Das Projekt "GOSAC: globale Speicherung anthropogenen Kohlenstoffs in den Ozeanen" wird vom Umweltbundesamt gefördert und von Universität Bern, Physikalisches Institut, Abteilung für Klima- und Umweltphysik durchgeführt. This study has three primary objectives: (1) to better quantify past, present, and future C02 uptake by the ocean, which is limited by relatively slow natural processes; (2) to evaluate global aspects of the proposal which offers to artificially accelerate ocean storage of C02 by diverting C02 emissions from fossil-fuel fired power plants directly into the abyss, thereby short-circuiting the natural process; and (3) to assess if predictions stemming from the first two objectives are reasonable, by paying close attention to model validation. Here, seven independantly developed 3-D ocean models from Europe jointly seek European Community support to participate in the Ocean Carbon-Cycle Model Intercomparison Project (OCMIP), an IGBP/GAIM initiative begun in 1995 to compare and validate ocean carbon-cycle models of the global ocean (Objective 1). Support is further sought to use these same models to assess one potential means to help mitigate increasing concentrations of atmospheric C02: deep-ocean C02 disposal (Objective 2). Model validation (Objective 3) is necessary to determine if any envelope of model predictions is likely to bracket real ocean behavior. The ocean is by far the largest reactive reservoir of carbon on earth. Most anthropogenic C02 will one day be stored there, despite relatively slow oceanic uptake which cannot keep pace with excess C02 emissions to the atmosphere. Ocean models provide the best means to assess past and present oceanic C02 uptake; they provide the only means to predict future changes. Comparison and validation of global ocean models is crucial to improving the large uncertainties associated with our understanding of the ocean's role in the global carbon cycle. Well validated ocean models offer our only tool to assess how ocean uptake will change due to future changes in ocean chemistry, biology, and circulation. This effort will assess how changes in ocean carbonate chemistry will effectively reduce oceanic uptake, and how differences in biology and circulation between some of the models may affect results. Ocean models have shown that certain strategies to artificially enhance ocean C02 uptake, such as iron fertilization, would be inefficient at sequestering additional C02; conversely, direct injection of excess C02 appears promising, but only one 3-D model has begun to assess its effectiveness. Prime Contractor: Centre National de la Recherche Scientifique, FU 0005 - Institut Pierre-Simon Laplace; Guyancourt/France.