There are very good reasons to be good custodians and stewards of the environment personally when we can afford to do so. I got rid of my car, got a bike, and walk or take public transport wherever I can. It has definitely improved my quality of life too. It won't save the world, but keeps me healthier, and is easier on my conscience.

Although, I realise I'm privileged that I live somewhere that has almost everything I need within walking distance. In the past I've lived places it would have been impractical or even impossible to give up my car. At least without other systems around me changing substantially (which made me aware of how dysfunctional the system can be, how dangerous it is, and the need to change it).