What is caused by humans putting too much greenhouse gas into the atmosphere?
The increase in greenhouse gases emitted by humans is a main contributor to the hole in the ozone layer, global warming and thus climate change.
See these Socratic questions and answers for more information:
The role of greenhouse gases and global warming
The difference between global warming and the greenhouse effect
What role humans play in climate change
If the ozone layer is depleted, how will humans be affected?