Sea level fall during glaciation stabilized atmospheric CO2 by enhanced volcanic degassing

Joerg Hasenclever, Gregor Knorr, Lars H. Ruepke, Peter Koehler, Jason Morgan, Kristin Garafolo, Stephen Barker, Gerrit Lohmann, Ian R. Hall

Research output: Contribution to journalArticlepeer-review


Paleo-climate records and geodynamic modelling indicate the existence of complex interactions between glacial sea level changes, volcanic degassing and atmospheric CO2, which may have modulated the climate system’s descent into the last ice age. Between B85 and 70 kyr ago, during an interval of decreasing axial tilt, the orbital component in global temperature records gradually declined, while atmospheric CO2, instead of continuing its long-term correlation with Antarctic temperature, remained relatively stable. Here, based on novel global geodynamic models and the joint interpretation of paleo-proxy data as well as biogeochemical simulations, we show that a sea level fall in this interval caused enhanced pressure-release melting in the uppermost mantle, which may have induced a surge in magma and CO2 fluxes from mid-ocean ridges and oceanic hotspot volcanoes. Our results reveal a hitherto unrecognized negative feedback between glaciation and atmospheric CO2 predominantly controlled by marine volcanism on multi-millennial timescales of B5,000–15,000 years.
Original languageEnglish
Article number15867
Pages (from-to)1-11
Number of pages11
JournalNature Communications
Publication statusPublished - 6 Jul 2017

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