LiveScience: With a boost from Mother Nature, the worldwide ban on ozone-depleting chemicals stopped Arctic ozone from disappearing and forming an "ozone hole" similar in size to Antarctica's, a new study finds. "It seems like we did just the right thing at the right time," said Susan Solomon, an atmospheric chemist at MIT and lead study author. "It's quite a success story." Looking back at some 50 years of Arctic ozone records, Solomon and her co-authors found no evidence that Arctic ozone levels have dropped...