Given the information asymmetry between buyer and seller, the latter has an incentive to cheat by providing goods of lower quality or in smaller quantity than agreed. Of course, the buyers will eventually notice the deceit and stay away from such a market. The ancient Greeks found a clever solution to this problem: they established public institutions to improve and maintain market efficiency.
There is no denying that any developmental process that alters the composition of the global atmosphere and puts pressure on ecological and socio-economic systems, that are already under stress due to population and economic growth, is a threat to sustainability.