Carbon capture and storage (CCS) refers to the process by which from large sources like power plants, CO2 is captured, compressed and transported to and injected into geological storage sites, which are generally deep underground layers of porous rock capped with impermeable rock, in ways that ensure the CO2 does not leak out into the atmosphere. The geological storage of carbon dioxide (CO2) can prevent and minimise the harmful effects of climate change. This directive establishes rules to ensure this practice is done safely.