The world ocean is an integral part of the climate system: the coupling processes and feedback mechanisms among atmosphere, ocean, land surface, and cryosphere will determine the features and behavior of the climate system of the future.
Since the industrial revolution, the ocean has evolved into a major sink for carbon generated by human activities. Without oceanic and terrestrial sinks, atmospheric CO2 levels would be close to 600 ppm (parts per million), well above the level compatible with a global warming target limited to 2 ̊C.
In the context of climate change, however, it is still unclear to scientists if the ocean will continue to help mitigate the effects of global warming, or its capacity to absorb carbon from the atmosphere will be altered as a consequence of the numerous human-induced ocean changes.
The world ocean absorbs roughly 28% of the excess CO2 emissions thus acting as the equal second reservoir of anthropogenic CO2 together with terrestrial ecosystems. This comes with a price: the ocean has become significantly more acidic, which can affect the ability of marine organisms such as plankton, mollusks, and reef-building corals to build and maintain shells and skeletal material. The ocean has also warmed significantly in modern times, which has an impact on marine organisms and also on the distribution of oxygen and the emergence of "dead" (extremely poor in oxygen) zones. This more acidic, warmer, and poor in oxygen world ocean has clear effects in terms of reduced ecosystem functioning for ecosystem services such as climate mitigation and food security.
Our work on Climate
The Intergovernmental Oceanographic Commission of UNESCO is at the forefront of climate science and knowledge that inform and underpin meaningful actions to counteract climate change:
World Climate Research Programme
Integrated Ocean Carbon Research