Carbon Dioxide (CO₂) is a natural by-product of fossil fuel combustion and the most important man-made greenhouse gas.

Not only does it account for 77% of global GHG emissions but all other man-made GHG emissions are
measured in the impact on global warming in terms of tons of CO₂ equivalent (tCO₂e).

The main sources of man-made CO₂ emissions are:

	Power Stations	30%
	Industrial Processes	21%
	Transportation Fuels	20%
	Residential/Commercial	13%
	Land Use	9%
	Fossil fuel retrieval, processing & distribution	8%