Chemically unstable, ozone has few commercial applications; however, as part of the Earth's stratosphere, existing between 5 and 30 miles above the surface, it plays a vital role in the protection of the biosphere from the sun's deadly ultraviolet rays.
Despite news reports of an improving ozone layer, uncertainty over the impacts of illegal chlorofluorocarbon emissions threatens to undermine the longterm success of the Montreal Protocol. Though CFCs have been banned, there are other chemicals that contribute to the Antarctic ozone hole. The Arctic and mid-latitudes of the northern hemisphere could get there by the 2030s, and the mid-latitudes in the southern hemisphere could reach 1980s levels of ozone by mid-century.To reach that timeline of ozone recovery, the world is going to have to keep working to reduce other ozone-depleting chemicals and not throw a wrench into the recovery process in other ways.
According to the online report that was released by the United Nations this week, the infamous hole in the ozone layer could be totally healed by the 2060s - and in some areas of the world, it could be as soon as 2030.
"It's really good news", said report co-chairman Paul Newman, the chief Earth scientist at NASA's Goddard Space Flight Center. Actions under the Montreal Protocol over last more than 30 years have led to sustainable decreases in the atmospheric abundance of ozone-depleting substances (ODSs) like CFCs. The consequences of such high-energy UV rays included higher incidences of skin cancers, cataracts, loss of immune systems and lower production of food on land and fish in the oceans.
The emission of pollution containing chemicals such as chlorine and bromine has caused the ozone layer to deplete. In 1987, countries around the world agreed in the Montreal Protocol to phase out CFCs and businesses came up with replacements for spray cans and other uses.
In force since 1989, the Montreal Protocol has allowed the ozone layer to recover at a rate of 1 to 3 percent in recent years.
The ozone layer starts at about 6 miles (10 kilometers) above Earth and stretches for almost 25 miles (40 kilometers); ozone is a colorless combination of three oxygen atoms. Newman added that if we hadn't made these changes, two-thirds of the ozone layer would have been destroyed by 2065.
Since their banning in the 80's - experts say the ozone layer is slowly recovering. Banned CFC emissions are increasing in China, but the Chinese government has promised to fix the problem.
The United Nations' latest summary on the state of the ozone layer is a breath of fresh air for those thinking the environment is beyond fix, showing we're on track for the stratospheric column of ozone to return to 1980's levels by the second half of this century. They can't yet say how much a healed ozone hole would warm Antarctica, but they also know the immediate effects of ozone depletion on the world and human health.
The replacements that are now being used to cool cars and refrigerators have to be replaced themselves with some chemicals that will not be worsening the global warming.