‘Significant’ acceleration of global warming since 2015: study

Global warming has accelerated in a “statistically significant” way since 2015, according to a study published by the Potsdam Institute for Climate Impact Research (PIK).

“Over the past 10 years, the estimated warming rate has been around 0.35 °C per decade, depending on the dataset, compared with just under 0.2 °C per decade on average from 1970 to 2015,” the study found.

“This recent rate is higher than in any previous decade since the beginning of instrumental records in 1880,” it added.

The study relied on observational data on climate change from NASA, the National Oceanic and Atmospheric Administration (NOAA), and Berkeley Earth, a California-based non-profit research organisation.

Study co-author Grant Foster said that the researchers had “filtered out” natural influences likely to obscure the underlying temperature trend, such as the El Niño phenomenon, volcanic eruptions, and variations in solar activity.

In this way, “the ‘noise’ is reduced, making the underlying long-term warming signal more clearly visible,” Foster added.

“The adjusted data show an acceleration of global warming since 2015 with a statistical certainty of over 98 percent,” said Stefan Rahmstorf, PIK researcher and lead author of the study.

“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,” Rahmstorf added.

Scientists say the last 11 years have been the warmest ever recorded, with 2024 topping the podium and 2023 in second place.

“After correcting for the effects of El Niño and the solar maximum, 2023 and 2024, which were exceptionally warm years, become somewhat cooler, but remain the two warmest years since the beginning of instrumental records,” the PIK study says.

Scientific debate

The question of a potential increase in the rate of planetary warming has sparked debate within the scientific community.

Zeke Hausfather, a climatologist at Berkeley Earth, told AFP that “there is now pretty widespread (if not quite universal) agreement that there has been a detectable acceleration in warming in recent years”.

But the methods used in the PIK study to remove natural variability are “decidedly imperfect and will likely leave some remaining effects”, he added.

In 2024, a study published in the Communications Earth & Environment journal argued that the available data do not show a statistically robust recent acceleration of warming above and beyond the increase already observed since the 1970s.

Interviewed in 2025 by AFP, Robert Vautard, co‑chair of the IPCC working group on the scientific basis of climate change, said the recent records were “surprising” but not “aberrant” in light of earlier scientific estimates.

Beyond natural fluctuations, he particularly stressed the need to study the influence of global declines in aerosol emissions.

These particles, emitted by human activity, tend to cool the planet and partially offset warming by reflecting part of the sun’s radiation and altering cloud formation.

According to Hausfather, “it remains unclear how much of the additional warming over the past decade in particular is a forced response” — in other words, due to external factors that alter the climate in a lasting way, for example the continued increase in greenhouse gas emissions.

Hausfather also pointed to the “rapid reduction” in global emissions of sulphur dioxide, which “have been masking a portion of historical warming”.

That “unforced variability” was also a possible factor in the warming trend over the past decade, he added.

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© Agence France-Presse

Journal Reference:
Foster, G., & Rahmstorf, S., ‘Global warming has accelerated significantly’, Geophysical Research Letters 53, (5): e2025GL118804 (2026). DOI: 10.1029/2025GL118804

Article Source:
Press Release/Material by Delphine Paysant | AFP
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