But there is a significant pending problem in the ozone layer. Each year, a large hole appears in it. It is not an actual hole, like a hole in a pocket, but a thinning in the layer that shows up on satellite pictures. The “hole” is located over Antarctica. It covers an area about the size of the United States. Experiments done in Antarctica show that the hole in the ozone layer appears to let in twice as much ultraviolet radiation as normal, according to measurements researchers made there only about two years ago. Over the whole Earth, the ozone layer has been depleted, or weakened, by an average of about 2 percent, scientists say Experts are concerned that extra radiation getting through to Earth’s surface could lead to problems in the future. During the next century, extra ultraviolet radiation could cause millions of new cases of skin cancer.
Scientists say that synthetic chemicals called chlorofluorocarbons are responsible for eating the hole in the ozone layer. Chlorofluorocarbons, called CFCs for short, are industrial chemicals used in air conditioners, spray cans, foam food containers and other things. It is important to understand that several specific gases such as water vapor, carbon dioxide, and methane keep ground temperatures at a global average of about 60 degrees farenheit. Without them the average would be below the freezing point of water. The gases have this effect because as incoming solar radiation strikes the surface, the surface gives off infrared radiation. The effect is comparable to the way in which a greenhouse traps heat and that is how we got the name greenhouse effect.