If a man makes a lot of money supporting a business that pollutes the environment, and then spends the money supporting environmentally focused charities, is he good or evil? What does philosophy say about this kind of behavior?
It's rare for philosophers to make ethical claims about men. There are different schools about how to discuss moral behaviour.
In virtue ethics there are right or wrong virtues.
In consequentialism there are right or wrong consequences.
In deontological ethics there are right or wrong intentions.
This is very simplified and there's also other schools. Since philosophers disagree about how to discuss ethics it's difficult to say anything about complicated questions like the one you asked. More information is needed. What is the virtues of this man? What is his intentions? And what is the sum of the consequences?
I think that most philosophers agree there can't be a final answer. There will always be a lack of information. We don't see an end to consequences and we can never dig deep enough into our "real" intentions and virtues.
If the polluter asks if he can "pay back" I think it's the wrong question in most ethical contexts. There are right or wrong things to do and that's the same for everyone.