Three key molecules that trap heat in the atmosphere, known as greenhouse gases, are:
- Carbon dioxide (CO2) : It absorbs infrared radiation emitted from the Earth's surface, causing the molecule's bonds to vibrate and trap heat, which warms the atmosphere
- Methane (CH4) : Methane has a more complex molecular structure than CO2, allowing it to absorb infrared light more effectively and trap heat more potently on a per-molecule basis
- Water vapor (H2O) : Naturally occurring in the atmosphere as part of the water cycle, water vapor also absorbs infrared radiation and contributes significantly to the greenhouse effect
These molecules absorb infrared radiation emitted by the Earth, preventing some of the heat from escaping into space and thereby warming the planet
. Other greenhouse gases include nitrous oxide and human-made chemicals like chlorofluorocarbons, but the three primary natural heat-trapping molecules are carbon dioxide, methane, and water vapor
