A huge hole in the ozone layer over the Arctic is set to grow even larger this spring as a blast of cold weather combines with returning sunshine and lingering air pollutants.
The hole over the Canadian Arctic is already thought to be around 770,000 square miles (two million square kilometres) or around the size of Greenland.
But environmental scientists are predicting the gap in the Earth's protective atmospheric layer could grow even larger this spring when the sunshine returns to the region after the long, dark winter.
According to Science magazine, a record low temperature in the Earth's upper atmosphere could release chemicals which destroy the layer.
Ozone is a gas composed of three oxygen molecules which can be hazardous to our health on the ground, but in the upper atmosphere it protects us by soaking up ultraviolet radiation from the sun.
Without it, the planet's surface would be exposed to dangerous levels of UV-B rays which can shred DNA, leading to mutations that cause cancers.
Towards the end of the 20th Century, the ozone was found to have been depleted by the now banned chlorofluorocarbons (CFCs), which react with the ozone as they break down.