CARBOOCEAN, Marine carbon sources and sinks assessment, will create scientific knowledge, which is essential to a quantitative risk/uncertainty judgement on the expected consequences of rising atmospheric CO2 concentrations. Based on this judgement, it will be possible to guide the development of appropriate mitigation actions, such as management of CO2 emission reductions within a global context (e.g. Kyoto Protocol, United Nations, 1997). CARBOOCEAN, is coordinated by the Bjerknes Centre for Climate Research at the University of Bergen. The project receives 14.5 million EURO (116 million NOK) support from the European Commission for the coming 5 years. Carbon dioxide from fossil fuel burning and land use changes is the largest contributor to a man-made forcing of climate change. The ocean is considered as the major ultimate sink for the atmospheric greenhouse gas carbon dioxide. The timing of the oceanic carbon dioxide uptake is one of the most critical factors in determining the strength of the expected climate change during the coming decades and centuries. The uptake of carbon dioxide by the ocean will be critical for how climate change will affect our future, and if we know this better, major improvements of our ability to predict future climate change will be possible. An accurate knowledge of the rate of carbon dioxide uptake is essential for human societies in order to plan ahead and to provide the best measures for minimizing the threat associated with a climate change. Reduction in emissions will be the most powerful mitigation action, as the dissociation of carbon dioxide in the ocean results in large scale acidification of the seawater with potentially negative consequences for ecosystems and fish stocks. As Norway plays a pivotal role in fisheries and oil production, the basic science research of CARBOOCEAN is carried out in front of a concrete socio-economic background. The coordination of this research project by the Bjerknes Centre at the University of Bergen underlines the expertise and leadership of this centre within the climate research communities, both nationally and worldwide. The Bjerknes Centre is a joint venture between the University of Bergen, the Nansen Environmental and Remote Sensing Center, and the Institute of Marine Research. The Bjerknes Centre is one of Norway´s designated Scientific Centres of Excellence.