http://maps.grida.no/go/graphic/examples-of-ghg-emission-amounts-10



involves capturing CO2 emissions and storing them in geological formations that originally contained fossil fuels. CO2 emissions, for example from fossil fuel combustion, are captured and deposited beneath the Earth’s surface in depleted oil and gas wells, deep coal seams or aquifers (subterranean zones of water-bearing rock or sand). There are three basic technologies: absorption (take-up of a gas into the interior of a solid or liquid), adsorption (the gas is taken up in the form of a layer on the surface of a solid), and gas separation membranes.

Ocean sequestration beneath the surface
The ocean can hold enormous quantities of CO2 because unlike most atmospheric gases it reacts with water to form carbonate and bicarbonate greatly enhancing its solubility. It is estimated to hold about 38000 Gigatonnes of dissolved inorganic carbon (DIC). In comparison, the world’s total fossil carbon reserves, including conventional and unconventional deposits of oil, natural gas and coal, are estimated at about 6500 Gigatonnes of Carbon (GtC), so if all of them were burned and the CO2 sequestrated in the deep ocean, the DIC content would only increase about 17 per cent to 44500 GtC.