Ozone layer shows steady recovery

The recovery of the ozone layer in the stratosphere is so well established that it should be restored to 1980 levels by the middle of the century. Eun-Su Yang of the Georgia Institute of Technology says that 25 years of data confirm that the Montreal Protocol of 1987 and subsequent regulations have prevented further depletion of the ozone layer. Scientists agree that the thinning of the ozone layer stopped in 1997. The ozone layer in the stratosphere protects people from harmful ultra-violet radiation. Its depletion was caused by chemicals such as CFCs used in some refrigerants such as R11 and R12 used for air conditioning and aerosol propellants. Eun-Su Yang explains that it was in 1980 that a marked thinning of the ozone layer over Antarctica was first observed.