Scientists tally over 100 severe weather events in 2025

From forest infernos in Turkey to record-shattering heat and rapidly intensifying storms, 2025 delivered a relentless drumbeat of extremes that scientists say bears the unmistakable fingerprints of human-driven climate change. New analysis finds the year ranked among the three hottest on record, and, for the first time, the global three-year temperature average climbed beyond the 1.5 degrees Celsius threshold referenced in the Paris Agreement—a milestone experts long warned would sharply raise risks to people and ecosystems.

A year of extremes despite a cooling Pacific

Researchers with the World Weather Attribution initiative reported that temperatures remained unusually high even though a La Niña—an intermittent cooling pattern in the Pacific that can dampen global heat—was in play for parts of the year. Their conclusion: continued combustion of coal, oil, and gas kept greenhouse gases rising, overwhelming natural variability and loading the dice toward dangerous extremes.

By WWA’s count, at least 157 events in 2025 met the bar for “most severe,” a designation reserved for disasters that caused more than 100 deaths, affected over half of a region’s population, or prompted a state of emergency. Of those, 22 were subjected to in-depth attribution studies to quantify how much more likely or intense they became due to human-caused warming.

Heat waves dominate the global toll

Heat was the deadliest hazard of the year. The analysis indicates that several 2025 heat waves were roughly 10 times more likely than they would have been just a decade ago because of rising greenhouse gas concentrations. Many of these events would have been exceedingly rare—if not virtually impossible—without the additional warming from human activities.

Such temperatures can push societies past their coping capacity, straining health systems, power grids, and water supplies. The reality for city dwellers and rural communities alike: extreme heat that used to be considered exceptional is now entering the realm of the routine.

Fires, floods, and storms: a global snapshot

Prolonged drought primed landscapes in southern Europe and the eastern Mediterranean, contributing to destructive wildfires in Greece and Turkey, including blazes near Cavuslar village in Türkiye’s Karabük province in late July. At the other end of the hydrological spectrum, torrential rains in Mexico triggered lethal flooding and landslides, leaving dozens dead and many missing.

Across the western Pacific, Super Typhoon Fung-wong forced mass evacuations in the Philippines, while a hypercharged monsoon season drenched parts of India, unleashing more floods and slope failures. In the Caribbean, Hurricane Melissa intensified so rapidly that it complicated forecasting and advanced preparations, battering Jamaica, Cuba, and Haiti. Scientists warn that the accelerating pace and compounding nature of such hazards are pushing communities toward the “limits of adaptation,” where early warnings, evacuation routes, and relief capacity struggle to keep pace.

Adaptation stretched, warning systems lagging

Disasters are striking places unaccustomed to them and escalating faster when they do. This demands earlier, more targeted alerts, along with new recovery and rebuilding approaches that anticipate back-to-back shocks. Without faster deployment of heat action plans, flood defenses, wildfire risk reduction, and resilient infrastructure, avoidable losses will keep mounting.

Policy gap: ambition versus physics

Global negotiations this year offered mixed signals. International climate talks in Brazil concluded without a clear commitment to phase out fossil fuels, even as financial pledges to help nations adapt grew. The support, while welcome, will take time to reach the front lines and is not yet scaled to the risks at hand.

Many experts now acknowledge that warming is likely to overshoot 1.5 C in the near term. They also stress that every tenth of a degree matters—and that stabilizing temperatures later in the century remains technically feasible if emissions fall steeply and quickly, paired with expanded carbon sinks and restored ecosystems.

What needs to happen next

• Rapidly cut fossil fuel use and accelerate clean energy deployment, efficiency, and electrification.
• Scale up life-saving measures: heat early warning systems, cooling centers, urban shade and green space, drought planning, and wildfire preparedness.
• Invest in nature-based solutions—from wetlands that buffer floods to forests that store carbon and cool local climates.
• Strengthen risk-informed planning so that homes, roads, and power systems can withstand intensifying extremes.
• Ensure climate finance reaches vulnerable communities quickly and transparently, with local leadership in design and delivery.

The message from 2025 is blunt: the climate is changing faster than many systems are built to handle. Yet the same science that traces today’s disasters to human causes also illuminates a way out. Swift emissions cuts and smarter adaptation can still curb the worst impacts, protect lives and livelihoods, and keep options open for the decades ahead.