Key learning points

1. Carbon dioxide and methane are common greenhouse gases.
2. Greenhouse gases reduce the amount of lower-energy IR that can escape from Earth’s atmosphere.
3. Greenhouse gases do not reduce the amount of higher-energy IR radiation entering the atmosphere from the Sun.
4. If the rate energy is transferred into the atmosphere exceeds the rate it is transferred out, average temperatures rise.
5. An increasing average temperature of Earth’s atmosphere is called global warming.

Keywords

• Greenhouse gas - a gas that contributes to global warming by reducing the amount of radiation leaving Earth’s atmosphere

• Infrared (IR) radiation - a type of electromagnetic radiation that we can feel as warmth on our skin

• Carbon sink - a process or system that takes more carbon from the atmosphere than it releases

• Global warming - increase in Earth’s global temperature, likely caused by more greenhouse gases in the atmosphere

Common misconception