The oceans contain around 60 times more carbon than the atmosphere, mainly in the form of dissolved bicarbonate ions, as well as a large quantity of organic matter synthesized and recycled by a multitude of living organisms making up the marine biosphere. Since the beginning of the industrial era, the ocean has absorbed more than a third of the carbon dioxide emitted by mankind. Oceanic pumping is essentially due to the physico-chemical diffusion of excess CO2 to its acid-base hydrolysis and transport at depth by ocean circulation. The efficiency of the oceanic pump should evolve in the future in response to climate and related biogeochemical changes. At the same time, the invasion ofanthropogenic CO2 into the ocean is accompanied by acidification of seawater, which also affects biological organisms. The symposium will provide an update on the innovative aspects of this field of research, with a view to gaining a better understanding of current and future challenges.
