New data from NASA has shown that the hole in the ozone layer above Antarctica has remained at a more a less constant size for the last several years, despite scientists predicting that it would continue to shrink.
The hole in the layer of gas that protects the surface of the Earth from ultraviolet radiation remains at around the same levels as 2010. Until this point it had been contracting steadily ever since the chlorofluorocarbons (CFCs), which initially caused the hole, were banned at the Montreal Protocol in 1989.
Scientists are unsure exactly why the hole has proved to be so persistent; they point to the complex relationship between the climate and the ozone layer as the likely explanation. Despite this slowing of shrinking, scientists remain confident that it will continue to decrease in size over the next few decades. They point out that without the intervention of the Montreal Protocol in the late 1980s, the hole would have by now increased to a much larger, and extremely dangerous, size.
The Montreal Protocol remains one of the most important successes in the history of environmental policy and NASA’s recent data reveals just how crucial the treaty really was. The damage done to the ozone hole has proven more difficult to reverse than previously thought. This case should act as both a hopeful and a cautionary tale for lawmakers and those trying to influence them. We are surely past due for another success of this magnitude.