The pace of global warming has nearly doubled since 2015, according to a landmark study published on March 6, 2026, in Geophysical Research Letters by the American Geophysical Union. Lead researchers Grant Foster, a retired statistician formerly of Tempo Analytics, and Stefan Rahmstorf of the Potsdam Institute for Climate Impact Research in Germany found that the warming rate jumped from approximately 0.2 degrees Celsius per decade between 1970 and 2015 to roughly 0.35 degrees Celsius per decade in the period from 2015 to 2025, representing a 75 percent increase with over 98 percent statistical confidence across all datasets analyzed.
The study drew on five independent global temperature records, including NASA GISS, NOAA, the Met Office Hadley Centre HadCRUT5, Berkeley Earth, and the Copernicus ERA5 reanalysis dataset. The researchers employed statistical filtering techniques to strip out short-term influences such as El Nino events, volcanic eruptions, and solar variations. Two independent analytical approaches confirmed the acceleration: a quadratic trend analysis and a breakpoint detection method that identified the shift as occurring between February 2013 and February 2014. All ten years since 2015 now rank among the warmest ever recorded, with the last three years holding the top positions.
The primary driver of the accelerated warming, according to the study, is the reduction of atmospheric aerosols resulting from international shipping fuel regulations that took effect around 2020. These regulations slashed sulfur emissions from maritime vessels by approximately 85 percent. While the aerosols had been reflecting sunlight back into space and helping to seed cooling clouds, they had simultaneously been causing severe air pollution. Their removal is estimated to prevent around 260,000 premature deaths annually but has unmasked the full warming effect of accumulated greenhouse gases in the atmosphere.
Rahmstorf described the phenomenon as a clean air paradox, explaining that improving air quality has inadvertently revealed the true extent of greenhouse gas warming that aerosol pollution had been partially concealing for decades. The findings carry significant implications for international climate targets. At the current rate of warming, the Paris Agreement threshold of 1.5 degrees Celsius above pre-industrial levels could be permanently exceeded before 2030. If the accelerated rate were to continue unchecked, projections suggest the planet could face approximately 4 degrees Celsius of warming by 2100.
However, Rahmstorf noted that this elevated warming rate may not persist into the next decade since no comparable aerosol reduction event is expected. He emphasized that how quickly Earth continues to warm ultimately depends on how rapidly the world reduces global carbon dioxide emissions to zero. Claudie Beaulieu of the University of California Santa Cruz cautioned that the observed acceleration may prove temporary rather than a permanent shift in the warming trajectory.
Michael Mann of the University of Pennsylvania offered a different perspective, contending that the underlying warming trend has remained roughly constant since the 1970s and questioning whether the recent spike constitutes a true long-term acceleration. The debate underscores the complexity of attributing short-term variations in warming rates to specific causes. Regardless of interpretation, the study reinforces that global temperatures continue to rise at an alarming pace and that aggressive emissions reductions remain critical.
The research has intensified calls among climate scientists and policymakers for immediate action to curb fossil fuel consumption and accelerate the transition to renewable energy sources. With the 1.5-degree threshold potentially within reach before the end of this decade, the window for meaningful intervention continues to narrow. The study serves as a stark reminder that even well-intentioned environmental regulations can produce unintended consequences when the broader system of atmospheric chemistry is not fully accounted for.
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