Climate scientists have issued a stark warning after confirming that 2025 ranks as one of the three hottest years ever recorded, pushing long-term global temperatures past a critical international limit for the first time.
A Critical Threshold Crossed
Research released on Tuesday 30 December 2025 by the World Weather Attribution (WWA) group reveals a sobering milestone. The three-year average global temperature has now surpassed 1.5 degrees Celsius (2.7 Fahrenheit) above pre-industrial levels. This is the crucial warming limit established by the 2015 Paris Agreement, which experts consider vital for preventing catastrophic environmental damage and saving lives worldwide.
Friederike Otto, co-founder of WWA and a climate scientist at Imperial College London, emphasised the urgency to The Associated Press. "If we don’t stop burning fossil fuels very, very quickly, very soon, it will be very hard to keep that goal," she stated, adding that "the science is increasingly clear." The record temperatures persisted despite the presence of La Nina, a natural Pacific Ocean cooling phenomenon that typically tempers global heat.
Deadly Extremes Linked to Human Activity
The analysis followed a year of severe climate impacts across the globe, driven primarily by the continued burning of oil, gas, and coal. WWA scientists identified 157 of the most severe extreme weather events in 2025, selecting 22 for close study.
Heat waves were the deadliest extreme weather events of the year. Researchers found some 2025 heat waves were ten times more likely than they would have been just a decade ago due to human-caused climate change. "The heat waves we have observed this year are quite common events in our climate today, but they would have been almost impossible to occur without human-induced climate change," Otto explained.
Other devastating events included prolonged drought fuelling wildfires in Greece and Turkey, torrential rains and fatal flooding in Mexico, Super Typhoon Fung-wong forcing over a million evacuations in the Philippines, and monsoon-driven floods and landslides in India.
Limits of Adaptation and Stalled Global Action
The report highlighted a growing "limits of adaptation" crisis, where the increasing frequency and severity of extremes outpace communities' ability to respond. It cited Hurricane Melissa, which intensified rapidly, battered Jamaica, Cuba, and Haiti, and left small island nations unable to cope with the scale of damage.
This scientific warning comes amidst faltering global political progress. The November 2025 UN climate talks in Brazil ended without a concrete plan to transition away from fossil fuels. While more adaptation funding was pledged, implementation will take time. Nations are diverging in their approaches: China is expanding renewables but also coal; European nations debate climate action versus economic growth; and the US Trump administration has favoured coal, oil, and gas over clean energy.
"The geopolitical weather is very cloudy this year with a lot of policymakers very clearly making policies for the interest of the fossil fuel industry rather than for the populations of their countries," Otto commented, also noting the challenge of widespread misinformation.
Andrew Kruczkiewicz of Columbia University's Climate School, not involved in the WWA study, noted that disasters are occurring in unprepared regions, intensifying faster and growing more complex. "On a global scale, progress is being made," he said, "but we must do more."
