Primary greenhouse gases and global warming. Molecular models over a burning marine landscape of the four primary greenhouse gases found in the Earth's atmosphere. These gases contribute to global warming and climate change. Across bottom, they are: nitrous oxide (N2O), methane (CH4), carbon dioxide (CO2) and water vapour (H2O). Atoms are represented as spheres and are colour-coded: carbon (black), nitrogen (blue), oxygen (red or pink) and hydrogen (green). The energy surfaces of the molecules are also shown.