Greenhouse gases are gases in the atmosphere that trap heat radiation from the earth and thus contribute to the greenhouse effect. The main greenhouse gases are carbon dioxide (CO2), methane (CH4), nitrous oxide (N2O) and hydrofluorocarbons (HFCs). Human activities such as the burning of fossil fuels, agriculture and waste disposal increase the concentration of these gases in the atmosphere, which leads to an increase in the global average temperature and thus to global warming.
