When the world takes action together, it can really solve big problems. An important case: The ozone hole, which if everything goes according to the plan, could be cured until the 2060s, according to a new report by the United Nations.
According to the report, a 10-year international treaty banning ozone-depleting chemicals has led to their decline and "much more severe depletion of ozone in polar regions has been avoided." Much remains to be done, but that certainly falls under the category of good news.
"We are at the point of repetition," Paul Newman, a scientist assisting with NASA's Ozone Watch, and chairing the UN report, told Earther.
The report is closed every four years and this is the fifth recurrence. It is watching an environmental problem of the 1980s that we still feel the results of today. The ozone hole is driven by a range of chemicals commonly found in aerosol cans, air conditioners and refrigerators, called chlorofluorocarbons and hydrochlorofluorocarbons. These chemicals release chlorine into the stratosphere, which in turn can break down the ozone molecules. When this happens, more ultraviolet light from the sun makes it surface, increasing the risk of bad things like skin cancer. The problem was particularly remarkable in Antarctica, where an ozone hole began to form every spring.
Scientists identified chemicals as problematic and policy makers were actually acting. The Montreal Protocol was impregnated in 1987. After 30 years, the ozone hole is still annual. But the new report finally adds to a 2016 study that shows that the ozone hole has been on the surface since 2000. If everything goes according to the plan, the ozone levels in the region could return to pre-holes in 40 years.
In other areas where ozone depletion was less severe, a return to smoothness could come even earlier. The Arctic and the mid-latitudes of the northern hemisphere could reach the 2030s and the average hemisphere in the southern hemisphere could reach 1980 levels by the middle of the century.
To achieve this chronological order of ozone recovery, people should continue to work to reduce other ozone-depleting chemicals and not throw a key in the recovery process in other ways. On a few levels, there are some warning signs that scientists see.
The first is a mysterious concern in CFC-11, a chemical banned under the Montreal Protocol. Although outlawed, research published earlier this year has shown that it has risen since 2012. Most signs show that China is the culprit of illegal emissions and should stop to maintain recovery along the way.
Another factor is what happens to the fight to combat global warming. The ozone hole and climate change are generally separate problems, but they overlap a little. The effect of lower-atmosphere heating associated with increased greenhouse gases also leads to cooling in the stratosphere, which sits approximately 6-12 miles above the planet's surface. This may slow down the process of ozone depletion, which could accelerate recovery in some areas.
At the same time, the report notes that the rise in temperature due to greenhouse gas emissions alters planetary air circulation in ways that can lead to less ozone in the tropics and more in the Arctic and the middle latitudes. So, limiting greenhouse gas emissions – including those generated by substitution of ozone-depleting chemicals – is still probably a good idea.
The last issue is probably the most worrying because we know so little about it. The report raises concerns about what would happen if the world or even a ruthless state decided to cool the planet by sending tiny particles to the stratosphere. The process, known as geomechanics, has suffered with potential consequences here on the ground and is likely to be in the stratosphere.
"The problem with this is our level of knowledge about natural particle levels in the stratosphere is not that high," Newman said. "Geomechanics is quite challenging by disturbing the physical levels of particles in the stratosphere above that impact on ozone."
Well, let's not do that and instead of continuing to try to correct the ozone hole and solve the global warming here on the ground.