The thin skin of our atmosphere keeps the earth from being an ice planet and makes it habitable. In fact, this is due to less than 0.5% of the air molecules. Of the energy from the sun that reaches the earth, almost 1/3 is reflected back into space, with the rest absorbed by the atmosphere and the surface of the earth.
Some of the energy that the earth absorbs is re-emitted as infrared (IR) radiation, a portion of which passes back out through the atmosphere into space. However, most of this IR radiation is absorbed by certain substances in the atmosphere, known as greenhouse gases, which re-emit this energy in all directions, trapping some of the heat.
The major greenhouse gases (GHGs) are water vapor, carbon dioxide, methane and ozone. Since the Industrial Revolution, human activity has been increasing the concentration of GHGs, which has changed the energy balance and is significantly altering the earth's climate.
Explore the simulation to see how greenhouse gases interact with infrared radiation.
Using the customization features, you can show select molecules or allow users to interact with specific photon sources.
Text adapted from Openstax Chemistry, Section 9.3 Stoichiometry of Gaseous Substances, Mixtures and Reactions.