Climate change unleashed: physical-based attribution analysis proves human-induced amplification of Valencia's deadly flooding

Climate change unleashed: physical-based attribution analysis proves human-induced amplification of Valencia's deadly flooding | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Article Climate change unleashed: physical-based attribution analysis proves human-induced amplification of Valencia's deadly flooding Carlos Calvo-Sancho, Javier Díaz-Fernández, Juan J. González-Alemán, and 8 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-6709965/v1 This work is licensed under a CC BY 4.0 License Status: Published Journal Publication published 17 Feb, 2026 Read the published version in Nature Communications → Version 1 posted You are reading this latest preprint version Abstract Global warming intensifies the hydrological cycle, increasing heavy rainfall events worldwide. In October 2024, Valencia (Spain) experienced rainfall accumulations in a few hours surpassing annual averages (771.8 mm in Turís official weather station) and record-breaking in one hour in Spain (184.6 mm), which promoted devastating flash-floods. This event resulted in 228 fatalities and was the major weather event in losses for contemporary Spain. Here we present a physical-based attribution study using the WRF model sourced with CMIP6 models to assess the contribution of anthropogenic climate change (ACC) to rainfall intensity, moisture content, and storm dynamics (i.e., diabatic heating, vertical motions, microphysical processes). Observed climate change led to more intense precipitation and a greater extent of this extreme rainfall event by +20% C-1 in 1-h rainfall rate, consistent with Clausius-Clapeyron scaling. Enhanced availability of atmospheric water vapor due to higher Mediterranean and subtropical North Atlantic SST played a central role, while CAPE, diabatic heating, and stronger vertical velocities boosted the convective processes. A deeper warm cloud layer and elevated graupel concentration reveal microphysical mechanisms that enhanced precipitation volumes in a warmer climate. These results demonstrate that ACC intensifies flash-flood risks in the Mediterranean region, and in this particular case, intensified the 6-h rainfall rate by 21%, amplified the 180 mm total rainfall area by 55% and increased the volume of total rain within the river Jucar catchment by 19% compared to the pre-industrial era. This study highlights the urgent need for effective adaptation strategies and improved urban planning to reduce the growing risks of hydrometeorological extremes in a rapidly warming world. Earth and environmental sciences/Climate sciences/Climate change/Attribution Earth and environmental sciences/Climate sciences/Atmospheric science/Atmospheric dynamics Extreme rainfall Physical-based attribution Convection Storm dynamics Western Mediterranean Full Text Additional Declarations There is NO Competing Interest. Cite Share Download PDF Status: Published Journal Publication published 17 Feb, 2026 Read the published version in Nature Communications → Version 1 posted You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. We do this by developing innovative software and high quality services for the global research community. Our growing team is made up of researchers and industry professionals working together to solve the most critical problems facing scientific publishing. Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-6709965","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Article","associatedPublications":[],"authors":[{"id":465255887,"identity":"62f608c9-b0ad-4cfc-9c3e-623205736ab4","order_by":0,"name":"Carlos Calvo-Sancho","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAABD0lEQVRIie2PsWrDMBCGTwjcRUarssSvcKbQKaSvYmNQl9IlS8BDEgLK6NWlfYj2DRwE9uLS1ZAOnjJ18ANoqOsQ0kG4dOugbzkd3Kf7D8Dh+J+QYihX514AaX9zTgq9KBT/rHhibJzv3tqiMxDwLQtbMPMH/rQtU1/NgfPCqoj6DvePCsJcs2skKlmIj1IefJXAJI+sCoIE7a8hAu1JQdY0fhH3NwdWU8DGHgz5ETQzEAXfCpjVoCxYvYLbd3swFP0W5kGEmpb94XpQKFvqPoA9mGiO0N8iwldNNcaqivNGJpPnZcVEY1d4JknbmVkwrTab/pHGWZ7su09MpzyzBzsvO5Wf37KxeYfD4XCM8wW41FbhbEIRjwAAAABJRU5ErkJggg==","orcid":"https://orcid.org/0000-0003-2457-9793","institution":"Universidad de Valladolid","correspondingAuthor":true,"prefix":"","firstName":"Carlos","middleName":"","lastName":"Calvo-Sancho","suffix":""},{"id":465255888,"identity":"f9c6c8c5-8950-4cc7-9df2-e574158d641c","order_by":1,"name":"Javier Díaz-Fernández","email":"","orcid":"","institution":"Universidad de Valladolid","correspondingAuthor":false,"prefix":"","firstName":"Javier","middleName":"","lastName":"Díaz-Fernández","suffix":""},{"id":465255889,"identity":"9023124a-47bf-49ee-915a-b52bf979a5d4","order_by":2,"name":"Juan J. 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In October 2024, Valencia (Spain) experienced rainfall accumulations in a few hours surpassing annual averages (771.8 mm in Turís official weather station) and record-breaking in one hour in Spain (184.6 mm), which promoted devastating flash-floods. This event resulted in 228 fatalities and was the major weather event in losses for contemporary Spain. Here we present a physical-based attribution study using the WRF model sourced with CMIP6 models to assess the contribution of anthropogenic climate change (ACC) to rainfall intensity, moisture content, and storm dynamics (i.e., diabatic heating, vertical motions, microphysical processes). Observed climate change led to more intense precipitation and a greater extent of this extreme rainfall event by +20% C-1 in 1-h rainfall rate, consistent with Clausius-Clapeyron scaling. Enhanced availability of atmospheric water vapor due to higher Mediterranean and subtropical North Atlantic SST played a central role, while CAPE, diabatic heating, and stronger vertical velocities boosted the convective processes. A deeper warm cloud layer and elevated graupel concentration reveal microphysical mechanisms that enhanced precipitation volumes in a warmer climate. \r\n\r\nThese results demonstrate that ACC intensifies flash-flood risks in the Mediterranean region, and in this particular case, intensified the 6-h rainfall rate by 21%, amplified the 180 mm total rainfall area by 55% and increased the volume of total rain within the river Jucar catchment by 19% compared to the pre-industrial era. This study highlights the urgent need for effective adaptation strategies and improved urban planning to reduce the growing risks of hydrometeorological extremes in a rapidly warming world.","manuscriptTitle":"Climate change unleashed: physical-based attribution analysis proves human-induced amplification of Valencia's deadly flooding","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2025-06-04 03:22:13","doi":"10.21203/rs.3.rs-6709965/v1","editorialEvents":[],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"nature-communications","isNatureJournal":true,"hasQc":false,"allowDirectSubmit":false,"externalIdentity":"NCOMMS","sideBox":"Learn more about [Nature Communications](http://www.nature.com/ncomms/)","snPcode":"","submissionUrl":"https://mts-ncomms.nature.com/","title":"Nature Communications","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"ejp","reportingPortfolio":"Nature Communications","inReviewEnabled":true,"inReviewRevisionsEnabled":false}}],"origin":"","ownerIdentity":"6be19c97-c59c-43ae-9a58-64b38e910389","owner":[],"postedDate":"June 4th, 2025","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"published-in-journal","subjectAreas":[{"id":49389246,"name":"Earth and environmental sciences/Climate sciences/Climate change/Attribution"},{"id":49389247,"name":"Earth and environmental sciences/Climate sciences/Atmospheric science/Atmospheric dynamics"}],"tags":[],"updatedAt":"2026-02-18T08:06:21+00:00","versionOfRecord":{"articleIdentity":"rs-6709965","link":"https://doi.org/10.1038/s41467-026-68929-9","journal":{"identity":"nature-communications","isVorOnly":false,"title":"Nature Communications"},"publishedOn":"2026-02-17 05:00:00","publishedOnDateReadable":"February 17th, 2026"},"versionCreatedAt":"2025-06-04 03:22:13","video":"","vorDoi":"10.1038/s41467-026-68929-9","vorDoiUrl":"https://doi.org/10.1038/s41467-026-68929-9","workflowStages":[]},"version":"v1","identity":"rs-6709965","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-6709965","identity":"rs-6709965","version":["v1"]},"buildId":"XKTyCvWXoU3ODBz1xrDgd","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}