The study was conducted by a team of researchers at UC Santa Cruz, Clemson University, and the National Oceanic and Atmospheric Administration’s Geophysical Fluid Dynamics Laboratory. Led by Claudie Beaulieu, associate professor of ocean sciences at UC Santa Cruz, the team analyzed multiple independent observational datasets of surface temperature spanning the period from 1970 to 2024. By applying advanced statistical modeling techniques to this wealth of data, the researchers were able to identify coherent spatial and temporal patterns in the way warming rates have shifted across the globe over more than five decades.

At the heart of the analysis is a technique known as changepoint detection, in which statistical models are fitted at each individual grid point on the planet’s surface to determine whether and when the underlying rate of warming has changed. This approach goes beyond simply asking whether global mean temperature is accelerating; it asks where on Earth those accelerations have emerged, and precisely when they began. The result is a kind of statistical map of the planet’s warming behavior, one that reveals the unevenness hidden beneath the smooth curve of the global average.

The most striking finding concerns the Northern Hemisphere’s mid-latitudes, where the most recent accelerations in warming are most prominent. Southeast China stands out as the region with the most pronounced changes in warming rate, followed closely by the Gulf of Mexico. The timing of these shifts is not uniform, however. According to the researchers, regional speed-ups have emerged in distinct waves, with onset timings ranging from the 1980s through the 2010s depending on the geographical area, a staggered pattern that underscores how differently the climate system is responding across space and time.

“What we wanted to do is provide a clearer, region-by-region picture of where warming is actually accelerating—and when it began,” said lead author Claudie Beaulieu, associate professor of ocean sciences at UC Santa Cruz. “Our study shows that regional speed-ups have emerged in distinct waves, with onset timings ranging from the 1980s through the 2010s depending on the geographical area.”

The new work builds on and extends previous research by members of the same team, which assessed whether an acceleration could be detected in global mean temperature. That global-scale question has become central to a lively scientific debate, as each successive year seems to shatter temperature records and as scientists grapple with whether the pace of warming itself is changing. The regional analysis, however, provides a far more nuanced picture. In addition to southeast China and the Gulf of Mexico, the team identified several other regions experiencing recent accelerated warming, including the eastern Mediterranean, Bolivia, the North Pacific, and New Zealand. The breadth of this list demonstrates that warming accelerations are not confined to any single climate zone or continent.

While the study focuses on statistically mapping these regional shifts rather than assigning definitive causes to each one, the researchers note that localized drivers may play a role in some, but not all, of the detected speed-ups. One particularly compelling clue lies in the timing of the changes. The onset timings detected by the team are consistent with declining sulfur-dioxide emissions from coal-fired power plants in China. Sulfur dioxide aerosols have a cooling effect on the atmosphere by reflecting sunlight, so reductions in aerosol pollution can unmask additional warming that was previously suppressed. This suggests that at least some of the dramatic acceleration observed in southeast China may be linked to the region’s dramatic improvements in air quality, although the researchers emphasize that pinpointing the physical mechanisms behind every regional speed-up will require further studies.

The methodological rigor of the study is central to its value. “Fitting our models at each grid point allows us to identify regions with similar warming behavior,” said co-author Rebecca Killick, professor of statistics at Clemson University and honorary professor at Lancaster University. “This is important for local communities to understand how increased warming will have local impacts.” By detecting changes in warming rates at such fine spatial resolution, the approach transforms an abstract global statistic into actionable, place-based information that communities, planners, and policymakers can use to assess their own exposure to a changing climate.

The implications of these findings extend well beyond academic debate. A key impact of warming accelerations is the shifting baseline for the frequency and severity of extreme events such as heatwaves. While continued steady warming alone causes this baseline to shift, any increase in the rate of warming can lead to a disproportionate increase in the likelihood of record-breaking events. In other words, when warming speeds up, the probability of unprecedented heat extremes does not merely rise in step—it can jump disproportionately, placing additional stress on infrastructure, agriculture, and human health. Identifying the specific regions and timings of warming shifts therefore provides crucial context for regional climate-impact assessments, adaptation strategies, and environmental planning.

The researchers also emphasize questions of equity and ecological vulnerability. Regions with large populations and low socioeconomic development are especially vulnerable to accelerated warming and the accompanying changes in temperature extremes, meaning that the regions identified in the study may face compounded risks. Ecosystems, too, are often more sensitive to rapid temperature shifts than to gradual changes, and the staggered timing of accelerations documented in the study could help ecologists anticipate where and when biological systems are most likely to be pushed past critical thresholds. “We hope that this work revealing when and where these accelerations have occurred in the past, along with an interactive public dashboard to enable the public to continue monitoring local rates of warming by clicking on a map, will provide tools and support to better anticipate localized impacts and target efforts where they are most needed,” Beaulieu said. The dashboard allows anyone to explore local warming rates directly, translating a sophisticated statistical analysis into a resource accessible to the general public.

Funded by the National Science Foundation through CAREER Grant AGS-2143550, the study represents a significant step forward in understanding the texture of global warming. By combining more than five decades of observational data from multiple datasets with sophisticated changepoint statistics applied at every point on the globe, the research moves the conversation about warming acceleration from a single global number to a rich, spatially resolved narrative. As record temperatures continue to make headlines and the debate over acceleration intensifies, this work makes clear that the answer to the question of whether warming is speeding up is neither a simple yes nor a simple no. It is a resounding yes in some places, at some times—and the where and the when matter enormously for the people and ecosystems living through them. The authors declare no competing interests, and the research was published in Nature Communications on September 22, 2026, under the title “Space-time signatures of surface warming accelerations since 1970.”

Subject of Research: Regional and temporal patterns of surface warming accelerations worldwide since 1970

Article Title: Unveiling the unevenness of global warming

Article References: Unveiling the unevenness of global warming. (n.d.). Original publication

Image Credits: AI Generated

DOI: Not provided

Keywords: global warming, climate acceleration, surface temperature, changepoint analysis, southeast China, Gulf of Mexico, aerosol emissions, extreme heat events, regional climate, Nature Communications, climate adaptation, temperature datasets