Dale Shannon, of Chisnallwood Intermediate School, asks :-
If the ozone hole gets too big will people start to die?
Greg Bodeker, an atmospheric physicist with the National Institute for Water and Atmosphere at Omakau, responded.
First let me tell you a few things about the ozone hole which forms over Antarctica from about August to November each year. The ozone hole never comes over New Zealand. Ozone is a gas in the atmosphere that absorbs ultraviolet light (UV) from the sun. UV damages our skin and after many years may cause skin cancer. The hole in the ozone layer isn't really a hole, it's just a place where the ozone layer is thinner. The thinner layer absorbs less UV and so more UV reaches the ground where it can harm people.
Now let's get back to answering your question. The ozone hole would have to get much bigger before people start to die. Fortunately it's never going to get that big. The ozone hole is caused by man-made chemicals, called CFCs, that destroy ozone. Soon after scientists discovered the ozone hole in 1984, governments from all over the world got together and decided to pass laws that would stop industries making CFCs. Thanks to this world wide cooperation, the amount of CFCs in the atmosphere is falling and we expect that the ozone hole will start to shrink. CFCs last for many years in the atmosphere so it will take a while before they're all gone. Scientists in New Zealand and all over the world have been doing research on this problem and we predict that by 2070 the ozone layer will be back to normal.