CARBOCHANGE, i.e., Changes in carbon uptake and emissions by oceans in a changing climate, is a large-scale integrating collaborative research project funded by the EU 7th Framework Program from 2011to 2015.

It is coordinated by the Geophysical Institute and the Bjerknes Centre for Climate Research, Bergen, Norway. The CARBOCHANGE consortium consists of 28 research institutions from Europe, North America and Africa with key scientific experts in the field.

CARBOCHANGE will provide the best possible process-based quantification of net ocean carbon uptake under changing climate conditions using past and present ocean carbon cycle changes for a better prediction of future ocean carbon uptake. CARBOCHANGE will combine observational efforts with model simulations and:

• improve the quantitative understanding of key biogeochemical and physical processes through a combination of observations and models,

• upscale new process understanding to large-scale integrative feedbacks of the ocean carbon cycle to climate change and rising carbon dioxide concentrations,

• quantify the vulnerability of the ocean carbon sources and sinks in a probabilistic sense using cutting edge coupled Earth system models under a spectrum of emission scenarios including climate stabilisation scenarios as required for the 5th IPCC assessment report.

The drivers for the vulnerabilities will be identified. The most actual observations of the changing ocean carbon sink will be systematically integrated with the newest ocean carbon models, a coupled land-ocean model, an Earth system model of intermediate complexity, and fully-fledged Earth system models through a spectrum of data assimilation methods as well as advanced performance assessment tools.

Results will be optimal process descriptions and most realistic error margins for future ocean carbon uptake quantifications with models under the presently available observational evidence. The project will deliver calibrated future evolutions of ocean pH and carbonate saturation as required by the research community on ocean acidification in the EU project EPOCA and further projects in this field. The time history of atmosphere-ocean carbon fluxes past, present and future will be synthesized globally as well as regionally for the transcontinental RECCAP project.

Our work for CARBOCHANGE here at AWI is conducted in the Southern Ocean where we use repeated transects of FS Polarstern with measurements of the CO2 system, oxygen, nutrients and other parameters (provided by our partners) to enable a decadal picture to be built up in the Atlantic sector. We will collect and publish highest quality carbon system data on the interior ocean. We will produce an analysis of trends in anthropogenic carbon storage and its vulnerability to climate change.

CARBOCHANGE strongly builds on the results of the previous EU 6th Framework Program Integrated Project CARBOOCEAN.