This picture shows what happens to energy from the Sun once it gets to Earth. Click on image for full size (168K JPG) NCAR

Once energy from the Sun gets to Earth, several things can happen to it:

• Energy can be scattered or absorbed by aerosols in the atmosphere. Aerosols are dust, soot, sulfates and nitric oxides. When aerosols absorb energy, the atmosphere becomes warmer. When aerosols scatter energy, the atmosphere is cooled.
• Short wavelengths are absorbed by ozone in the stratosphere.
• Clouds may act to either reflect energy out to space or absorb energy, trapping it in the atmosphere.
• The land and water at Earth's surface may act to either reflect energy or absorb it. Light colored surfaces are more likely to reflect sunlight, while dark surfaces typically absorb the energy, warming the planet.

Albedo is the percentage of the Sun's energy that is reflected back by a surface. Light colored surfaces like ice have a high albedo, while dark colored surfaces tend to have a lower albedo. The buildings and pavement in cities have such a low albedo that cities have been called "heat islands" because they absorb so much energy that they warm up.

This picture shows what happens to energy from the Sun once it gets to Earth. Click on image for full size (168K JPG) NCAR

Once energy from the Sun gets to Earth, several things can happen to it:

• Energy can be scattered or absorbed by aerosols in the atmosphere. Aerosols are dust, soot, sulfates and nitric oxides. When aerosols absorb energy, the atmosphere becomes warmer. When aerosols scatter energy, the atmosphere is cooled.
• Short wavelengths are absorbed by ozone in the stratosphere.
• Clouds may act to either reflect energy out to space or absorb energy, trapping it in the atmosphere.
• The land and water at Earth's surface may act to either reflect energy or absorb it. Light colored surfaces are more likely to reflect sunlight, while dark surfaces typically absorb the energy, warming the planet.

Albedo is the percentage of the Sun's energy that is reflected back by a surface. Light colored surfaces like ice have a high albedo, while dark colored surfaces tend to have a lower albedo. The buildings and pavement in cities have such a low albedo that cities have been called "heat islands" because they absorb so much energy that they warm up.

This picture shows what happens to energy from the Sun once it gets to Earth. Click on image for full size (168K JPG) NCAR

Once energy from the Sun gets to Earth, several things can happen to it:

• Energy can be scattered or absorbed by aerosols in the atmosphere. Aerosols are dust, soot, sulfates and nitric oxides. When aerosols absorb energy, the atmosphere becomes warmer. When aerosols scatter energy, the atmosphere is cooled.
• Short wavelengths are absorbed by ozone in the stratosphere.
• Clouds may act to either reflect energy out to space or absorb energy, trapping it in the atmosphere.
• The land and water at Earth's surface may act to either reflect energy or absorb it. Light colored surfaces are more likely to reflect sunlight, while dark surfaces typically absorb the energy, warming the planet.

Albedo is the percentage of the Sun's energy that is reflected back by a surface. Light colored surfaces like ice have a high albedo, while dark colored surfaces tend to have a lower albedo. The buildings and pavement in cities have such a low albedo that cities have been called "heat islands" because they absorb so much energy that they warm up.