model Intercomparison Project (SIMIP) (SSP1-2.6, SSP2-4.5, and SSP5-8.5 scenarios).
• Data sources:
  • CHM_PRE daily precipitation dataset (1961–2022, 0.5° × 0.5° horizontal resolution, interpolated from 2839 sites).
  • European Centre for Medium-Range Weather Forecasts (ECMWF) Reanalysis v5 (ERA5) dataset (0.5° × 0.5° horizontal resolution, 1000 to 1 hPa isobaric coordinate system).
  • CMIP6 model simulation data (interpolated to 1.5° × 1.5° resolution).
  • Methods: Maximum 31-day cumulative precipitation (Rx31day), Percentage Precipitation Anomaly (PPA), Generalized Extreme Value (GEV) distribution, Fraction of Attributable Risk (FAR), Risk Ratio (RR), Emergence Time (ET), Mann–Kendall trend test, and a trend-preserving bias correction method (ISI-MIP approach).

Main Results

• The 2022 EDBWE was characterized by a maximum 31-day cumulative precipitation (Rx31day) anomalously 74% higher than the historical average (1961–2010), breaking previous records.
• The recurrence period of the 2022 EDBWE was estimated to be approximately 551 years based on observational data.
• Anthropogenic forcing increased the probability of an event similar to the 2022 EDBWE by approximately 64% (90% confidence interval: 35% to 90%).
• Specifically, greenhouse gas-only (GHG) forcing raised the probability by +66% (+10% to +91%), while aerosol-only (AER) forcing reduced the probability by −28% (−564% to +71%).
• Overall, human factors contributed to a 2.75-fold increase in the probability of the 2022 EDBWE.
• Under future Shared Socioeconomic Pathway (SSP) scenarios (2021–2100), the likelihood of similar events rises significantly:
  • By the end of the 21st century (2081–2100), the probability of an event akin to the 2022 EDBWE is projected to be approximately 9 times greater under SSP1-2.6, 6 times greater under SSP2-4.5, and 11 times greater under SSP5-8.5, compared to historical climate conditions.
• The emergence time (ET) of anthropogenic climate change for the DBW precipitation is projected for 2035 under SSP1-2.6, 2079 under SSP2-4.5, and 2055 under SSP5-8.5.

Contributions

• Provides a quantitative attribution of the unprecedented 2022 extreme dragon boat water event in South China to anthropogenic climate change, distinguishing the roles of greenhouse gases and aerosols.
• Offers comprehensive future projections of the likelihood of similar extreme precipitation events under various Shared Socioeconomic Pathway (SSP) scenarios, including the estimation of emergence time.
• Delivers crucial insights for developing effective climate change mitigation and adaptation strategies in regions vulnerable to extreme precipitation.

Funding

• The National Natural Science Foundation of China (U21A6001, 42175173)
• Guang Dong Basic and Applied Basic Research Foundation (2023A1515240036)
• Project supported by Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai) (No. SML2024SP011)

Citation

@article{Li2025Human,
  author = {Li, Shenao and Cai, Hui and Zhang, Wenxuan and Liang, Wenjun and Wang, Kaixi and Chen, Dong and Qiao, Shaobo and Zhu, Xian},
  title = {Human influence on the unprecedented 2022 extreme dragon boat water event in South China: Insights from historical and projected perspectives},
  journal = {Weather and Climate Extremes},
  year = {2025},
  doi = {10.1016/j.wace.2025.100830},
  url = {https://doi.org/10.1016/j.wace.2025.100830}
}