The greenhouse effect | Physics | Khan Academy

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Earth receives a spectrum of electromagnetic radiation from the Sun which peaks in the visible range. Some of this light makes it to Earth's surface and is absorbed. The absorbed light is converted to thermal vibrations of charged particles, which then radiate infrared light. Greenhouse gases in the atmosphere (including carbon dioxide, methane, and water vapor) absorb the infrared light and then re-emit it in random directions. Some escapes to space, and some remains trapped in the atmosphere. The greenhouse effect keeps Earth warm enough to be habitable. However, human activities are increasing greenhouse gas concentrations and are thereby affecting Earth's climate system. Solutions to this problem include solar, wind, and nuclear energy, which do not emit greenhouse gases during operation.

00:00 - Intro
00:44 - Greenhouse effect overview
05:05 - Solar spectrum at the top and bottom of atmosphere
07:59 - Why do greenhouse gases absorb infrared light?
11:21 - Increasing greenhouse gases and climate change

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