Earth and Radiation

• The Sun is close by (well, about 150 million km away) and transfers energy to us by EM radiation
• A lot of the Sun's energy is reflected or emitted back into space
• Radiation Affects the Earth's Temperature


  1. During the day, lots of radiation (like light) is transferred to the Earth from the Sun and absorbed, causing an increase in local temperature

  2. At night, less radiation is being absorbed than is being emitted, causing a decrease in the local temperature

  3. Overall, the temperature of the Earth stays fairly constant
• You can show the flow of radiation for the Earth on a handy diagram
• What happens to the Sun's radiation

  • Some is reflected by the atmosphere, clouds and the Earth's surface
  • Some is absorbed by the atmosphere, clouds and the Earth's surface
  • Some is emitted by the atmosphere
  • Some of the radiation emitted by the surface is reflected or absorbed (and later emitted) by the clouds
• Changes to the atmosphere


  Can cause a change to the Earth's overall temperature
• If the atmosphere starts to absorb more radiation without emitting the same amount

  The overall temperature will rise until absorption and emission are equal again