今日のテキスト RESEARCHERS: OZONE LAYER ON THE MEND

Researchers say the hole in the ozone layer over Antarctica has shrunk in the last 15 years. The layer shields the Earth from harmful ultraviolet rays.
Scientists from the Massachusetts Institute of Technology, the University of Leeds and others published their findings in the journal Science. They found the hole shrank by four million square kilometers between 2000 and 2015. That's bigger than India.
Chlorofluorocarbons and other gases damaged the ozone layer. They were used in dry-cleaning solvents, refrigerators and aerosol sprays. Most countries have restricted emissions of those gases after signing the Montreal Protocol in 1987. The researchers say those efforts have put the planet on a path towards healing.