Abstract The dissolution of CO2 from a CO2 lake with and without a hydrate layer, located at a flat bottom at 3000 m depth has been modeled using the MIT General Circulation Model coupled with the General Ocean Turbulence Model (GOTM). The vertical turbulent mixing scheme takes into account density effects and should give more realistic results for the CO2 plume than previously used constant eddy diffusivity models. The introduction of a third direction gives qualitatively different results for the spreading of the CO2 plume than previous 2D results. The dissolution rate and near field dissolved CO2 concentrations approach a steady state for a given far field ocean current within less than a day. The dissolution rate is highly dependent on the velocity of the ambient current and is reduced with 1.6 when a hydrate layer is introduced.