describe two changes that are harmful.explain why its harmful.how can we prevent them?

Dear student 1. Nuclear weapons blast 2. Depletion of ozone layer Reason : 1. Due to this phenomenon a drastic radiation of radioactive substances taken place which is very harmful for all living beings 2. The gas chlorofluorocarbons are responsible for the damage of ozone layer which causes the ultraviolet rays coming from the Sun reached to the surface of earth's which causes the skin cancer Regards