Awareness of unethical goods sold in supermarkets

We have government health warnings on cigarettes in order to allow the consumer to make an informed decision if they want to purchase this product, its about time we considered the health of our planet as well and make all products sold in supermarkets carry a relivant warning to inform the consumer of its impact on the environment to include the product itself and packaging together. To start with one ofthe biggest offenders to our planet....the plastic carrier bag.... we needlessly use billions of these, if they carried a sufficiant warning in huge letters on them highlighting thier danger to wildlife and thier general unethical and wasteful use of energy and resorces,im sure we would see a massive reduction in thier use, fewer people would be happy about being seen walking from the shops with  this stamped on the side for everyone to see, many people would then take thier reusable bags with them... the ones they like to be seen with, the ones with the pictures they have chosen and like on the side.

A warning on any product that causes harm to the planet is a consumers right to be informed just as much as if it causes harm to your health...
why are these warnings not in place?