Not my OC but what I've believed for years: there's no conflict between reducing your own environmental impact and holding corporations responsible. We hold corps responsible for the environment by creating a societal ethos of environmental responsibility that forces corporations to serve the people's needs or go bankrupt or be outlawed. And anyone who feels that kind of ethos will reduce their own environmental impact because it's the right thing to do.
Thoughts?
Their "own interests"
this is a key phrase here for me.
Once a person has a modest amount; is it in their interests to eat more and get fat, or to live in a place where other people share in having a modest amount, or, at least have a fair oppotunity to get a modest amount.
A person's morality will influence the scope of their concept of "own interests".
And therefore how much they want beyond meeting their "own basic needs" before they start caring more about neighbours with unfulfilled "basic needs".