Greenhouse gases such as carbon dioxide are released during the burning of fossil fuels, particularly during energy production, and are acknowledged internationally as being major contributors to global warming. Once released, these are trapped in the Earth’s atmosphere where they absorb the sun's energy and cause the earth to warm at a faster rate than usual. The name comes from the phenomena of glass trapping heat in a greenhouse.
Six greenhouse gases are regulated under the Kyoto Protocol, which 163 nations signed in 1997 agreeing to limit and reduce the levels of greenhouse gas emissions. The principle gases are carbon dioxide (CO2), methane (CH4) and nitrous oxide (N2O).