More than 30 years after scientists first spotted a hole in the atmosphere’s protective ozone layer over the South Pole, they are seeing the “first fingerprints of healing,” researchers reported today (June 30).
Measurements of the ozone hole taken in September revealed the breach has shrunk by more than 1.5 million square miles (4 million square kilometers) — about half the area of the contiguous United States — since 2000.
The researchers attributed the ozone’s recovery to the continuing decline of atmospheric chlorine originating from chlorofluorocarbons (CFCs). These chemical compounds, once commonly used in aerosols, dry cleaning and refrigerators, were banned when nations around the world signed the Montreal Protocol in 1987 in an effort to repair the ozone hole. [Image Gallery: Life at the South Pole]
“We can now be confident that the things we’ve done have put the planet on a path to heal,” lead author Susan Solomon, an atmospheric chemist at the Massachusetts Institute of Technology (MIT), said in a statement. “We got rid of them [CFCs], and now we’re seeing the planet respond.”