Greenhouse gases (GHG) trap heat in the atmosphere and help to maintain the Earth’s surface at a temperature that is comfortable for human life. The main GHG that exist in our atmosphere are carbon dioxide, methane, nitrous oxide and sulfur hexafluoride.
Although many GHG occur naturally, their concentration in the atmosphere has greatly increased due to human activity. This increase has been evident since the Industrial Revolution. The primary sources of greenhouse gas emissions are electricity production, transportation, industrial processes, agriculture and the use of natural gas and other fossil fuels for heat. When a fossil fuel undergoes combustion it releases GHG.
As levels of GHG in the atmosphere increase, the temperature on the Earth’s surface also increases. To limit the levels of GHG emitted into the atmosphere, it is important to keep track of total GHG released. The annual GHG emissions inventory is a starting point for measuring efforts to reduce GHG emissions.