Overview
- Global monitors report 2025 ranked third-warmest on record, with the WMO estimating a 1.44°C rise above pre-industrial levels and noting the last 11 years are the warmest on record.
- Copernicus puts 2025 at 1.47°C above pre-industrial times and says the 2023–2025 average exceeded 1.5°C, while the WMO’s consolidated analysis places the three-year average at 1.48°C with a ±0.13°C uncertainty.
- Scientists identify the buildup of heat-trapping greenhouse gases as the dominant driver, with reduced aerosol cooling, weakened natural CO2 sinks, ENSO variability, and exceptionally warm seas amplifying recent heat.
- Despite a cooling La Niña at the start and end of the year, temperatures remained unusually high, underscoring the strength of the long-term warming trend.
- Separate research finds the oceans gained about 23 zettajoules of heat in 2025, intensifying risks tied to sea-level rise and extreme weather and reinforcing calls for early-warning systems and adaptation.