Key Idea.
Section 1
Gases Interact with Energy
The atmosphere is transparent to sunlight but opaque to heat. Greenhouse gases like carbon dioxide （CO2） let solar energy in but interact strongly with the outgoing energy (heat) leaving Earth.
This selective interaction is key. These gases absorb the heat radiating from the ground, preventing it from passing straight out into space.
Section 2
Greenhouse Gases Redirect Energy
After absorbing heat, these gas molecules release it in all directions. Crucially, they send a significant portion of it back down toward the surface. This is called redirecting energy.
Instead of escaping, the energy is recycled back to the surface. This "blanket" effect keeps the planet warmer than it would be otherwise.
Section 3
Concentration Increases Trapping
The more greenhouse gases in the atmosphere, the more effective this trap becomes. A higher concentration means more molecules are available to block the exit.
This results in a decrease in the energy leaving the Earth system. The energy is stuck in a loop between the atmosphere and the surface.
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Section 1
Gases Interact with Energy
The atmosphere is transparent to sunlight but opaque to heat. Greenhouse gases like carbon dioxide （CO2） let solar energy in but interact strongly with the outgoing energy (heat) leaving Earth.
This selective interaction is key. These gases absorb the heat radiating from the ground, preventing it from passing straight out into space.
Section 2
Greenhouse Gases Redirect Energy
After absorbing heat, these gas molecules release it in all directions. Crucially, they send a significant portion of it back down toward the surface. This is called redirecting energy.
Instead of escaping, the energy is recycled back to the surface. This "blanket" effect keeps the planet warmer than it would be otherwise.
Section 3
Concentration Increases Trapping
The more greenhouse gases in the atmosphere, the more effective this trap becomes. A higher concentration means more molecules are available to block the exit.
This results in a decrease in the energy leaving the Earth system. The energy is stuck in a loop between the atmosphere and the surface.
Book overview
Jump across lessons in the current chapter without opening the full course modal.
Continue this chapter