ABSTRACT
Carbon cycles through reservoirs on the Earth’s surface in plants and soils exist in the atmosphere as gases, such as carbon dioxide (CO2) and methane (CH4), and in ocean water in phytoplankton and marine sediments. CO2 and CH4 are released into the atmosphere by the combustion of fossil fuels, land cover changes on the Earth’s surface, respiration of green plants, and decomposition of carbon in dead vegetation and in soils, including carbon in permafrost. Ÿe atmospheric concentrations of CO2 and CH4 control atmospheric and oceanic temperatures through their absorption of outgoing long-wave radiation and thus also indirectly control sea level via the regulation of planetary ice volumes.
