Science: 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…