by Robin McKie
It is popularly viewed as one of the greatest environmental success stories of modern times. Exactly 30 years ago, UK scientists announced they had discovered a hole in the ozone layer in the atmosphere above Antarctica.
The hole threatened to spread, allowing increased levels of cancer-causing radiation from the sun to reach the ground. Within a few years of the discovery it was agreed to set up the Montreal Protocol, which banned the manmade chemicals responsible for depleting ozone in the upper atmosphere.