Space-time signatures of surface warming accelerations since 1970.

With record-breaking temperatures over 2023-2024 and extreme events observed around the world, there is currently a debate in the scientific literature and media as to whether global warming is accelerating. Here we address this question from a regional perspective, determining regions where an increase in the rate of warming is detected in surface temperature observations. Our results show that there are coherent space-time systems of acceleration in warming and shift toward warming since 1970 that are consistent across multiple surface temperature datasets. We show that accelerated warming and warming onset have occurred in different regions and are mostly present at mid-latitudes of the Northern Hemisphere. There is notable variability in the onset of regional warming accelerations: the timings vary from the 1980s to 2010s. Our results provide some nuance on the ongoing debate about global warming acceleration by identifying the source regions experiencing changes in the rate of warming and their timings.