Easy labeling has been a recurring theme in the concepts. After repeatedly mistyping the word footprint, I thought of the Foodprint label. The label can be put on food items, and represents the carbon footprint of a product, calculated on the basis of what is needed to grow the product, packaging and transport.
The foodprint logo can be a sticker or printed version on the food or packaging itself, and can also be an indicator of a very simple app. Scan the food's label (QR code or otherwise) and get a red, orange or green Foodprint back, so you know what's the impact of that product.
This concept is not so much a concept in itself, as more of a building block that can be used in other concepts. Some of them already in the great collection, and others maybe to come. Feel free to use it as you see fit.