“ozone hole” is healing
The ozone layer above Antarctica is healing. It has healed so much stopping many changes in Southern Hemisphere’s atmosphere. The whole world gets credit.
Studies suggest that the Montreal Protocol of 1987, the agreement to stop producing ozone-depleting substances could be the key player in achieving this result. This has stopped some troubling changes in air currents around the Southern Hemisphere.
Ozone depletion drove the Southern jet streams further south than usual (Jet streams are fast air currents). This resulted in changes in rainfall and ocean currents.
After about a decade of signing the protocol, the migration suddenly stopped. Using computer simulations and models, researchers found that this pause in the movement was not driven by natural shifts in winds along. This could be explained only through changes in the Ozone layer.
So the impact from the Montreal Protocol seems to have paused or slightly reversed the Southern migration of the Jetstream. For counties like Australia, changes in Jetstream have resulted in an increase in the risk of drought by pushing the rain away from coastal areas. After the effects generated by the healing of the Ozone layer, these rains may return.
“The ‘weather bands’ that bring our cold fronts have been narrowing towards the south pole, and that’s why southern Australia has experienced decreasing rainfall over the last thirty years or so,” says Ian Rae, an organic chemist from the University of Melbourne who was not involved in the study. “If the ozone layer is recovering, and the circulation is moving north, that’s good news on two fronts (pun not intended).”
Still, this may not be a situation to celebrate long. Although the usage of other harmful gases is limited, rising levels of co2 can again bring bad results and industrial regions in China still emit Ozone-depleting gases.
“We term this a ‘pause’ because the poleward circulation trends might resume, stay flat, or reverse,” says atmospheric chemist Antara Banerjee from the University of Colorado Boulder.
“It’s the tug of war between the opposing effects of ozone recovery and rising greenhouse gases that will determine future trends.”
The Montreal Protocol is proof that if we take immediate action environmental damages can be healed.