Carbon dioxide in Earth's atmosphere initial carbon dioxide in the atmosphere of the young Earth was produced by volcanic activity, modern volcanic activity releases only 130 to 230 megatonnes of carbon dioxide each year. These natural sources are nearly balanced by natural sinks, physical and biological processes which remove carbon dioxide from the atmosphere. For example, some is directly removed from the atmosphere by land plants for photosynthesis and it is soluble in water forming carbonic acid. There is a large natural flux of into and out of the biosphere and oceans. In the pre-industrial era these fluxes were largely in balance. Currently about 57%
Ocean storage of carbon dioxide injection, carbon dioxide hydrate is another popular method for storage. Hydrate formation takes place when the dissolved concentration of liquid carbon dioxide is around 30% and 400 meters below sea level. Hydrates form as an external layer around liquid carbon dioxide droplets or as a solid mass. The molecular composition is composed of carbon dioxide and water, carbon dioxide•nHO (n ≈ 5.75). The resulting density is denser than seawater by approximately 10%. Compared to liquid carbon dioxide, the hydrate form dissolves significantly slower in seawater, at about 0.2 cm/hr as well. Additionally, the hydrate remains immobile on the seafloor and