The hole in the ozone layer over Antarctica may be larger this year than in 2007, the United Nations weather agency said on Friday.

The ozone layer shields the Earth from damaging ultra-violet rays that can cause skin cancer. The Antarctic ozone hole is normally about the size of North America but its ultimate size depends on weather conditions.
"As the sun returns to Antarctica after the polar night, it is expected that ozone depletion will speed up," the World Meteorological Organisation said in its latest Ozone Bulletin.