Quaternary climate variability is characterized by changes in atmospheric CO2 concentration (pCO2) from orbital (glacial-interglacial cycle) to centennial timescales. Studying this natural variability is essential to address the current challenges of climate change. However, interpreting these changes in pCO2 remains difficult due to the complex and poorly understood interactions between the different reservoirs of the climate system (ocean, atmosphere, biosphere, lithosphere, cryosphere) and their impacts on the carbon cycle. This session focuses on Quaternary climate changes and their interactions with the carbon cycle on various temporal scales (from orbital to centennial). Special attention will be given to contributions that explore variations in carbon stocks of the different reservoirs and carbon stocks vs. fluxes between these reservoirs using different approaches such as climate modelling, field studies and multi-tracer analyses (e.g. micropaleontology, geochemistry) of marine and terrestrial sediment cores and ice archives.