Last week, the United Nations Environmental Program's scientists released a report stating that the stratospheric ozone layer is showing signs of recovery, and predicted that it should be back to its 1980 levels ‒ before significant depletion had begun ‒ by 2050. The report credits the concerted international efforts, as mandated under the Montreal Protocol, for this breakthrough development. The UNEP claims that if it wasn't for the environmental treaty, there would have been 200 million cases of skin cancer annually by 2030.
This video shows ozone concentration levels in the southern hemisphere from 1979 to 2013 with each image corresponding to the day of the year with the lowest levels.