Regional warming in 2025 already close to 1.5°C-world levels, study finds

Regions across the world may already have experienced 90%–94% of the warming expected when global average temperature reaches 1.5°C above preindustrial levels, according to a study in Nature Climate Change. The same analysis estimates that 65%–76% of the warming expected at 2°C has already been realised. Regional warming in 2025 could not be statistically distinguished from that of a 1.5°C world, the authors report.

Why regional estimates matter

The Paris Agreement sets its temperature goals for the global average, but the warming felt in any one place can differ considerably from that figure. Pinning down regional change is hardest where historical thermometer records are sparse or missing, as in parts of Africa, South America and the polar regions. Those gaps make it difficult to say how close a given region is to the changes associated with a global threshold.

Combining observations with models

Francis Zwiers and colleagues merged historical observations of near-surface air temperature with simulations from several climate models. They worked across all 46 regions defined in the IPCC's sixth assessment cycle, which together cover every continent. For each region, the team estimated the externally driven warming since 1850–1900. They then compared it with the regional temperatures expected when global warming reaches 1.5°C and 2°C.

The estimates for 2025 put every region at roughly nine-tenths of the way to its 1.5°C-equivalent level, and about two-thirds to three-quarters of the way to its 2°C-equivalent level.

Attribution and geography

Human influence accounts for almost all of the regional warming in the analysis. Greenhouse gases were the main driver in every region. Aerosols and other human influences exerted a cooling effect that partly offset them.

The strongest warming was found at high northern latitudes:

• Russian Arctic: 3.3°C above baseline
• Northeast North America: 2.6°C
• Northwest North America: 2.4°C

The weakest warming appeared in ocean-dominated regions, including Southwest South America, South South America, Southeast Asia and New Zealand. The authors note that estimates were especially dependable for tropical regions, including much of Africa. Year-to-year temperature variability is small there, so the long-term warming signal is easier to separate from noise. This is a useful result for a continent where observational records are patchy.

Implications and caveats

The authors suggest the results could support regional adaptation planning and assessments of climate-related loss and damage, including in places with limited observational coverage. Because the findings indicate that conditions close to a 1.5°C world have effectively arrived at regional scale, they argue that adaptation is needed in every region, not only those with the largest warming.

The main stated limitation concerns the climate models. The analysis depends on the available set, which is relatively small and may not capture the full range of plausible climate responses. Regional estimates could therefore shift if a broader or differently constructed ensemble were used. The source does not detail how uncertainty varies between individual regions, so comparisons between them should be treated cautiously.

What comes next

For climate scientists, the work offers a framework for placing regions relative to global warming levels without relying solely on dense station records. Natural next steps include testing the approach with larger model ensembles, refining estimates in data-poor regions, and extending the same logic to variables beyond air temperature, such as precipitation and extremes, which often matter more directly for impacts. The study is by Tong Li and co-authors, with Zwiers named as the lead voice in the summary, and appears in Nature Climate Change (DOI: 10.1038/s41558-026-02790-y).

Source: Some regions may already be living in a 1.5°C warmer world (Phys.org, 10 November 2026).

Image: AI-generated illustration.