New research led by UC Santa Cruz and involving Professor of Statistics at Clemson University and Lancaster University Emeritus Professor Rebecca Killick provides a clearer picture of where and when global warming is accelerating.

The years 2023 and 2024 were the two warmest years on record since global surface temperature observations began in 1850, intensifying debates over whether global warming is speeding up. Against this backdrop, the researchers analysed multiple surface-temperature datasets covering 1970 to 2024 to investigate whether warming has accelerated at different times and in different parts of the world.

“Researchers wanted to provide a clearer, region-by-region picture of where warming is actually accelerating - and when it began,” said Professor Rebecca Killick.

Published in the journal Nature Communications, the study ‘Space-time signatures of surface warming accelerations since 1970’, used statistical modelling to identify changes in warming rates and uncover regional patterns over time.

Rather than finding a single, uniform acceleration across the planet, the researchers found distinct regional patterns. Accelerated warming was particularly evident across parts of the Northern Hemisphere’s mid-latitudes, including southeast China and the Gulf of Mexico, while other regions showing more recent acceleration included the eastern Mediterranean, Bolivia, the North Pacific, and New Zealand.

The timing of these changes also varied considerably, with regional warming speed-ups emerging in waves from the 1980s through to the 2010s, depending on the location.

The researchers suggest that local factors may have contributed to some of these regional changes. In parts of China, for example, the timing of warming acceleration is consistent with declining sulphur dioxide emissions from coal-fired power plants. Reductions in aerosol pollution can affect the amount of sunlight reaching the Earth's surface and, in turn, influence regional warming.

However, the study focuses on identifying where and when warming rates have changed rather than establishing the causes of individual regional accelerations. The researchers say further work is needed to understand the physical mechanisms behind the different patterns.

These regional differences matter because the rate at which temperatures increase can influence the likelihood of extreme heat. While continued warming shifts the baseline for events such as heatwaves, a faster rate of warming can further increase the likelihood of record-breaking temperatures.

Understanding where warming is accelerating can therefore provide important context for regional climate-risk assessments, adaptation strategies, and environmental planning. The researchers highlight the particular importance of this for highly populated and socioeconomically vulnerable regions, as well as ecosystems that may be sensitive to rapid changes in temperature.

The team has also developed an interactive public dashboard, enabling the public to continue monitoring local rates of warming by clicking on a map and helping to better anticipate localised impacts and target efforts where they are most needed.

“Our models show that regional speed-ups have emerged in distinct waves, with onset timings ranging from the 1980s through to the 2010s depending on the geographical area,” said Professor Rebecca Killick. “This is important for local communities to understand how increased warming will have local impacts.”

The study was authored by researchers Claudie Beaulieu and Adelicia Johnson at UC Santa Cruz, Rebecca Killick at Clemson University and Lancaster University, and John Lanzante and Thomas Knutson from the NOAA Geophysical Fluid Dynamics Laboratory. The work was funded by the National Science Foundation CAREER Grant AGS-2143550.

https://doi.org/10.1038/s41467-026-77514-z