For more than 30 years scientists have monitored the ozone layer above Antarctica. Professor David Karoly of the University of Melbourne and atmospheric scientist says the size of the hole fluctuates in size every year due to two important factors.
“It’s the increase in ozone-depleting chemicals in the atmosphere and a very special cold conditions that occur in winter and spring over Antarctica which creates a catalytic ozone destruction vessel,” reports ABC.
On October 2, the ozone hole reached its largest size to date according to the UN’s weather and climate agency and NASA’s Ozone Hole Watch . At nearly four times the surface area of Australia, the hole covered a 17.5 million square mile area over Antarctica.
In contrast, last year the hole was one of the smallest on record says Paul Krummel of Australia’s Commonwealth Scientific and Industrial Research Organization. He says meteorological conditions determine the size of the hole each year and that it isn’t a permanent situation.
“This year it is extremely cold over the Antarctic,” he said. “And by this time of year normally warm air is starting to egress into that area and this hasn’t happened yet.”
The ozone layer absorbs UV rays, thereby protecting life on the planet. UV rays damage DNA causing cancer in humans. In areas where the layer is thin or there is a hole, people, plants and animals have a high risk of sustaining cellular damage from those rays.
Scientists expect the hole to patch itself and ozone to recover in time.
“We expect in the southern hemisphere that the ozone hole will not completely recover for another 40 to 60 years, when it recovers back to pre-1980 levels when the ozone hole was first discovered,” said Professor Karoly.
Until then, people in Southern Australia should protect themselves by covering up and using sun block.
