A Greenhouse gas (sometimes abbreviated GHG) is a gas in the atmosphere that absorts and emits radiation within the thermal infrared range. This process is the fundamental cause of the greenhouse effect.
The primary greenhouse gases in the Earth’s atmosphere water vapour, carbon dioxide, methane, nitrous oxide and ozone.
In the solar system, the atmosphere of venus, Mars and Titan also contain gases that cause greenhouse effects.
Global warming is the increase of Earth’s average surface temperature due to effect of greenhouse gases, such as carbon dioxide emissions from burning fossil fuels or from deforestation. This is a type of greenhouse effect.