Carbon dioxide (CO2) injection in deep geological formations induces coupled thermo-hydro-mechanical-chemical (THMC) processes that may compromise the safety of the storage. Proper characterization and management of CO2 storage sites should carefully consider the geomechanical response induced by pressure buildup and consequent changes in stress and strain states. On top of that, thermo-mechanical effects play the role because CO2 reaches the storage formation at a colder temperature than that corresponding to the geothermal gradient. Additionally, CO2 dissolves into in-situ brine, forming carbonic acid that leads to a reduction of the pH and dissolution/precipitation of minerals. These geochemical reactions may alter the geomechanical properties of rocks and faults in the long term. To improve the knowledge and minimize the uncertainty in the short- and long-term subsurface CO2 injection operations, the study of coupled thermo-hydro-mechanical-chemical (THMC) processes at multiple scales is required: from millimeter scale samples to cores tested in the laboratory, field-scale tests performed at pilot sites, and reservoir-scale related to industrial storage sites. This session is aimed at discussing CO2 storage related THMC coupling and upscaling of the coupled processes with the numerical models.