Answer: 4. Infrared radiation
Explanation: Both carbon dioxide and methane are excellent absorbers of heat. The heat energy causes the molecule of carbon dioxide and methane to vibrate. As a result of this, the molecules gives up the extra energy by emitting infrared photon.
Therefore, the Evidence that supports the idea that increases in carbon dioxide and methane in Earth's atmosphere are major contributors to global warming is primarily based on the fact that carbon dioxide and methane are excellent absorbers of infrared radiation