|An interactive in which students can experiment
with greenhouse gas levels to see their collective affect
on Earth's surface temperatures
Many scientists believe the "greenhouse effect" is a poorly-named phenomenon. Most people immediately think of a greenhouse as a place that warms trapped air, much like a car in the sun heats up when its windows are closed. This is not the case with our atmosphere, which is a porous layer through which electromagnetic radiation, both short wave, visible (and ultraviolet) light energy and longer wave, infrared energy, travel.
Visible light, as well as ultraviolet light, travels from the Sun to the Earth. Some of this energy (about 1/3) is reflected back to space by the upper atmosphere, but most of the rest travels unimpeded to the surface of the earth where it is absorbed, The earth radiates infrared energy out into space. However, some of this energy gets "captured" by a layer of GHG (greenhouse gases) as it leaves Earth. Some of the energy captured by these little critters is sent back into space; but some of it gets deflected back to Earth. The rest is absorbed by other CO2 (or other GHG) molecules. and the process is repeated.
Even though it's an inaccurate metaphor, the name "greenhouse" effect still persists. And the gases that are part of our atmosphere are sorted out according to the way they redirect energy or let it pass through. Greenhouse gases - carbon dioxide, water vapour, and methane - are champs at capturing the heat energy and redirecting it everywhere, including back towards Earth.
The "greenhouse" effect is crucial for all life on this planet. If none of the heat energy were redirected toward Earth, our temperatures would plummet precipitously. But there is sometimes too much of a good thing.
|For more information|
After working with this interactive, students will be able to describe the relationship between CO2 levels in the atmosphere and the temperature of the earth
|Can be used with existing lesson plans on|
Greenhouse gases; Earth's atmosphere; greenhouse effect; radiation; solar energy
|Additional ways to use this asset to enrich your curriculum|
|The Greenhouse Effect (PDF | Word)|