León‐FonFay et al. (2026) A country-level storyline attribution of global warming on heat-related extremes in South America

Identification

• Journal: Weather and Climate Extremes
• Year: 2026
• Date: 2026-09-24
• Authors: Dalena León‐FonFay, Reyko Schachtschneider, Linda van Garderen, Frauke Feser
• DOI: 10.1016/j.wace.2026.100961

Research Groups

• Institute of Coastal Systems, Helmholtz-Zentrum Hereon, Germany
• University of Hamburg, Germany
• GFZ Helmholtz Centre for Geosciences, Potsdam, Germany
• Institute for Marine and Atmospheric Research, Utrecht University, the Netherlands

Short Summary

This study uses a storyline approach to attribute global warming to heat-related extremes in South America. The results show that under pre-industrial conditions, few countries would have experienced heat extremes, but with continued warming, many countries will experience increasingly persistent heat and drought conditions.

Objective

• Investigate the influence of anthropogenic global warming on heat-related extremes in South America at a national scale.
• Attribute the changes in frequency and seasonality of warm days, warm nights, hot-humid days, and duration and extent of droughts to human-induced global warming.

Study Configuration

• Spatial Scale: Country-level analysis for 12 countries in South America (Argentina, Bolivia, Brazil, Chile, Colombia, Ecuador, French Guiana, Guyana, Paraguay, Peru, Suriname, Uruguay).
• Temporal Scale: Decadal-scale analysis of the 2015-2024 period.

Methodology and Data

• Models used: Spectrally nudged storylines using the ECHAM6.3 atmospheric model.
• Data sources: ERA5 reanalysis data, NCEP reanalysis data, CMIP6 MPI-ESM-HR model's historical run or SSP5-8.5 scenario.

Main Results

• Under pre-industrial conditions, few countries would have experienced heat extremes.
• With continued warming, many countries will experience increasingly persistent heat and drought conditions.
• The frequency of warm days and nights increases with global warming, with tropical countries experiencing year-round warm-day conditions in a +4K world.
• Hot-humid days occur more frequently in tropical countries, but their impact is limited by national adaptation measures and local vulnerability factors.
• Extreme droughts become more frequent and widespread under global warming, with the Amazon rainforest standing out as a hotspot.

Contributions

• This study provides a systematic, country-level assessment of how anthropogenic global warming modifies the occurrence of heat-related extremes in South America.
• The results highlight the need for mitigation and adaptation planning to address the increasing frequency and severity of heat and drought events.

Funding

• This research was funded by the German Federal Ministry of Education and Research (BMBF) through the project "Climate Change and Human Health" (01LS1901A).
• Additional funding was provided by the Helmholtz Association through the program "Helmholtz Young Investigators Group" (VH-NG-1017).

Citation

@article{LeónFonFay2026countrylevel,
  author = {León‐FonFay, Dalena and Schachtschneider, Reyko and Garderen, Linda van and Feser, Frauke},
  title = {A country-level storyline attribution of global warming on heat-related extremes in South America},
  journal = {Weather and Climate Extremes},
  year = {2026},
  doi = {10.1016/j.wace.2026.100961},
  url = {https://doi.org/10.1016/j.wace.2026.100961}
}