1. Energy from the Sun

2. The sun’s energy interacts with Earth’s atmosphere and surface in several ways.

3. About 50 percent of the sun’s energy is absorbed by Earth’s surface
About 50 percent of the sun’s energy is absorbed by Earth’s surface. This energy heats the land and water.

4. Some absorbed energy is radiated back into the atmosphere

5. 5 percent of the sun’s energy is reflected by the surface back into the atmosphere.

6. 20 percent of the energy is absorbed by gases and particles in the atmosphere.

7. About 25 percent of the sun’s incoming sunlight is reflected by clouds, dust, and gases in the air.

8. Energy at Earth’s Surface

9. When Earth’s surface is heated,

10. It radiates most of the energy back into the atmosphere as infrared radiation.

11. Much of this infrared radiation cannot travel all the way through the atmosphere back into space. Instead, it is absorbed by water vapor, carbon dioxide, methane, and other gases in the air.

12. The energy from the absorbed radiation heats the gases in the air
The energy from the absorbed radiation heats the gases in the air. These gases form a “blanket” around Earth that holds heat in the atmosphere.
The “greenhouse effect” is a natural process that keeps Earth’s atmosphere at a temperature that is comfortable for most living things. However, emissions from human activates may be altering this process.