Global warming has shifted into a faster gear, according to a new analysis from the Potsdam Institute for Climate Impact Research (PIK) published in Geophysical Research Letters. After filtering out the natural temperature swings caused by El Niño, volcanic eruptions and solar activity, researchers found the first statistically significant evidence that the planet's long-term warming rate is accelerating.

Over the past decade, global temperatures have risen at an estimated 0.35°C per decade — compared with just under 0.2°C per decade from 1970 to 2015, and faster than any decade since instrumental records began in 1880. 'We can now demonstrate a strong and statistically significant acceleration of global warming since around 2015,' says Grant Foster, a US statistics expert and co-author.

The team analyzed five widely used global temperature datasets (NASA, NOAA, HadCRUT, Berkeley Earth, ERA5), removing 'noise' such as El Niño's temporary heat release from the tropical Pacific and volcanic particles that reflect sunlight. 'The adjusted data show an acceleration of global warming since 2015 with a statistical certainty of over 98 percent, consistent across all data sets examined and independent of the analysis method chosen,' explains lead author Stefan Rahmstorf. Two statistical approaches — a quadratic trend analysis and a piecewise linear model — independently pointed to the same shift, visible from about 2013–2015. Even after adjustment, 2023 and 2024 remained the two warmest years on record.

The study was designed to detect and measure the acceleration, not to explain it, though the authors note current climate models can produce such periods of speed-up. The implication is stark: 'If the warming rate of the past 10 years continues, it would lead to a long-term exceedance of the 1.5°C limit of the Paris Agreement before 2030,' says Rahmstorf. How quickly Earth keeps warming, he adds, ultimately depends on how rapidly global CO2 emissions from fossil fuels fall to zero.

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