Warren (2026) Extreme climate outcomes could still occur with just 2 °C of global warming

Identification

• Journal: Nature
• Year: 2026
• Date: 2026-03-25
• Authors: Rachel Warren
• DOI: 10.1038/d41586-026-00640-7

Research Groups

• Tyndall Centre for Climate Change Research, University of East Anglia, Norwich, UK (Rachel Warren)

Short Summary

This News & Views article highlights that even if global warming is limited to 2 °C above pre-industrial levels, extreme climate impacts, such as drought and flooding, could still occur at levels often predicted for much higher warming, emphasizing the need for policy to consider worst-case scenarios.

Objective

• To underscore that moderate global warming (2 °C) does not preclude extreme climate outcomes, advocating for a precautionary approach in climate risk assessments and policy.

Study Configuration

• Spatial Scale: Global, with a focus on key socio-ecological systems such as highly populated areas, global breadbasket regions (high grain production), and forests.
• Temporal Scale: Projections for various global warming levels (2 °C, 2.5 °C, 3 °C, 4 °C) compared to pre-industrial conditions.

Methodology and Data

• Models used: Ensemble of global climate models from the World Climate Research Programme’s (WCRP) Coupled Model Intercomparison Project Phase 6 (CMIP6).
• Data sources: Outputs from CMIP6 models, used to map variations in spatial patterns of climate-change projections.

Main Results

• Even with a 2 °C increase in global average temperature, worst-case outcomes for climate-related hazards (e.g., heavy five-day precipitation, soil-moisture deficit in breadbasket regions, wildfire-conducive weather) can be more extreme than the multi-model average predictions for 3 °C or even 4 °C of warming.
• The study introduced a "global climatic impact-driver" to quantify the projected change in exposure to each hazard for a given warming level, ranking models by these values to identify worst and best potential outcomes.
• This indicates that a precautionary approach, aiming for warming well below 2 °C, is necessary to avoid these extreme outcomes with high confidence.

Contributions

• This article synthesizes and highlights the critical finding that low-probability, high-impact climate outcomes must be considered in risk assessments, rather than solely focusing on most-likely average projections.
• It directly compares average and extreme climate risk outcomes across different global warming levels, providing a clearer picture of potential severe impacts.
• It emphasizes the quantification of exposure of key socio-ecological systems (e.g., global food security, ecosystem functioning) to climatic hazards in specific, important locations.
• The methodology and findings can inform future Intergovernmental Panel on Climate Change (IPCC) "burning embers" diagrams, ensuring a more comprehensive assessment of climate risks.

Funding

Not specified in this News & Views article.

Citation

@article{Warren2026Extreme,
  author = {Warren, Rachel},
  title = {Extreme climate outcomes could still occur with just 2 °C of global warming},
  journal = {Nature},
  year = {2026},
  doi = {10.1038/d41586-026-00640-7},
  url = {https://doi.org/10.1038/d41586-026-00640-7}
}