A greenhouse gas is any gaseous compound in the atmosphere that is capable of absorbing infrared radiation, thereby trapping and holding heat in the atmosphere. By increasing the heat in the atmosphere, greenhouse gases are responsible for the greenhouse effect, which ultimately leads to global warming.
Many of these gases occur naturally, but human activity is increasing the concentrations of some of them in the atmosphere, in particular:
- carbon dioxide (CO2)
- methane
- nitrous oxide
- fluorinated gases