AP Environmental Science / Unit 9: Global Change
9.3 The Greenhouse Effect
Notes
Greenhouse gases ($\mathrm{CO_2}$, $\mathrm{CH_4}$, $\mathrm{N_2O}$, water vapor, CFCs) absorb infrared radiation from Earth's surface and re-emit it, warming the planet.
- Global warming potential (GWP): how much heat a gas traps compared with $\mathrm{CO_2}$.
Practice
Greenhouse gases absorb:
Heat radiated from Earth.
Methane's GWP compared with $\mathrm{CO_2}$ is:
About 25–30 times over 100 years.
Without any greenhouse effect, Earth would be:
It keeps Earth habitable.
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