4.15 understand how an increase in greenhouse gases results in an enhanced greenhouse effect and that this may lead to global warming and its consequences

Greenhouse gases: gases responsible for global warming. Includes carbon dioxide, nitrous oxide, methane, and CFC.

Enhanced greenhouse effect: impact on the climate from the additional heat retained due to the increased amounts of greenhouse gases that humans have released into the earth's atmosphere.

1. Sun emits ultraviolet radiation which is absorbed and re-emitted as infrared radiation by the Earth's surface
2. Greenhouse gases in the atmosphere absorb and re-radiates the infrared radiation
3. As a result, this heat is kept in the atmosphere which enhances the greenhouse effect.