Why could the formation of a hole in the ozone layer cause concern?

Because it can damage the protective layer in the earth's atmosphere, therefor causing a risk of high damage from meteorites and asteroids.

Explanation:

The formation of a hole in the ozone layer would cause concern because it increases the amount of ultraviolet rays that reach Earth and can harm it's inhabitants.

the electromagnetic energy from the sun arrives in the form of visible and invisible light.