The Greenhouse Effect

The Earth is surrounded by windows. We call these windows the atmosphere, a layer of air many miles up in the sky. As the sun shines on the Earth, the atmosphere lets the heat reach the ground, then prevents some of it from escaping back into space.
That's all fine. In fact, we need the atmosphere. Without it, the Earth would be as cold and lifeless as the surface of the moon. The problem is that our atmosphere is changing. Some of our favorite activities create gases that pollute the atmosphere. As those gases build up, the atmosphere keeps in too much heat.

What are Greenhouse Gases?
The most important is carbon dioxide, also known as CO2. All humans and animals produce CO2 every time we exhale, the but there's nothing we can do about that. The main source of CO2 is the burning of fossil fuels--coal, oil, and gasoline--and wood.
Another greenhouse gas is nitrogen oxide, which is given off by cars as we drive them and by coal-burning power plants as they generate electricity.
Still another is methane, which is created by rotting plants and by household garbage as it deteriorates in landfills. (Humans and other animals also create methane--everytime we pass gas.)

What is the Effect?
We've been creating all of these gases for a long time. But now we're producing too much of them and they are making the Earth a little hotter. Here's what could happen if average temperatures on Earth increases just a few degrees:
• Some of the ice around the North Pole and the South Pole would melt.
• That melted ice would cause the sea levels to rise.
• People living near sea level could be flooded.
• Some places would become too hot to live in.
• Many farmers' crops would no longer grow.
Some scientists now think that the average temperatures on Earth could rise by between 3 and 10 degrees Fahrenheit by the middle of the next century. If that happened, water levels could flood much of New York City. In Washington, D.C., water would flood the Lincoln Memorial and nearly reach the Capitol steps!
That's just the beginning. As things got even warmer, hundreds of different living creatures could die and become extinct, while many kinds of pests (such as rats and mosquitoes) could multiply in the warmer climate.

The Earth's Natural Remedies
Some gases are soaked up naturally. Sea water soaks up carbon dioxide, and so do the tiny organisms in the sea called plankton. But because plankton soaks up more CO2 in colder water, as the Greenhouse Effect warms up the oceans, the plankton will absorb less carbon dioxide.
Plants on land also soak up CO2, especially the trees in the mighty rainforests of the world. But because trees in the rainforests are being cut down and burned, there are fewer trees to soak up the greenhouse gases. What's worse, the burning of trees actually produces even more CO2, contributing to the greenhouse problem. In fact, rainforest burning is one of the greatest contributors to the Greenhouse Effect.

What Can You Do?
One big way to help is to cut down on the use of energy. Every time you turn on the lights, open the refrigerator, turn on the heat, or take a ride in the car, you are using energy--electricity, gasoline, and natural gas, for example. The power plants that generate the electricity and the automobile engines that burn gasoline all create vast amounts of CO2.