[Animals] Ozone hole: Why Antarctic wildlife is being 'sunburnt’

[Wolf.17]

 

For Antarctic wildlife, exposure to the Sun's damaging rays has increased in recent years, scientists say.

A hole in the ozone layer - the protective barrier of gas in the upper atmosphere - now lingers over the frozen continent for more of the year.

A major cause of ozone loss is believed to be the amount of smoke from unprecedented Australian wildfires, which were fuelled by climate change.

The study is published in the journal Global Change Biology.

Climate change biologist Prof Sharon Robinson told BBC News: "When I tell people I work on the ozone hole, they go: 'oh, isn't that better now?'"

Scientists working in Antarctica discovered the hole in the ozone layer in 1985 - by measuring the amount of solar radiation reaching Earth.

A large group of ozone depleting chemicals were responsible - primarily CFCs or chlorofluorocarbons - that were used as refrigerants. Every country agreed, in 1987, to phase out a group of ozone-depleting chemicals. It was an agreement known as the Montreal Protocol and is considered to be the most successful environmental treaty in history.

The ozone layer is now healing. "But there's a hole - an area where the ozone layer is very depleted - that appears every spring over Antarctica," Prof Robinson explained.

That ozone loss is particular to the polar continent, because of chemical reactions that occur in very low temperature, high atmospheric clouds. Those reactions break down ozone - eating a hole in the layer.

The annual appearance of this hole usually peaks in September and October, when most land-based plants and animals are safely tucked away under snow cover and marine animals are protected by extensive sea ice.

It is now lasting through to December - well in to the Antarctic summer. "That's when things will be exposed and most vulnerable," said Prof Robinson.

Certain types of ultraviolet radiation from the Sun, called UV-B rays, increase the risk of skin cancer and cataracts in humans, but researchers do not yet know if the same is true for Antarctic mammals and birds.

https://www.bbc.com/news/science-environment-68906013