<p>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 Organization (WMO) said on Friday.</p>.<p>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.</p>.<p>"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.</p>.<p>Nullis, asked whether less pollution during the pandemic had played a role, said: "It was completely unrelated to COVID."</p>
<p>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 Organization (WMO) said on Friday.</p>.<p>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.</p>.<p>"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.</p>.<p>Nullis, asked whether less pollution during the pandemic had played a role, said: "It was completely unrelated to COVID."</p>