London, 30 December 2025 (dpa/MIA) – Climate change caused many extreme weather events of the past year to be more likely or to manifest more strongly, according to a report by the World Weather Attribution (WWA) initiative published on Tuesday.

Global warming is already taking millions of people to the limits of their ability to adapt, the WWA says in its annual report for 2025.

"Each year, the risks of climate change become less hypothetical and more brutal reality," Friederike Otto, professor in Climate Science at the Centre for Environmental Policy at Imperial College London and co-founder of World Weather Attribution, says.

The team counted 157 extreme weather events in 2025: 49 floods, 49 heatwaves, 38 storms, 11 wildfires, seven droughts and three cold spells.

Events are included on the list only once they have passed a certain threshold, for example by causing more than 100 fatalities, by affecting more than a million people, or if a national or regional disaster is declared.

The WWA team examined 22 of the 157 events in depth, finding that 17 of these had become more likely or had been more severe due to climate change. For just five - all of them extreme rainfall - the results were inconclusive.

Among the other events were a seven-day heatwave in February in South Sudan with temperatures of up to 40 degrees Celsius. According to the analysis, temperatures would have reached a maximum of 36 degrees without climate change.

2025: Global warming above 1.5 degrees for third year in a row

Model calculations on the devastating wildfires in the north-west of the Iberian Peninsula in August indicated that climate change had made fires of this extent 40 time more likely.

Regarding the wildfires in Los Angeles in January, the team says that the fires claimed around 400 fatalities and that insured damage ran to $30 billion - the highest amount for wildfire damage ever - while the uninsured damage was probably much higher.

Climate change had raised the likelihood of these fires by 35%, the study found.

Turning to tropical cyclones and hurricanes, the team found that many of them were a category higher than they would have been without climate change.

Hurricane Melissa swept across Jamaica and Cuba in October with winds of up to 288 kilometres per hour, while without climate change, the speeds would have been 270 kilometres per hour.

Given global warming of 2 degrees by comparison with the pre-industrial era - the team puts the current increase at 1.3 degrees - top wind speeds would have reached 295 kilometres per hour under similar conditions.

Every tenth of a degree counts

According to the report, a rise of 1.5 degrees by comparison with the pre-industrial era will have been reached in 2025 for the third year in a row. The Paris Climate Agreement foresees limiting global warming to 1.5 degrees if possible. That target is now seen as unrealistic.

The team says, that if climate protection measures are implemented in full, the earth will heat up by 2.6 degrees, instead of 4 degrees.

The team makes clear that every tenth of a degree counts through investigations of heatwaves in the Amazon and in Burkina Faso and Mali. These events had become 10 times more likely since the Paris Climate Agreement was signed, it found - given a global temperature rise since then of 0.3 degrees.

"Decision-makers must face the reality"

Even if the effects of the El Niño phenomenon were particularly strong in 2024, in large regions in Central Asia and China, as well as in parts of Scandinavia, 2025 was the hottest year since 1995.

El Niño is caused by warmer waters in the tropical Pacific and influences global weather patterns through changes in air and sea currents.

The report shows that efforts to cut CO2 emissions are insufficient to prevent the global temperature rise and its worst effects, Otto says.

"Decision-makers must face the reality that their continued reliance on fossil fuels is costing lives, billions in economic losses, and causing irreversible damage to communities worldwide," she says.

Otto is among the most important scientists in attribution research, which investigates the contribution of climate change to extreme weather events. The scientists analyse how likely and how extreme the events would have been without anthropogenic warming since the start of the Industrial Revolution.

Photo: epa