A marine vessel and method for carbon capture and sequestration are described. The marine vessel includes a buoyant hull, a cryogenic storage tank within the hull, and a gaseous carbon dioxide loading manifold. The marine vessel also includes a carbon dioxide liquefaction system in fluid communication with the cryogenic storage tank downstream of the carbon dioxide liquefaction system and with the gaseous carbon dioxide loading manifold upstream of the carbon dioxide liquefaction system. Finally, the marine vessel includes a carbon dioxide supercritical system in fluid communication with the cryogenic storage tank. In operation, the marine vessel moves between multiple locations, where gaseous carbon dioxide is onboarded, liquified and stored. Thereafter, the marine vessel transports the liquified carbon dioxide to a location adjacent an offshore geological reservoir. The liquefied carbon dioxide is then pressurized to produce supercritical carbon dioxide, which is then injected directly into the reservoir from the marine vessel.