An environmental study cited an international treaty made over three decades ago as the main cause behind the recovery of the ozone layer over Antarctica. According to the study, the treaty was able to stop the effects of ozone depletion on the air current patterns on Earth.
The new study about climate change was published in the journal Nature. It focused on the global effects of the Montreal Protocol that was signed in 1987.
Effect Of Ozone Depletion
This international treaty was established with the goal of stopping the global usage of ozone-depleting substances in various products. The Montreal Protocol identified these substances as the main culprit in the depletion of the ozone layer.
According to the scientists, the worsening state of the ozone layer had caused drastic changes in the air currents that flow towards the planet's poles at high altitudes, which are referred to as jet streams. Due to ozone depletion, these jet stream have been driven further south than their usual patterns.
Changes in Earth's Jet Streams
The changes in the paths of the jet streams have led to increased rainfall in the affected regions. They also affected ocean currents. In Australia, for instance changes in the jet stream pushed away the rain from the coastal areas, which then increased the risk of drought.
"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," organic chemist Ian Rae, who was not part of the study, said in a statement. "If the ozone layer is recovering, and the circulation is moving north, that's good news on two fronts."
The Recovery Of The Ozone Layer
About a decade after the Montreal Protocol was enacted, environmental scientists have started noticing improvements in the jet stream patterns. According to their observations, the changes in the jet streams stopped, which strongly indicated that the ozone layer was healing. Authors of the new study noted that the protocol most likely played a huge role in the recovery of the ozone layer.
"Signatures of the effects of the Montreal Protocol and the associated stratospheric ozone recovery might therefore manifest, or have already manifested, in other aspects of the Earth system," the scientists wrote in the abstract of their study.