Since it was discovered in 1985, the Antarctic ozone hole has been a potent symbol of humankind’s ability to cause unintended environmental harm. But now comes a glimmer of good news: The void in the ozone layer is shrinking. “It’s a big surprise,” says Susan Solomon, an atmospheric chemist at the Massachusetts Institute of Technology in Cambridge. “I didn’t think it would be this early.”
Although the hole will not close completely until midcentury at the earliest, the healing is reassuring to scientists who pushed for the Montreal Protocol. The 1987 international agreement phased out the industrial production of chlorofluorocarbons (CFCs): chlorine-containing chemicals that help trigger the destruction of stratospheric ozone, which screens out cancer-causing ultraviolet light. “You want to be sure that the actions we’ve taken have had the intended effect,” says Solomon, who led the study published online by Science this week.
And here's the money quote:
“The fact that we’ve made a global choice to do something different and the planet has responded to our choice can’t help but be uplifting,” she says.