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
Supercritical carbon dioxide the supercritical state and injected into geological storage, possibly into existing oil fields to improve yields. The unique properties of s ensure that it remains out of the atmosphere. Supercritical could be used as a working fluid in enhanced geothermal systems. Possible advantages compared to water include higher energy yield resulting from its lower viscosity, better chemical interaction, storage through fluid loss and higher temperature limit. As of 2011, the concept had not been tested in the field. Supercritical carbon dioxide is used in the production of silica, carbon and metal based aerogels. For example, silicon dioxide gel is formed