Key learning points

1. Carbon dioxide and methane are common greenhouse gasses.
2. Greenhouse gases reduce the amount of lower frequency IR that can escape from Earth’s atmosphere.
3. Greenhouse gases do not reduce the amount of higher frequency 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 - Greenhouse gases are gases that are responsible for the greenhouse effect by absorbing lower frequency IR radiation and trapping ‘heat’ in the atmosphere.

• Infrared radiation - Infrared radiation is a type of electromagnetic radiation that we can feel as heat.

• Frequency - Frequency is the number of waves that pass a point per second.

• Global warming - Global warming is the increase in Earth's average temperature, likely to be caused by increased amounts of atmospheric carbon dioxide.

Common misconception