Reconstructed late-Pleistocene CO2 fluxes reveal a shift in carbon cycling since the Mid-Brunhes transition

Reconstructed late-Pleistocene CO2 fluxes reveal a shift in carbon cycling since the Mid-Brunhes transition | 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 Reconstructed late-Pleistocene CO 2 fluxes reveal a shift in carbon cycling since the Mid-Brunhes transition Luca Castrogiovanni, Pietro Sternai, Claudia Pasquero, Nicola Piana Agostinetti, and 1 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-7646995/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 Ice cores provide constraints on past carbon cycling and associated atmospheric CO2 and mean surface temperature variations1,2, revealing systematic shifts between glacial and interglacial climate states3,4. However, poor quantification of surface source and sink CO2 fluxes hinders understanding of the drivers and feedbacks behind such climate variability. Correlated atmospheric CO₂ and temperature variations over the past ~800 kyr are largely due to orbital forcing, but the intensification of glacial-interglacial cycles since ~430 ka, following the so-called Mid-Brunhes Transition (MBT)5, cannot be explained by orbital parameters alone6. This suggests the activation of interacting mechanisms within the Earth system, the nature of which remains debated. We apply a new Bayesian inversion algorithm7 to the Dome C (Antarctica) CO₂ and temperature record3,4 to generate unprecedented reconstructions of surface CO₂ source and sink fluxes. Results reveal systematic pulses of CO₂ source fluxes during glacial maxima and deglaciations, preceding peaks in CO₂ sink fluxes, with all pulses first appearing post-MBT. Wavelet coherence and cross-correlation analyses suggest that post-MBT climate variability was amplified by feedbacks linking sea-level change, ice-sheet dynamics, and volcanic CO₂ emissions8,9. Our findings underscore the influence of the solid Earth on late-Pleistocene carbon cycling and climate and offer critical constraints for models of past and future climates. Earth and environmental sciences/Climate sciences/Palaeoclimate Earth and environmental sciences/Solid Earth sciences/Volcanology Earth and environmental sciences/Climate sciences/Climate change/Climate and Earth system modelling carbon cycle glacial-interglacial cycles CO2 fluxes sea-level change volcanism Full Text Additional Declarations There is NO Competing Interest. Supplementary Files ExtendedData.pdf Reconstructed late-Pleistocene CO2 fluxes reveal a shift in carbon cycling since the Mid-Brunhes transition 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-7646995","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Article","associatedPublications":[],"authors":[{"id":532428192,"identity":"c52e9ebc-3633-478d-9c8c-167405881a53","order_by":0,"name":"Luca 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Wavelet coherence and cross-correlation analyses suggest that post-MBT climate variability was amplified by feedbacks linking sea-level change, ice-sheet dynamics, and volcanic CO₂ emissions8,9. 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