Is self publishing the way forward for sustainable publishing?

For several years I sorted books in a charity shop, and now help run a bookstall at a yearly Green Fair. In both situations there%u2019s one kind of book that rarely sells: hefty hardback novels, often crime, that have presumably been given as a present, read once (if at all) then donated. In second-hand contexts, very few people want books like these; paperbacks are far more popular. Most of those donated will end up in landfill. What a waste! - of the paper used to make the book, the warehouse storage, the fuel for transportation. And, Green Fair volunteers might add, of the effort of lugging heavy boxes to the stall and re-packing unwanted copies at the end of the day.