Carbon dioxide in Earth's atmosphere atmosphere, oceans, soil, rocks, and volcanism. Both carbon cycles are intrinsically interconnected and atmospheric gaseous carbon dioxide facilitates the carbon cycle. Natural sources of atmospheric carbon dioxide include volcanic outgassing, the combustion of organic matter, wildfires and the respiration processes of living aerobic organisms. Man-made sources of carbon dioxide include the burning of fossil fuels for heating, power generation and transport, as well as some industrial processes such as cement making. It is also produced by various microorganisms from fermentation and cellular respiration. Plants, algae and cyanobacteria convert carbon dioxide to carbohydrates by a process called photosynthesis. They gain the
Carbon dioxide clathrate Celsius (bottom and top respectively). On the vertical ones are given the pressure (left) and the estimated depth in the Martian regolith (right). The horizontal dashed line at zero depth represents the average Martian surface conditions. The two bent dashed lines show two theoretical Martian geotherms after Stewart & Nimmo (2002) at 30° and 70° latitude. Carbon dioxide clathrate Carbon dioxide hydrate is a snow-like crystalline substance composed of water ice and carbon dioxide. It normally is a Type I gas clathrate. However, there has been some experimental evidence for the development of a metastable Type II phase at A