Australia and NZ dodge worse UV exposure

Scientists say Australia and New Zealand would be living under an enormous hole in the ozone layer if not for global co-operation.

Australians and New Zealanders would be feeling some serious sunburn had it not been for a global treaty, scientists say.

A new paper, co-authored by Richard McKenzie of Mew Zealand's National Institute of Water and Atmospheric Research, says a massive hole in the ozone layer that would have stretched across the Tasman has been avoided thanks to the 1987 Montreal Protocol.

The scientists estimate that if unchecked, the hole in the ozone layer would have grown by more than 40 per cent and that UV exposure in New Zealand and Australia, which already have among the highest skin cancer mortality rates, would have increased by about 12 per cent in that time.

The Montreal Protocol was an international treaty that restricted the use of chlorine and bromine, both ozone-depleting substances.

Thanks to the deal, the hole in the ozone layer is expected to be gone by 2050.

The research team, which also includes Dutch and British scientists, used state-of-the art 3D atmospheric modelling to reach their conclusions, which have been published in Nature Communications.

But Dr McKenzie said UV exposure and sun cancer were still serious issues in Australasia.

"This paper shows what a great job we've done with the Montreal Protocol but we mustn't lose sight of the fact that we've still got a problem," he said.