How climate change made deadly floods in Spain even worse

How climate change has made Spain’s deadly floods worse

By Jackie Flynn Mogensen edited by Claire Cameron

In October 2024, the Spanish region of Valencia was smothered by a downpour of biblical proportions. In just a few hours, more rain fell in the region than in an average year. The precipitation triggered a series of flash floods that washed away bridges and rail cars and even derailed a train. In Spain, more than 230 people were killed in the flood. At the time, scientists believed that climate change had fueled this event. Now a new study reveals just how much of this has been the case.

The study shows that due to climate change, the rate of intense precipitation was around 21 percent higher over a six-hour period in Valencia than it would have been without the influence of climate change.

The research is what’s called a climate attribution study: The science clearly shows that a changing climate will make extreme weather and disasters like floods and wildfires worse and more frequent. But it can be difficult to say exactly how much global warming influenced a specific event.

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In the new study, researchers used real data to simulate different flood scenarios and compared them to measurements of what the climate looked like before the widespread use of fossil fuels in the new study. In doing so, the researchers were able to determine not only that rainfall in Valencia was more intense due to climate change, but also that the deluge was more widespread due to global warming.

The area that received about seven inches or more of rain in 24 hours during the disaster was about 55 percent larger than the region that would have received that amount under pre-industrial conditions, the researchers found. Notably, 2024 was the hottest year on record.

The study was published Tuesday in the journal Natural communication.

The results show that the types of storms that researchers once predicted due to climate change are “already becoming evident,” the authors write. Ultimately, they highlight the “immediate need” to ensure cities are prepared for a possible onslaught of extreme weather resulting from climate change.

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