But between us and this incoming energy is the earth's atmosphere where absorption and scattering produce important changes in its composition and strength.

sphere would rise by 6 °c in a year. This is why the rise in the carbon dioxide level is watched with such interest. This rise is due to the burning of fossil fuel and forests. The carbon dioxide in the atmosphere absorbs some of the infrared energy radiated from the earth so that a rise in carbon dioxide level will result in a rise in temperature.