We may have spent decades getting ourselves into the mess that is the depletion of the ozone layer, but now new research suggests it’s on the healing path thanks to our concerted effort to reduce harmful gases.
It has been almost 30 years since nations around the world signed the Montreal Protocol to ban the use of chlorofluorocarbons (CFCs) from products like aerosols and refrigerators to prevent the depletion of the ozone layer, but it’s only now we’re beginning to see the results of this action.
New research conducted by scientists at MIT in the US has, for the first time, shown evidence of the “first fingerprints of healing” of the planet’s protective layer, which limits the effects of the sun’s UV rays.
This is not to say that the ozone is near where it should be, rather the readings obtained for September 2015 showed that it had shrunk by 4m sq km since 2000, when ozone depletion was at its peak.
To determine whether the ozone had indeed recovered, the researchers, led by Susan Solomon, monitored the ozone changes with season and altitude and then attributed the ozone’s recovery to the continuing decline of atmospheric chlorine originating from CFCs.
These readings can be determined as it’s been shown that ozone depletion is a timed event beginning in late August over Antarctica, where it continues to grow to its full size by the beginning of October.
Despite the damage chlorine causes to the ozone layer, the gas only becomes harmful if sunlight is present and the atmosphere is cold enough to create polar stratospheric clouds that instigates the chlorine chemistry.
Solomon and her team, however, wanted to examine ozone depletion before it reaches its peak, which meant examining it for the month of September between 2000 and 2015 while also tracking meteorological changes during this period.
Despite their readings showing that September 2015 saw a record size hole in the ozone layer, it was determined to be a result of the eruption of the Chilean volcano, Calbuco, in that year.
If this trend of a shrinking ozone layer hole continues, Solomon has said that, barring catastrophic volcanic eruptions, it is possible that the hole could close permanently by the middle of this century.
“We can now be confident that the things we’ve done have put the planet on a path to heal,” Solomon said.
“Which is pretty good for us, isn’t it? Aren’t we amazing humans, that we did something that created a situation that we decided collectively, as a world, ‘Let’s get rid of these molecules’? We got rid of them, and now we’re seeing the planet respond.”