Battaglioli et al. (2025) Contrasting trends in very large hail events and related economic losses across the globe

Identification

• Journal: Nature Geoscience
• Year: 2025
• Date: 2025-12-29
• Authors: Francesco Battaglioli, Mateusz Taszarek, Pieter Groenemeijer, Tomáš Púčik, Anja T. Rädler
• DOI: 10.1038/s41561-025-01868-0

Research Groups

• European Severe Storms Laboratory (ESSL e.V., ESSL Services GmbH, ESSL Science and Training)
• Department of Meteorology and Climatology, Adam Mickiewicz University
• Munich Re

Short Summary

This study develops a global climatology of very large hail (≥5 cm) events from 1950 to 2023 and examines trends in their frequency and related economic impacts. It finds contrasting regional trends, with Europe experiencing a sharp rise in very large hail frequency linked to atmospheric instability, while the Southern Hemisphere sees declines, and attributes increasing economic losses in Europe to more frequent events, whereas in the USA and Australia, increasing exposure and vulnerability are the primary drivers.

Objective

• To evaluate globally the long-term trends of very large hail (VLH; ≥5 cm) events and their associated economic losses from 1950 to 2023, addressing existing knowledge gaps in global climatologies of such events.

Study Configuration

• Spatial Scale: Global, with a grid resolution of 0.25° × 0.25°. Specific regional analyses for Northern Argentina, Uruguay, Paraguay, southern Brazil, US Great Plains, South Africa, Europe (Germany, Austria, Benelux, Northern Italy), Australia, and parts of Asia.
• Temporal Scale: 1950 to 2023 (74 years), with atmospheric data processed at 3-hour intervals.

Methodology and Data

• Models used: Additive Regressive Convective Hazard Model (AR-CHaMo).
• Data sources:
  • Atmospheric reanalysis: ERA5 (European Centre for Medium-Range Weather Forecasts Reanalysis 5).
  • Lightning observations: Arrival Time Difference Network (ATDnet) for Europe, National Lightning Detection Data (NLDN) for USA, Global Position and Tracking Systems (GPATS) for Australia, Earth Networks Global Lightning Detection Network (ENGLN) for global lightning distribution.
  • Hail reports: European Severe Weather Database (ESWD), Storm Prediction Centre Storm Archive (USA), Australian Bureau of Meteorology.
  • Economic loss data: Munich RE's NatCatSERVICE database, normalized to 2019 levels of destructible wealth using Gross Domestic Product (GDP).

Main Results

• Global Hotspots: Northern Argentina is identified as the global hotspot for very large hail (VLH) events, followed by Uruguay, Paraguay, southern Brazil, the US Great Plains, and South Africa. Asia, Europe, and Australia show substantially lower frequencies.
• VLH Frequency Trends (1950–2023):
  • Northern Hemisphere: Exhibits widespread positive and significant trends, with Europe showing the sharpest rise (e.g., Northern Italy up to +0.03 events per decade), driven by increasing low-level moisture and atmospheric instability. Southern Canada and parts of Mexico also show increases.
  • Southern Hemisphere: Experiences notable declines, particularly in Northern Argentina (e.g., Mendoza with a mean of -29.8% since 2006) and South Africa (northeast, -0.02 events per decade), linked to reduced mid-level humidity and instability.
  • Asia: Generally small or non-existent trends, with localized positive trends in Pakistan, the Tibetan Plateau, and northeastern China.
• Correlation with Temperature: Europe shows a significant positive correlation between 2-meter temperature and VLH frequency (Spearman correlation r ≈ 0.7 in southern Europe), reflecting increased instability. Other regions show weaker, heterogeneous, or negative correlations.
• Economic Losses: Hail-related losses have increased in the USA, Australia, and Europe. In Europe, this rise is mainly due to more frequent VLH events, alongside growing exposure and vulnerability. In the USA and Australia, increasing exposure and vulnerability are the primary drivers, as VLH frequency trends do not correlate with the increase in losses.

Contributions

• Provides the first comprehensive global climatology and long-term trend analysis (1950–2023) of very large hail (≥5 cm) events and their associated economic impacts.
• Identifies contrasting regional trends in VLH frequency across the globe, attributing these to specific atmospheric drivers such as changes in moisture and instability.
• Differentiates the primary drivers of increasing economic losses from hail across regions, highlighting the role of meteorological factors in Europe versus socio-economic factors (exposure and vulnerability) in the USA and Australia.
• Emphasizes the critical need for tailored regional risk management strategies that consider both climatic drivers and socio-economic vulnerabilities.
• Utilizes a robust statistical model (AR-CHaMo) with high-resolution reanalysis data (ERA5) and extensive observational datasets to overcome previous limitations in global hail research.

Funding

• Polish National Science Centre (grant no. 2020/39/D/ST10/00768)
• Poznan Supercomputing and Networking Centre (grant no. 648)
• Munich RE

Citation

@article{Battaglioli2025Contrasting,
  author = {Battaglioli, Francesco and Taszarek, Mateusz and Groenemeijer, Pieter and Púčik, Tomáš and Rädler, Anja T.},
  title = {Contrasting trends in very large hail events and related economic losses across the globe},
  journal = {Nature Geoscience},
  year = {2025},
  doi = {10.1038/s41561-025-01868-0},
  url = {https://doi.org/10.1038/s41561-025-01868-0}
}