The Ozone is healing
It wasn't too long ago — the mid-1980s, to be exact — that scientists made a deeply troubling discovery: The ozone layer of Earth, which shields us from the sun's dangerous ultraviolet rays, each spring opened a massive hole over Antarctica. Even worse, the ozone layer all around the world was also being steadily thinned. This supported assertions of ozone depletion going back to the 1970s.
The chief culprit was chlorofluorocarbons (CFCs), chemicals that were used at the time in common items like hairspray and refrigerants. Skin cancer, cataracts, severe harm to plants and animals — studies that followed the discovery painted a dire picture of future human existence, if we didn't do something quick to stop it.
That something was the 1987 Montreal Protocol, which banned the production of CFCs and other ozone-depleting chemicals. And while the news turned slowly better for the ozone (and us) over the past two decades, the latest check-up from 2018 is an undeniable win: A United Nations report says the ozone, including the gaping hole over Antarctica, will be fully healed by the 2060s.
“It’s really good news,” said report co-chairman Paul Newman, chief Earth scientist at NASA’s Goddard Space Flight Center. “If ozone-depleting substances had continued to increase, we would have seen huge effects. We stopped that.”
High in the atmosphere, ozone shields Earth from ultraviolet rays that cause skin cancer, crop damage and other problems. Use of man-made chemicals called chlorofluorocarbons (CFCs), which release chlorine and bromine, began eating away at the ozone. In 1987, countries around the world agreed in the Montreal Protocol to phase out CFCs and businesses came up with replacements for spray cans and other uses.
At its worst in the late 1990s, about 10 percent of the upper ozone layer was depleted, said Newman. Since 2000, it has increased by about 1 to 3 percent per decade, the report said.
Source - PBS.org