1. Earth’s Energy Budget

3. Earth’s Energy Source The Sun is the source of Earth’s energy
Most of the Sun’s energy is in the form of visible light

4. Earth’s energy balance
Just like a family’s financial budget, a stable energy budget must be balanced:
Energy In = Energy Out
The energy coming in from the Sun should equal the energy leaving Earth (going back out into space)

5. Incoming Sunlight About 30% is reflected directly back to space
this % is called albedo
Some is reflected by clouds and the atmosphere
A little is reflected from Earth’s surface
e.g., bright snow-covered areas
About 70% is absorbed by
Earth and heats it up

6. Radiated energy
Most incoming sunlight is radiated back out as heat to space
Radiation means releasing heat in waves or particles
Some heat is trapped by water and other gases in the atmosphere and is sent back to the surface
This is the greenhouse effect

7. The greenhouse effect

9. Write your summary
A few sentences that sum up the day’s lecture.