Greenhouse Gases (AQA GCSE Combined Science: Trilogy): Revision Note

The greenhouse effect

• Greenhouse gases maintain the temperatures on Earth high enough to support life 

• This is known as the greenhouse effect 

• Three greenhouse gases are:

  • carbon dioxide

  • methane

  • water vapour 

What is the greenhouse effect?

• Short wavelength radiation (ultraviolet radiation) is emitted from the sun

• When it strikes the earth's surface, some of it is absorbed and some is re-emitted from the surface of the Earth as long wavelength radiation (infrared radiation)

• Much of the radiation is trapped inside the Earth’s atmosphere by greenhouse gases which can absorb and store the energy

• Increasing levels of carbon dioxide and methane, although present in only small amounts, are causing significant upset to the Earth’s natural conditions by trapping extra heat energy

The greenhouse effect 

Greenhouse gases trap some of the Sun's radiation causing the Earth to warm up