Why does life on land require an ozone layer?

Because if it was not there it would cause to much ultaviolet radation and that would kill us.

The ozone layer of Earth's atmosphere blocks most of the harmful ultraviolet radiation from the sun.

I cant really gove you an answer,but what I can give you is a way to a solution, that is you have to find the anglde that you relate to or peaks your interest. A good paper is one that people get drawn into because it reaches them ln some way.As for me WW11 to me, I think of the holocaust and the effect it had on the survivors, their families and those who stood by and did nothing until it was too late.