Ozone Layer Grows Thinner Over North

The Earth’s protective ozone layer is thinner than ever over the Northern Hemisphere, but has yet to develop an “ozone hole” like that over the Antarctic, U.N. officials say.

The ozone layer was 15 percent to 25 percent thinner over the Arctic during March this year than it was a year earlier, said the World Meteorological Organization. The worst affected area was over the North Pole and north-central Siberia.

“This situation is going to get worse before it gets better” because of the abundance of man-made chemicals that destroy ozone, Eirah Gorre-Dale, spokeswoman for the agency, said Friday.

The ozone layer, up to 30 miles above the Earth’s surface, absorbs ultraviolet rays from the sun that would be dangerous to people, plants and animals below.

Excess ultraviolet radiation can increase the incidence of cataracts and skin cancer, health experts say.