Why Should We Care?

The many faces of energy and the conversions of energy between these forms are central to the modern North American lifestyle. We rely on the transformation of energy stored in fossil fuels or other energy “sources” to power everything from our vehicles to our computers. However, our dependence on fossil fuels as a supply of energy is altering the energy balance that maintains our climate, as fossil fuel combustion produces greenhouse gases. The mechanism by which greenhouse gases warm the atmosphere is also founded upon energy conversions.

Open the Collisional Heating Learning Tool. to observe how greenhouse gases facilitate the energy conversions that result in atmospheric warming. Move the purple bar to one of the peaks in carbon dioxide’s IR absorption spectrum, so that the carbon dioxide molecule will absorb the photons of IR radiation. Then, observe the energy conversion that takes place.

Your Turn

Electromagnetic radiation, such as IR radiation, possesses radiant energy. When IR radiation is absorbed by a greenhouse gas molecule, such as carbon dioxide, what energy transformation has occurred? Use the Collisional Heating Learning Tool. as necessary.