Ozone Wound Gets Opportunity To Heal Report Shows Decline In Levels Of Ozone-Destroying Chemicals

Ozone-destroying chemicals are declining in the atmosphere for the first time, according to researchers who say that means the ozone hole high above the Earth could start closing within 10 years.

“This is the very beginning of a change,” said Stephen A. Montzka, a National Oceanic and Atmospheric Administration scientist. “This is the first step toward the goal of closing the ozone hole” over the South Pole.

The high-altitude natural ozone layer forms a barrier against ultraviolet radiation from the sun. Excessive levels of UV radiation cause skin cancer in humans and damage many plants and animals.

Montzka said ground-level measurements on three continents and on two Pacific Ocean islands detected a reduction in the concentration of the group of industrial chemicals that erode the ozone layer. A report on the study is being published today in the journal Science.

“A detectable signal for ozone recovery is expected around 2005 or 2010,” said Montzka, a researcher in the NOAA laboratory in Boulder, Colo., and the first of eight coauthors of the study.

In 1987, 23 nations meeting in Montreal signed an agreement to gradually phase out manufacture and use of ozone-destroying chemicals. Amendments later added more chemicals to the list, and Montzka said tests now show the accord is beginning to have an effect.