This image shows the amount of ozone in Earth's stratosphere. The colors represent different amounts of ozone with purple and blue indicating very low levels of stratospheric ozone. Yellow and green represent higher levels of ozone. Notice the blue and purple spot over the South Pole which is the Antarctic ozone hole. The ozone levels are monitored by satellite. Click on image for full size (31K GIF) Courtesy of NASA

The ozone layer in the stratosphere is important for life on Earth because it shields the Earth from harmful solar radiation. Since 1974 scientists have been watching a hole grow in the ozone layer above the South Pole but now they have some good news. They say that the Antarctic ozone hole may close by 2050!

The ozone hole over Antarctica formed mainly by Chlorofluorocarbons (CFCs) destroying ozone. CFCs are a human developed compound that people have used since the 1930’s in refrigerators and air conditioners. The chemical remains in the atmosphere, destroying the ozone, for decades. CFCs are able to break ozone apart when a chlorine atom from a CFC molecule, broken off by UV radiation, attacks an ozone molecule.

In 1987, countries around the world agreed to gradually produce less CFCs when they signed the Montreal Protocol, an international treaty to eliminate the production and consumption of ozone-depleting chemicals.

It looks like our efforts to cut down on activities that release CFCs are making a difference according to a recent study that says CFCs are declining. A United Nations report released Monday said CFCs in the atmosphere have been declining since 2000. “We are now at a point where the atmosphere can actually remove CFCs faster than they are being released into the atmosphere,” said Paul Fraser, a scientists and one of the authors of the United Nations report.