Greenhouse effect

Science

Definition

The natural process by which certain gases in Earth's atmosphere (CO₂, methane, water vapor, N₂O) trap outgoing infrared radiation, warming the planet's surface. Without it, Earth would be about 33°C colder. Human activities have enhanced this effect by increasing greenhouse gas concentrations.

How It Works

  1. Solar radiation passes through the atmosphere and warms Earth's surface
  2. Earth's surface emits infrared (heat) radiation back toward space
  3. Greenhouse gases absorb and re-emit some of this infrared radiation
  4. Re-emitted radiation warms the lower atmosphere and surface
  5. Increased greenhouse gas concentrations trap more heat, enhancing the effect

Examples

  • CO₂ from burning fossil fuels increasing atmospheric heat trapping
  • Methane from livestock and landfills acting as a potent greenhouse gas
  • Venus having extreme greenhouse effect with surface temperatures over 450°C

Related Terms

Global warming Climate change Fossil fuels Atmosphere layers

Study This Concept

Practice greenhouse effect with free review games in these units:

AP Environmental Science Unit 9: Global Change Earth Science Unit 7: Climate and Climate Change