Three-Year Global Heat Average Tops 1.5°C as 2025 Ranks Among Hottest on Record

Overview

• A World Weather Attribution assessment tallies 157 severe extreme events in 2025, with 22 analyzed in depth, and identifies heatwaves as the year’s deadliest hazards.
• Attribution studies report many 2025 heatwaves became far more likely or would have been nearly impossible without human-driven warming from continued fossil-fuel use.
• Persistently high temperatures during a La Niña year underscore the strength of the underlying anthropogenic warming signal.
• Reported impacts span deadly floods in Mexico, drought-fueled wildfires in Greece and Turkey, Super Typhoon Fung-wong in the Philippines, and the rapidly intensifying Hurricane Melissa in the Caribbean.
• UN climate talks in Brazil concluded without a fossil-fuel phaseout plan as policies diverge, with China expanding renewables while adding coal and the U.S. government backing coal, oil and gas, as scientists urge global net-zero by 2040–2045 to reduce tipping risks such as Amazon dieback.