Sub-seabed disposal is the safest disposal option for CO2. Water pressure and dilution into oceanic water prevent direct emission of CO2 into the air. Sediments under the deep sea floor are usually cool because the deep oceanic water is very cool. CO2 hydrate forms in the sediments in areas of the sea floor deeper than 300 m. The formation of CO2 hydrate in sediment pores almost completely prevents the escape of CO2.