Source: ARM and the U.S. Department of Energy. Adapted with permission.
As far back as ancient Greek and Roman times, people built structures that created an indoor environment suited to growing plants throughout the year. This enabled the gardener to establish a measure of control over growing conditions and extend the growth period into the colder seasons of the year. In this manner, the gardener was better able to provide fresh fruits and vegetables when needed. Today these structures, called greenhouses, are usually made of glass or plastic, but they still allow us to maintain year-round greenery.
There are similarities between a greenhouse and the Earth’s atmosphere. During the day, the sun’s rays shine on the Earth. Gases in the Earth’s atmosphere trap some of this energy created by the sun and help warm the planet. Without this “greenhouse effect,” the Earth would be too cold for life as we know it. But if the amount of greenhouse gases in the atmosphere increases, then more energy will be trapped, and the Earth will get warmer and warmer.
The way that heated air behaves in a greenhouse is also different in some ways from heated air in the Earth’s atmosphere. For example, once the air in a greenhouse is heated, it has no way to escape. The Earth’s atmosphere is more complicated, as you can see in the illustration that shows the different ways solar energy interacts with the atmosphere.
Climate scientists around the world study greenhouse gases and the ways they affect global climate. By making your own small greenhouse in this activity, you can recreate the greenhouse effect and measure its effect on temperature.
For more activities and information about climate science, along with lesson plans and resources for teachers, visit http://education.arm.gov.