How much carbon is used to create items that I purchase?

We need to get an understanding of how much carbon is used to create the product that I am purchasing.  For example , at present food has colour coding for how good food  is for you. I am suggesting items are coded that tells you how much energy used to create including production packaging ...transport...and we need to purchase below a certain level that has a carbon level that is sustainable...what is that.? I know there are sustainable products but is that sustainable in amount of carbon expended.?However need a way that supporting  developing nations and fairtrade products...

Encouraging people to understand how much energy produced to create product....