Greenhouse Gases
A reading discusses the vibrational modes of water vapor and carbon dioxide (CO2) molecules in detail and explains why these gases act as greenhouse gases.
- Use the associated Reading from Prof. David Archer’s book “Global Warming: Understanding the Forecast”, available at (pg. 29-32), for a detailed description of how chemical bonds respond to incident IR light.
- Explain that due to electrical dipole moments developed during molecular vibrations, some bonds absorb IR energy of specific frequencies.
- Use this reading to explain the various vibrational modes in polyatomic gas molecules such as water vapor and carbon dioxide (CO2).
- Reiterate that the absorption of incident IR radiation by these gas molecules in certain vibrational modes makes them greenhouse gases.