Markus Donat

Human-induced climate change amplified the intensity and extent of the rainfall that affected Valencia during the October 2024 dana, according to a new attribution study involving several Spanish research centres. Using climate simulations, the study, published in Nature Communications, shows that present-day global warming conditions increased precipitation intensity by 21 %, expanded the area receiving more than 180 millimetres of rain by 56 %, and raised the total rainfall volume in the Júcar River basin by 19 % compared to a pre-industrial scenario. The authors highlight “the urgent need for effective adaptation strategies and improved urban planning to reduce the growing risks associated with extreme hydrometeorological events in a rapidly warming world.”

An Italian team has studied the factors that are increasing the frequency of massive floods in the Mediterranean region. According to their analysis, and in a context of climate change, a “dead end” effect is occurring in which mountains close to the sea block moisture and “trap” rain over the region. The article focuses on the floods suffered by the Emilia-Romagna region (Italy), but according to the authors, other Mediterranean areas with a similar geography, including Valencia and Catalonia, “could face the same risks and these events could become more frequent as the climate continues to change.” The results are published in Scientific Reports.  

A study by a team from the ClimaMeter project claims that the intensification of rainfall from the DANA that devastated Valencia and other regions on 29 October is mainly attributed to human-induced climate change. Natural climate variability, on the other hand, probably played a modest role. According to the analysis, this DANA was driven by very exceptional weather conditions. The work also shows that the DANA-like depressions that cause flooding in the southeastern peninsular are up to 15 % wetter than they were in the past. In addition, temperatures are up to 3°C warmer, which favours storm formation in these events over the Mediterranean basin. 

An attribution study by World Weather Attribution (WWA) concludes that the heatwaves in Europe and North America this July would have been "almost impossible" without climate change. Over the past few weeks, southern Europe, parts of the United States, Mexico and China have experienced severe heatwaves with temperatures exceeding 45 °C. The WWA report notes that in China the heatwave was at least 50 times more likely due to the climate crisis.