Carbon dioxide in Earth's atmosphere Atmospheric O levels are decreasing in Earth's atmosphere as it reacts with the carbon in fossil fuels to form . Burning fossil fuels such as coal, petroleum, and natural gas is the leading cause of increased anthropogenic ; deforestation is the second major cause. In 2010, 9.14 gigatonnes of carbon (GtC, equivalent to 33.5 gigatonnes of or about 4.3 ppm in Earth's atmosphere) were released from fossil fuels and cement production worldwide, compared to 6.15 GtC in 1990. In addition, land use change contributed 0.87 GtC in 2010, compared to 1.45 GtC in 1990. In 1997, human-caused Indonesian peat fires
Ocean storage of carbon dioxide IEA Greenhouse Gas R&D Programme estimates that dilute carbon dioxide injection would cost $70 per tonne of carbon dioxide including costs of carbon capture, transport, and storage before boat dispersal. Carbon dioxide ocean storage can occur through solid or solid hydrate of carbon dioxide. The solid state density of carbon dioxide is approximately 1.5 times greater than seawater and thus tends to sink to the ocean floor. The dissolving rate at the surface is about 0.2 cm/hr such that a small quantity of carbon dioxide can be completely dissolved before reaching the sea floor. In addition to solid carbon dioxide