The greenest living people that I know are rural dwelling African people that lead a subsistence agriculture life.
They live in wattle and daub houses made of mud, saplings and thatch. These houses will degrade back to their natural state (pile of mud and rotted sticks) within a few years if left unmaintained. Using saplings mean that the wood component is quickly regenerated new growth so the impact is very low.
These people hand-till all their own land and raise 90% of their own food by their own hands. They trade some for other products/services.
They don't have cars, running water, electricity, bank accounts, telephone or internet.
They catch their own fish (by hook and line) and raise some grass fed sheep and cattle. They have some chickens that are fed on scraps and that eat bugs (natural pest control).
Water mainly comes from springs (gathered by bucket).
They do use a small amount of kerosene for lighting.
So yes, it is possible to be very green and not have to be middle class or indulgent.
Written in August