What is ozone layer? The ozone layer is a layer of ozone which blocks harmful ultraviolet light to reach the surface of the earth.
With this important role of ozone, ozone depletion is happening right now.
Human is responsible for ozone depletion. There were many chemicals substances we made and we realized the impact just after they damage our environment.
Even after CFC is banned, CFC can stay in the atmosphere for 120 years. It is our job to minimalize the usage of environment-harmful substances.