EU and US climate analyses show 2025 was the third-warmest year on record, extending an 11-year run of exceptional heat. The three-year average for 2023–2025 exceeded 1.5°C above pre-industrial levels for the first time. Researchers warn 2026 is likely to remain very warm, and point to stalled emissions cuts plus changes such as reduced ship-fuel sulfur as factors that may have amplified recent warming.
2025 Third-Hottest Year On Record — 2023–2025 Average Tops 1.5°C; 2026 Outlook Grim
The last 11 years have now been the warmest ever recorded (Thibaud MORITZ)(Thibaud MORITZ/AFP/AFP)
Scientists with the EU's Copernicus Climate Change Service and the California-based non-profit Berkeley Earth reported that 2025 was the third-warmest year ever recorded, extending an unprecedented 11-year streak of record heat. The findings heighten concern about continued warming, with little relief expected in 2026.
Key Findings
Copernicus and Berkeley Earth highlighted several alarming statistics: global temperatures in 2025 were about 1.47°C above pre-industrial levels, while 2024 registered roughly 1.6°C. For the first time, the three-year average from 2023 to 2025 exceeded 1.5°C above pre-industrial times, a milestone with strong symbolic and scientific significance.
Berkeley Earth called the 2023–2025 warming spike "extreme" and said it suggests an acceleration in the rate of the Earth's warming.
Regional Impacts
About 770 million people experienced record-warm annual conditions where they live in 2025, and no region recorded a record-cold annual average, Berkeley Earth reported. The Antarctic had its warmest year on record, and the Arctic recorded its second-hottest year. Copernicus data also show Central Asia, the Sahel and parts of northern Europe experienced their hottest years on record in 2025.
2026 Outlook
Both agencies warned that the trend is likely to continue. Carlo Buontempo, director of the Copernicus Climate Change Service, noted that if a warming El Nino emerges, 2026 could be another record-breaking year. Berkeley Earth estimated 2026 is most likely to be close to 2025, perhaps the fourth-warmest year since 1850.
Drivers And Contributing Factors
Greenhouse gas emissions remain the dominant driver of long-term warming, but scientists say other factors may have amplified the recent temperature spike. Berkeley Earth chief scientist Robert Rohde pointed to changes such as international rules that cut sulfur in ship fuel from 2020. Lower sulfur dioxide emissions reduce reflective aerosols in the atmosphere, which can slightly reduce a cooling effect and thus contribute indirectly to warming.
The reports also noted that emissions reductions have stalled or reversed in some developed countries. The Rhodium Group found US emissions rose last year after two years of decline, and progress slowed in countries including Germany and France. Separately, political developments such as announced plans to withdraw the United States from core UN climate agreements may complicate global cooperation on emissions reductions.
What This Means
The 2023–2025 exceedance of the 1.5°C threshold for a rolling three-year average does not mean the long-term Paris Agreement goal is void, but it underscores how close the world is to sustained overshoot and how urgent deeper, faster emissions cuts are to limit the duration and extent of warming. Scientists emphasize that rapid mitigation and policy action can still reduce future risk and shorten any period of overshoot.
Sources: Copernicus Climate Change Service, Berkeley Earth, Rhodium Group, United Nations statements.
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