4. Energy enters the Earth system primarily as solar radiation and

eventually escapes as heat. As a basis for understanding this concept:

a. Students know the relative amount of incoming solar energy compared with

Earth’s internal energy and the energy used by society.

b. Students know the fate of incoming solar radiation in terms of reflection,

absorption, and photosynthesis.

c. Students know the different atmospheric gases that absorb the Earth’s

thermal radiation and the mechanism and significance of the greenhouse

effect.