Greenhouse Gases

Greenhouse gases essentially form a blanket over the earth’s atmosphere, trapping the sun’s heat near the earth’s surface. Without greenhouse gases, the sun’s heat would escape and temperatures on earth would be too cold to support life as we know it. However, human activities have significantly increased the concentrations of greenhouse gases in the atmosphere, causing it to retain more heat than it would otherwise retain naturally.

Greenhouse Gases of Concern
Greenhouse gases include water vapour (H2O), carbon dioxide (CO2), methane (CH4), nitrous oxide (N2O), ozone (O3), and halocarbons (eg. chlorofluorocarbons – CFCs, hydrofluorocarbons – HFCs).

Carbon dioxide (CO2) is a main greenhouse gas of concern because of the large quantities that are released through the burning of fossil fuels. It is estimated that the global consumption of fossil fuels produces 22,000,000,000 tonnes of CO2 every year with amounts projected to continue to increase. With 21 times the heat trapping effect of CO2, methane, nitrous oxide (N20) occurs naturally but increasing levels as a result of human activity are a source of concern.

© 2012, City of Richmond