'Rather unusual' ozone hole over the Arctic has closed, United Nations says

A "record level" ozone hole that appeared over the Arctic in March has now closed, the UN World Meteorological Organisation says.

A record hole in the ozone layer above the Arctic has closed, the United Nations says. Source: Copernicus Atmosphere Monitoring Service

Ozone depletion over the Arctic hit a "record level" in March, the biggest since 2011, but the hole has now closed, the UN World Meteorological Organisation (WMO) says.

The springtime phenomenon in the northern hemisphere was driven by ozone-depleting substances still in the atmosphere and a very cold winter in the stratosphere, WMO spokeswoman Clare Nullis told a UN briefing in Geneva.

"These two factors combined to give a very high level of depletion which was worse than we saw in 2011. It's now back to normal again ... the ozone hole has closed," she said on Friday.

Ms Nullis, asked whether less pollution during the pandemic had played a role, said: "It was completely unrelated to COVID."

Last month, the Copernicus Atmosphere Monitoring Service (CAMS) said the hole was "rather unusual".

"While we are used to ozone holes developing over the Antarctic every year during the Austral spring, the conditions needed for such strong ozone depletion are not normally found in the Northern Hemisphere," they said.