Greenhouse gas footprint when they breathe and plants use it for photosynthesis. Carbon dioxide is released naturally by decomposition, ocean release and respiration. Humans contribute an increase of carbon dioxide emissions by burning fossil fuels, deforestation, and cement production. Methane (CH) is largely released by coal, oil, and natural gas industries. Although methane is not mass produced like carbon dioxide, it is still very prevalent. Methane is more harmful than carbon dioxide because it traps heat better than CO. Methane is a main component in natural gas. Recently industries as well as consumers have been using natural gas because they believe that it
Supercritical carbon dioxide heat pumps are commercially marketed in Asia. EcoCute systems from Japan, developed by Mayekawa, develop high temperature domestic water with small inputs of electric power by moving heat into the system from the surroundings. Supercritical has been used since the 1980s to enhance recovery in mature oil fields. "Clean coal" technologies are emerging that could combine such enhanced recovery methods with carbon sequestration. Using gasifiers instead of conventional furnaces, coal and water is reduced to hydrogen gas, carbon dioxide and ash. This hydrogen gas can be used to produce electrical power In combined cycle gas turbines, is captured, compressed to