The pilot and the co-pilot were killed as an Air Canada Express plane flying from Montreal collided with a ground vehicle upon landing at New York's LaGuardia Airport, Xinhua reported, citing local media. Pics/AFP

As the awareness around global warming increases, there is a need to understand why the ozone layer deserves to be protected. The layer in the Earth’s stratosphere has been depleting but it must be preserved to avoid harmful effects such as various types of skin cancers. On International Day for the Preservation of the Ozone Layer, here are interesting facts about the efforts in that direction