Aerosolized Calcium Hydroxide for Climate Mitigation:Conceptual Feasibility and Governance Challenges

Aerosolized Calcium Hydroxide for Climate Mitigation:Conceptual Feasibility and Governance Challenges | 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 Research Article Aerosolized Calcium Hydroxide for Climate Mitigation:Conceptual Feasibility and Governance Challenges Saurabhya Puri This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-7782517/v1 This work is licensed under a CC BY 4.0 License Status: Posted Version 1 posted You are reading this latest preprint version Abstract Atmospheric carbon dioxide (CO$_2$) concentrations are on the rise, increasing global warming and environmental risks. To protect our environment, carbon dioxide removal (CDR) technologies are increasingly recognized as essential instruments to rapid de-carbonization. This paper explores the conceptual possibility of aerosolized calcium hydroxide [Ca(OH)$_2$] dispersal as a CO$_2$ removal technique. The underlying chemistry is simple: CO$_2$ reacts with Ca(OH)$_2$ to form stable calcium carbonate (CaCO$_3$). Stoichiometric calculations shows that 1,kg of Ca(OH)$_2$ can bind 0.594,kg of CO$_2$, so removing 1,Gt CO$_2$ would require approximately 1.7,Gt of Ca(OH)$_2$. The materials required are comparable to global cement production, so scaling, while challenging, is not impossible. This paper assess key factors influencing feasibility, including atmospheric residence times, life cycle carbon balance, ecological deposition impacts, and governance challenges. While carbonation offers a permanent sink, achieving net-negative outcomes depends on decarbonized Ca(OH)$_2$ production and management of side effects, particularly in soil and marine ecosystems is necessary. Even partial deployment at a gigatonne scale represents a meaningful contribution, comparable to the annual emissions of a major industrialized nation. This paper positions aerosolized Ca(OH)$_2$ not as a deployable solution, but as a research direction which requires systematic study, testing, and integration into broader environmental management and CDR strategies. Carbon dioxide removal Calcium hydroxide aerosols Atmospheric carbonation Climate change mitigation Environmental governance Negative emissions technologies Full Text Additional Declarations No competing interests reported. Cite Share Download PDF Status: Posted 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-7782517","acceptedTermsAndConditions":true,"allowDirectSubmit":true,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":525345371,"identity":"35744314-16e0-4fae-971b-f44d7a23b0e1","order_by":0,"name":"Saurabhya Puri","email":"data:image/png;base64,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","orcid":"","institution":"","correspondingAuthor":true,"prefix":"","firstName":"Saurabhya","middleName":"","lastName":"Puri","suffix":""}],"badges":[],"createdAt":"2025-10-05 03:23:06","currentVersionCode":1,"declarations":{"humanSubjects":false,"vertebrateSubjects":false,"conflictsOfInterestStatement":false,"humanSubjectEthicalGuidelines":false,"humanSubjectConsent":false,"humanSubjectClinicalTrial":false,"humanSubjectCaseReport":false,"vertebrateSubjectEthicalGuidelines":false},"doi":"10.21203/rs.3.rs-7782517/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-7782517/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":92943943,"identity":"a5c70756-c04b-456c-9f45-a66fdb3e150c","added_by":"auto","created_at":"2025-10-07 12:02:01","extension":"json","order_by":0,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":3471,"visible":true,"origin":"","legend":"","description":"","filename":"1d738dc182be4384870b6240621031d9.json","url":"https://assets-eu.researchsquare.com/files/rs-7782517/v1/241d08d06fdded5977d31ee4.json"},{"id":94988129,"identity":"853025c2-0bf7-4a8b-95d6-6cb72a602a85","added_by":"auto","created_at":"2025-11-03 07:05:03","extension":"pdf","order_by":1,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":226722,"visible":true,"origin":"","legend":"","description":"","filename":"AerosolizedCalciumHydroxideforClimateMitigationConceptualFeasibilityandGovernanceChallenges.pdf","url":"https://assets-eu.researchsquare.com/files/rs-7782517/v1_covered_faf49573-d2e9-447e-8c3c-3a620ea6f5b6.pdf"}],"financialInterests":"No competing interests reported.","formattedTitle":"Aerosolized Calcium Hydroxide for Climate Mitigation:Conceptual Feasibility and Governance Challenges","fulltext":[],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":false,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":true,"hideJournal":true,"highlight":"","institution":"","isAcceptedByJournal":false,"isAuthorSuppliedPdf":true,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":true,"isPdf":true,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true},"keywords":"Carbon dioxide removal, Calcium hydroxide aerosols, Atmospheric carbonation, Climate change mitigation, Environmental governance, Negative emissions technologies","lastPublishedDoi":"10.21203/rs.3.rs-7782517/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-7782517/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":" Atmospheric carbon dioxide (CO$_2$) concentrations are on the rise, increasing global warming and environmental risks. To protect our environment, carbon dioxide removal (CDR) technologies are increasingly recognized as essential instruments to rapid de-carbonization. This paper explores the conceptual possibility of aerosolized calcium hydroxide [Ca(OH)$_2$] dispersal as a CO$_2$ removal technique. The underlying chemistry is simple: CO$_2$ reacts with Ca(OH)$_2$ to form stable calcium carbonate (CaCO$_3$). Stoichiometric calculations shows that 1\\,kg of Ca(OH)$_2$ can bind 0.594\\,kg of CO$_2$, so removing 1\\,Gt CO$_2$ would require approximately 1.7\\,Gt of Ca(OH)$_2$. The materials required are comparable to global cement production, so scaling, while challenging, is not impossible. This paper assess key factors influencing feasibility, including atmospheric residence times, life cycle carbon balance, ecological deposition impacts, and governance challenges. While carbonation offers a permanent sink, achieving net-negative outcomes depends on decarbonized Ca(OH)$_2$ production and management of side effects, particularly in soil and marine ecosystems is necessary. Even partial deployment at a gigatonne scale represents a meaningful contribution, comparable to the annual emissions of a major industrialized nation. 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