The Quaternary period is defined by a succession of glacial-interglacial cycles, characterized by high-amplitude temperature and sea-level variations that provide critical insights into future climate change. Rapid climate shifts, mediated by the coupled atmosphere-ocean system, were super-imposed on gradual cyclic orbital change, and often accompanied by profound reorganizations of global carbon reservoirs. It is speculated that the abruptness of these climate shifts stemmed from a non-linear behaviour of the thermohaline circulation in response to waxing and waning of Arctic Ice Sheets and Antarctic sea-ice. However, pressing questions remain regarding the timing and pattern of change across glacial terminations and inceptions, as well as precise trigger mechanisms for carbon cycle perturbations.

This session hosts contributions from both proxy- and numerical-based approaches studying the climate dynamics of glacial-interglacial transitions, and climate-carbon cycle interactions focusing on both inceptions and terminations, with particular emphasis on the last deglaciation. With this session, we would like to i) advance the debate on the timing, drivers and pattern of glacial and deglacial climate change, and ii) deepen the debate concerning the mechanisms responsible for atmospheric pCO2 variability. We provide a platform for contributions addressing the full spectrum of spatio-temporal scales and those tackling widely studied carbon cycle dynamics such as changes in ocean circulation, ‘iron fertilization’, sea-level changes, ocean carbonate chemistry, and continental weathering. Nonetheless, we particularly highlight studies that constrain regional climate heterogeneities and less explored but potentially relevant carbon cycle processes such as terrestrial ecosystem feedbacks (e.g. vegetation and wetlands), permafrost dynamics, volcanic/metamorphic degassing, and hydrothermal venting