Understanding the 1.5°C Benchmark
The 1.5°C threshold is not an arbitrary number. It represents a key benchmark under the Paris Agreement on climate change, with scientists warning that exceeding it for prolonged periods would sharply increase the risks of extreme weather, ecosystem collapse, food insecurity, and displacement . The scientific community has repeatedly warned that warming beyond 1.5°C risks unleashing ever more severe climate change impacts and decreases adaptation options .
As IPCC Chair Jim Skea noted in a recent address: “It is now almost inevitable that global warming will exceed 1.5 degrees Celsius above pre-industrial levels in the not-too-distant future” . The IPCC’s findings show that beyond 1.5°C of warming, risks start to accelerate, with consequences including heat stress, more extreme weather events, flood risks, drought, reduced productivity in agriculture and fisheries, and threats to ecological systems .
Temporary vs. Sustained Breaches: A Critical Distinction
It is essential to understand that the 1.5°C levels specified in the Paris Agreement refer to long-term warming sustained over an extended period, typically assessed over 20 years . Individual years with annual global mean temperatures exceeding these levels do not mean that the long-term temperature goals of the Paris Agreement are out of reach .
However, temporary exceedances are expected to occur with increasing frequency as the underlying rise in global temperature approaches these levels . These temporary breaches are “expected to occur more frequently as global temperatures continue to rise” . The current trajectory suggests that sustained warming beyond 1.5°C is becoming increasingly difficult to avoid.
The Role of El Niño
The predicted development of El Niño conditions is expected to amplify these warming trends. Dr. Leon Hermanson, lead author of the WMO report, explained: “There is an El Niño predicted for the end of 2026, which increases the chances of the following year, 2027, being the next record-breaking year” .
The five-year predicted average temperature in the central tropical Pacific indicates a tendency towards El Niño conditions, particularly in 2027 and 2028 . Strong El Niño events, even without global warming, cause regional to continental disruption in precipitation patterns and increase flood risks. “This effect will be amplified considerably by the now nearly 1.5°C of global warming experienced as of 2026,” warned Dr. Daniel Swain of the California Institute for Water Resources .
Arctic Amplification: A Tipping Point
The Arctic region is warming at an alarming rate—far faster than the rest of the planet. Temperatures across the region during the next five northern hemisphere winters are forecast to average 2.8°C above the 1991-2020 baseline—more than three-and-a-half times the projected global average increase over the same period . This phenomenon, known as Arctic amplification, is ringing alarm bells among scientists.
Projections also indicate continued declines in Arctic sea ice, particularly in the Barents Sea, Bering Sea, and Sea of Okhotsk . Sea ice loss matters because it accelerates warming by reducing the Arctic’s ability to reflect sunlight, while also disrupting ecosystems, weather patterns, and livelihoods in polar regions .