If three or four generations of the southern hemisphere were to talk to each other, everyone would consider something different in normal weather. According to a new study by scientists at the American University of Colorado Boulder, it is due, among other things, the state of the ozone layer.
This part of the atmosphere affects the phenomenon called jet flow, and it has an impact on the weather. The jet flow was originally directed from west to east, but due to the ozone hole, it has in the past deviated from its route one degree to the south every decade.
This has, for example, resulted in rainfall that had previously impacted Australia, which ended up in the sea. There was also a greater concentration of salt in the oceans.
But data from satellites and climate simulations according to the study show that this bottling has stopped at the turn of the millennium and is now gradually returning to its original form. As a result, it could rain more in the south of Chile, Argentina and Australia in the future. Conversely, less rainfall would hit the center of South America or the east coast of Africa.
The findings of the study are groundbreaking in this respect, other scientists say. For example, Martyn Chipperfield of the University of Leeds, UK, told New Scientist that the ozone layer is being restored, while returning to the normal and the things that were affected by the hole.
Tugged with greenhouse gases
In a few decades, the weather could return to what it was almost a hundred years ago. Although ozone depleting substances are banned and most countries have already abandoned their production, chemicals that have already entered the atmosphere will remain in it for a long time.
Study director Antara Banerjee also points out that change will come at different places at different times. For example, in the northern hemisphere, the ozone layer will return to what it was in the 1980s, after 2030. But in most of the southern hemisphere, it will be around 2050. And above Antarctica, where the hole formed, reconstruction after 2060.
However, this does not guarantee 100% success. "We still have to fight climate change," Chipperfield says.
"It's a tug of war between the restoration of the ozone layer and increasing carbon dioxide emissions," Banerjee agrees in The Guardian. "In the future, ozone could dominate and return the flow back to the equator. But once the recovery is complete, carbon dioxide can turn the flow back south," he adds.
Reducing the ozone hole
Ozone depletion was caused by so-called freons, chemicals in refrigeration equipment and aerosols used since the 1930s. Freons in the atmosphere lowered the ozone content until an ozone hole was formed above Antarctica. Almost all countries in the world that committed to ban the production of ozone-depleting substances agreed on the need for remediation in 1987 in the Montreal Protocol.
According to Alexei Karpechek of the Finnish Meteorological Institute, research has also shown how unified action by many states can work. "We see that coordinated action works. This is an important message not only for us but also for those emitting greenhouse gases. It shows that we can affect the planet's climate in both directions - in the wrong way and when we try to avert damage that we committed, "he told The Guardian.
Illustrative photo. | Photo by NOAA / NASA