#152 Greenhouse gases and global warming

Some gases in the Earth’s atmosphere stop heat radiating into space from the Earth. This is called the greenhouse effect and the gases involved are called greenhouse gases. They include:methane, CO₂ and water vapour. An increased greenhouse effect can lead to global warming and climate change.

The diagram shows how the greenhouse effect works.

1. Electromagnetic radiation at most wavelengths from the Sun passes through the Earth’s atmosphere.

2. The Earth absorbs electromagnetic radiation with short wavelengths and so warms up. Heat is radiated from the Earth as longer wavelength infrared radiation.

3.Some of this infrared radiation is absorbed by greenhouse gases in the atmosphere.

4. The atmosphere warms up.

Source: BBC Bytesize