Antartica 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.
about two years ago. Over the whole Earth, the ozone layer has been weakened,.
by an average of about 2%, scientists say (Fisher 23). 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.
skin cancer problems. Scientists think that synthetic chemicals called.
chlorofluorocarbons are what is eating the hole in the ozone layer. .
Chlorofluorocarbons, called CFCs for short, are chemicals used in air conditioners,.
spray cans, foam food containers and other things.
Once CFCs get into the atmosphere, they join with other chemicals that are.
already there. During Antarctica's long, dark winter time, lower temperatures in .
.
the stratosphere cause ice crystals to form in the air. When the sun reappears over.
the horizon in October, it acts on the ice crystals and starts reactions between.
ozone and CFCs. So when the chemical reactions happen, the ozone breaks.
down(Fisher34). .
During the 1990's, the use of CFCs was expected to be cut in half. Fifty.
countries plan to sign an agreement governing the use of chemicals. A lot of.
people would still like to see an end to CFCs by the end of the century, which is.
not likely to happen. Scientists are not sure if the ozone layer will ever recover.
completely even if CFCs are taken away. But the limitation would keep the.
problem from getting worse, they believe, and in time the ozone layer might.
rebuild itself (Fisher 37).
It is important to understand that several gases like water vapor, carbon.
dioxide, and methane keep the temperature in the ground at a global average of.
about 60 degrees Fahrenheit.