Timescale competition controls tipping behaviour under climate overshoot

Timescale competition controls tipping behaviour under climate overshoot | 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 Physical Sciences - Article Timescale competition controls tipping behaviour under climate overshoot Lars Ackermann, Matteo Willeit, Gregor Knorr, Yuchen Sun, Uta Krebs-Kanzow, and 2 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-8941071/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 Tipping elements of the Earth system are often framed as threshold phenomena governed by peak global warming. However, climate components operate on widely differing intrinsic timescales, so the outcome of overshoot warming may depend not only on temperature thresholds but also on the interaction between forcing duration and system inertia. Here we use a comprehensive Earth system model with interactive ocean circulation, Arctic sea ice and a fully coupled Greenland Ice Sheet to simulate multi-millennial trajectories under extended overshoot scenarios. We find that reversibility is strongly component-specific. Fast components, including the Atlantic Meridional Overturning Circulation (AMOC) and Arctic sea ice, weaken during peak forcing but recover as greenhouse-gas concentrations decline. In contrast, the Greenland Ice Sheet shows persistent mass loss and long-term commitment even under strong mitigation, consistent with its slow dynamical adjustment and geometry-dependent feedback. Despite freshwater fluxes exceeding 0.1~Sv, AMOC collapse does not occur, highlighting the importance of spatial meltwater routing and advective export. Our results demonstrate that Earth system reversibility cannot be inferred from peak warming alone. Instead, overshoot duration reorganizes the hierarchy of tipping elements according to intrinsic process timescales. Tipping is therefore a dynamical outcome emerging from timescale competition within a coupled system. These findings imply that even temporary overshoot can irreversibly commit slow structural components of the climate system, redefining how climate stabilization targets should be interpreted on millennial timescales. Earth and environmental sciences/Climate sciences/Climate change/Climate and Earth system modelling Earth and environmental sciences/Ocean sciences/Physical oceanography Earth and environmental sciences/Planetary science/Cryospheric science Earth System Resilience Greenland Ice Sheet Atlantic Overturning Circulation Future Warming Scenarios Full Text Additional Declarations There is NO Competing Interest. 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. 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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-8941071","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Physical Sciences - Article","associatedPublications":[],"authors":[{"id":595629829,"identity":"d7baab56-2689-498a-baae-b4ca60a97923","order_by":0,"name":"Lars 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However, climate components operate on widely differing intrinsic timescales, so the outcome of overshoot warming may depend not only on temperature thresholds but also on the interaction between forcing duration and system inertia.\r\nHere we use a comprehensive Earth system model with interactive ocean circulation, Arctic sea ice and a fully coupled Greenland Ice Sheet to simulate multi-millennial trajectories under extended overshoot scenarios. We find that reversibility is strongly component-specific. Fast components, including the Atlantic Meridional Overturning Circulation (AMOC) and Arctic sea ice, weaken during peak forcing but recover as greenhouse-gas concentrations decline. In contrast, the Greenland Ice Sheet shows persistent mass loss and long-term commitment even under strong mitigation, consistent with its slow dynamical adjustment and geometry-dependent feedback. 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