Carbon Dioxide

( Article Type: Explanation )

Carbon dioxide is a gas that occurs naturally in the air and is produced when animals breathe, vegetation rots and when material containing carbon is burnt or broken down. Carbon dioxide is a key component in photosynthesis, which is the major base source of food for organisms on earth. In photosynthesis, carbon dioxide combines with water and sunlight (energy) to produce sugars which, in turn, provide energy for plants from which they live and grow.

Millions of years ago, the Earth’s atmosphere consisted mainly of carbon dioxide until plants gradually removed the gas and, through decomposition, ‘fixed’ the carbon in the fossil fuels, coal, oil and gas. Humankind is now reversing that process by releasing the carbon again through excessive burning of fossil fuels.

Carbon dioxide is one of the so-called ‘greenhouse gases’ that absorb heat in the atmosphere. The release of carbon dioxide through excessive burning of fossil fuels adds to global warming. The carbon dioxide is absorbed back into the system physically through plants and trees but this can be arrested if humankind cuts down too many trees and reduces that absorption capacity.