Missed Reports of Extreme Heat Events Exacerbate Vulnerability and Losses

Missed Reports of Extreme Heat Events Exacerbate Vulnerability and Losses | 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 Missed Reports of Extreme Heat Events Exacerbate Vulnerability and Losses Haozhi Pan, Shiyu Liang, Yiming Yang, Ye Zheng, Chaofan Sun, Shenghao Yan, and 9 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-9186502/v1 This work is licensed under a CC BY 4.0 License Status: Under Review Version 1 posted You are reading this latest preprint version Abstract Climate risks are systematically under-observed in the world’s most vulnerable regions, compounding exposure by delaying preparedness and adaptation. Using 2.1 million news articles across 184 countries and 40 languages, combined with AI-assisted geolocation and human-in-the-loop validation, we expose global under-reporting of extreme heat events. We find that only a tiny fraction of identified extreme heat events enters widely used global disaster databases, while 63.38% remain unreported even across the most comprehensive global and local news coverage. Under-reporting is concentrated in places like equatorial Africa, the Amazon basin, small island states, such as the Caribbean, and polar adjacent regions, where limited early warning capacity, high vulnerability, and linguistic distance from dominant languages intersect. Under the high-emissions scenario SSP5-8.5, by 2050, the largest future heat burdens are concentrated in highly vulnerable countries that coincide with the most severe under-reporting of extreme heat. These countries are projected to incur economic losses 60.09% higher and mortality-related losses 46.40% higher than better-reported countries. Yet pervasive under-reporting suggests that even these severe loss projections remain conservative for regions with the highest vulnerability, reinforcing the urgency of loss-and-damage action. Scientific community and society/Social sciences/Climate change/Climate-change impacts/Governance Earth and environmental sciences/Climate sciences/Climate change/Climate-change impacts/Governance Scientific community and society/Developing world Scientific community and society/Social sciences/Communication Extreme heat Media reporting bias Climate vulnerability Multilingual large-language models Climate Data Justice Full Text Additional Declarations There is NO Competing Interest. Supplementary Files ReportingSummary.pdf Reporting Summary ExtremeLLMSM260321.pdf Supplementary Materials Cite Share Download PDF Status: Under Review 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-9186502","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Article","associatedPublications":[],"authors":[{"id":619317258,"identity":"913afeeb-0914-4b9d-bc5a-8220f4ef45b2","order_by":0,"name":"Haozhi 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Using 2.1 million news articles across 184 countries and 40 languages, combined with AI-assisted geolocation and human-in-the-loop validation,\r\nwe expose global under-reporting of extreme heat events. We find that only a tiny fraction of identified extreme heat events enters widely used global disaster databases, while 63.38% remain unreported even across the most comprehensive global and local news coverage. Under-reporting is concentrated in places like equatorial Africa, the Amazon basin, small island states, such as the Caribbean, and polar adjacent regions, where limited early warning capacity, high vulnerability, and linguistic distance from dominant languages intersect. Under the high-emissions scenario SSP5-8.5, by 2050, the largest future heat burdens are concentrated in highly vulnerable countries that coincide with the most severe under-reporting of extreme heat. These countries are projected to incur economic losses 60.09% higher and mortality-related losses 46.40% higher than better-reported countries. Yet pervasive under-reporting suggests that even these severe loss projections remain conservative for regions with the highest vulnerability, reinforcing the urgency of loss-and-damage action.","manuscriptTitle":"Missed Reports of Extreme Heat Events Exacerbate Vulnerability and Losses","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2026-04-09 01:42:52","doi":"10.21203/rs.3.rs-9186502/v1","editorialEvents":[],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"nature-climate-change","isNatureJournal":true,"hasQc":false,"allowDirectSubmit":false,"externalIdentity":"nclimate","sideBox":"Learn more about [Nature Climate Change](http://www.nature.com/nclimate/)","snPcode":"","submissionUrl":"","title":"Nature Climate Change","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"ejp","reportingPortfolio":"Nature Research","inReviewEnabled":true,"inReviewRevisionsEnabled":false}}],"origin":"","ownerIdentity":"773da3be-644c-4c20-82a9-07680964853c","owner":[],"postedDate":"April 9th, 2026","published":true,"recentEditorialEvents":[{"type":"editorInvitedReview","content":"This content is not available.","date":"2026-05-06T10:31:31+00:00","index":1,"fulltext":"This content is not available."},{"type":"editorInvitedReview","content":"This content is not available.","date":"2026-05-04T12:39:30+00:00","index":2,"fulltext":"This content is not available."},{"type":"reviewerAgreed","content":"This content is not available.","date":"2026-05-04T07:49:46+00:00","index":2,"fulltext":"This content is not available."}],"rejectedJournal":[],"revision":"","amendment":"","status":"under-review","subjectAreas":[{"id":65900023,"name":"Scientific community and society/Social sciences/Climate change/Climate-change impacts/Governance"},{"id":65900024,"name":"Earth and environmental sciences/Climate sciences/Climate change/Climate-change impacts/Governance"},{"id":65900025,"name":"Scientific community and society/Developing world"},{"id":65900026,"name":"Scientific community and society/Social sciences/Communication"}],"tags":[],"updatedAt":"2026-04-09T01:42:52+00:00","versionOfRecord":[],"versionCreatedAt":"2026-04-09 01:42:52","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-9186502","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-9186502","identity":"rs-9186502","version":["v1"]},"buildId":"XKTyCvWXoU3ODBz1xrDgd","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}