Ozone Finally Showing Signs of Recovery: Study

Finally, the world can rejoice over some good news about the environment. The Earth's protective ozone layer, which shields us from harmful ultraviolet rays, is showing signs of recovery, according to a new United Nations (UN) report released Wednesday.

This atmospheric layer is slowly rebuilding itself after years of dangerous depletion, which left a giant hole over Antarctica. But this gap has now stopped expanding, and experts are crediting the ozone's recovery to the phasing out of harmful man-made chemicals used in refrigerators, air conditioners and aerosol cans.

"It's a victory for diplomacy and for science and for the fact that we were able to work together," chemist Mario Molina, who won a Nobel Prize for his research into the ozone layer, told The Associated Press.

Once scientists realized that chlorofluorocarbons, or CFCs, were eating away at the Earth's ozone, leaders enacted the 1987 Montreal Protocol banning such chemicals. This, in turn, would prevent two million cases of skin cancer annually by 2030, according to the UN Environment Programme (UNEP), which co-produced the report with the World Meteorological Organization (WMO).

NASA's Dr. Ken Jucks told BBC News that humans "have started to do the right thing in order to convert the atmosphere back towards what it was before the industrial revolution started."

Nearly 30 years later, the ozone is just starting to heal. It will take until 2050 for the ozone layer in the mid-latitudes to return to what is was in the 1980s, while areas around Antarctica will take until 2075.

While past studies have found slowing ozone depletion, the new UN report is the first to show signs of an increase in total ozone, Geir Braathen, a WMO senior scientific officer, told Reuters.

The hole was largest in 2006 at about 30 million square kilometers, but now it's shrunk to about 20 million square kilometers - still big enough for the Moon to pass through.

There is a catch, however. Despite banning ozone-depleting CFCs, rising levels of other greenhouses gases in the atmosphere have "the potential to undermine these gains," the report said.

One of the substances that was supposed to have been phased out - carbon tetrachloride - is still present in the atmosphere, suggesting illegal use of the chemical.

"The challenges that we face are still huge," UNEP Executive Director Achim Steiner said in a news release. The success of the Montreal Protocol should encourage further action not only on the protection and recovery of the ozone layer but also on climate."

[Credit: NASA]