CO₂ is considered as the most important greenhouse gas and reduction of its amount in the atmosphere has been highly focused currently. One of the possibilities of effective reducing its emissions is capturing the carbon dioxide emitted into the atmosphere and its deposition within suitable disposal sites, namely in geosphere and material disposal sites. In this connection, the mechanism of CO₂ storage within these sites and related data on its sorption behavior in the region of sub- and supercritical temperatures is a research subject simultaneously. The proposed project has been aimed at the application of high-pressure sorption of CO₂ on selected carbonaceous materials in the pressure range up to 12 MPa using the volumetric method in dependence on temperature in the region of both sub- and supercritical temperatures, and on water content. The effect of the observed parameters on the sorption capacity and the proportion of adsorption and absorption, kinetics of the sorption processes, CO₂ diffusivity will be investigated, and deviation from Langmuir behavior will be interpreted.