Earth's Energy

Which of the following statements about Earth’s energy budget are true?

• Most energy reaches Earth from space as visible light.

• More than 99% of Earth’s outgoing energy comes from energy brought to Earth’s surface in volcanic eruptions.

• Energy leaves Earth’s system only during the daytime.

• Most of the energy that leaves Earth travels in the form of visible light.

from Earth’s surface directly to space

• radiation

• convection

• conduction

through the lithosphere to the surface

• conduction

• radiation

• convection

within the mantle, below the lithosphere

• radiation

• conduction

• convection

within the outer core

• convection

• conduction

• radiation

from the inner core to outer core

• radiation

• conduction

• evaluation

Over the past 150 years, the concentration of greenhouse gases (such as carbon dioxide) in Earth’s atmosphere has been increasing. Greenhouse gases absorb infrared radiation emitted by the ground. The greater the concentration of greenhouse gases, the more energy is absorbed by the atmosphere and the greater the air temperature. If the concentration of greenhouse gases leveled off (stopped increasing), what would happen to the air temperature?

• Less energy would be absorbed by the atmosphere, causing air temperature to decrease back to the level it was 150 years ago.

• Air temperature would continue to rise but only until the amount of energy emitted by the atmosphere balances the amount absorbed by it.

• The amount of energy being absorbed would exceed the amount emitted to space, causing air temperature to rise indefinitely.

Why does sunshine feel warmer in the middle of the day during the summer months and in places closer to the equator?

• Earth’s surface faces the sun more directly.

• Earth’s surface is closer to the sun.

• Earth’s albedo is lower.

The initial source of Earth’s internal thermal energy was

__________ .

The flux of solar energy from Earth’s surface is about 4000 times _______ than the flux of internal energy from its surface.