While I think change has to come from both consumers and producers, this kind of gimmick (an interesting gimmick, but a gimmick nonetheless) puts too much of the burden on consumers and feels like tinkering around the edges of the real issues. It feeds into a model where the emitters don't take direct responsibility for their emissions, where it's easier to calculate, and pass the costs on down through the supply chain, as other commenters have noted.

It's rather like the successful campaign of companies to push the burden of disposable rubbish onto consumers instead of changing the system: https://blogs.scientificamerican.com/observations/more-recyc...