Earth’s ozone layer appears to be healing

The situation for all of us looks pretty bleak at the moment but at least there’s a sliver of good news coming out of the scientific community.

Experts have confirmed that changes in the jet stream (fast air currents at high altitudes) are evidence of the recovery of the Earth’s protective ozone layer. Ozone, a type of inorganic molecule, exists in a layer of our planet’s stratosphere and is responsible for absorbing the sun’s harmful ultraviolet radiation.

Levels of ozone had declined to such a worrying degree that a 1987 agreement known as the Montreal Protocol put a stop to the use of ozone depleting substances (ODSs) around the world. A new study, published in the journal Nature, shows the Montreal Protocol has been successful.

‘This study adds to growing evidence showing the profound effectiveness of the Montreal Protocol. Not only has the treaty spurred healing of the ozone layer, it’s also driving recent changes in Southern Hemisphere air circulation patterns,’ said lead author Antara Banerjee, a CIRES Visiting Fellow at the University of Colorado Boulder who works in the Chemical Sciences Division of the National Oceanic and Atmospheric Administration (NOAA).

The study involved using computer simulations to detect whether certain patterns of observed wind changes were likely due to natural variability or a change in human-caused factors like emissions of ozone-depleting chemicals and carbon dioxide into the atmosphere.

‘The challenge in this study was proving our hypothesis that ozone recovery is in fact driving these atmospheric circulation changes and it isn’t just a coincidence,’ Banerjee said.

They showed that while rising CO2 emissions have continued expanding the near-surface circulation (including the jet stream) polewards, only the ozone changes could explain the pause in circulation trends.

‘Identifying the ozone-driven pause in circulation trends in real-world observations confirms, for the first time, what the scientific ozone community has long predicted from theory,’ said John Fyfe, a scientist at Environment and Climate Change Canada and one of the paper’s co-authors.

The scientists are wary of this trend being undone as carbon dioxide emissions continue to spiral out of control and climate change becomes a defining issue. How that plays out in the wake of the worldwide coronavirus pandemic remains to be seen.

The study has been published in the journal Nature.

Source: Metro News UK