Carbon Dioxide

Carbon dioxide (CO2) is a product of respiration of all aerobic organisms. It is returned to normal water via the gills of fish and to the air by means of the lungs associated with air-breathing land creatures, including humans. Carbon dioxide is produced in the processes of rot away of organic materials and also the fermentation of sugar in bread, light beer and winemaking. It is produced by combustion associated with wood, carbohydrates and fossil fuels such as coal, peat, petroleum and natural gas.