[NeedMoreTea]

I'd be delighted if that were to happen, impractical though it might be. Only if every product and company had to do the same, including all their externalities. That would both incentivise and enable people to shop and invest wisely. Colour code and grade them just like EU energy efficiency labels - which were so successful in pushing to higher efficiency they had to re-rate them all.

Right now it's almost impossible to know the impact of what you buy, or which is better. Or how the impact of some produce available year round varies across the year. I know buying a lettuce in winter is going to have larger impact than in summer, but I have no way to quantify it.

It would also be an excellent starting point for building a carbon tax, that could slowly escalate to punitive.

[edejong]

There is complete accounting in the food chain. It is precisely known where your lettuce was grown, when and how it was transported, stored, frozen, thawed and placed in the supermarket. It is even known who's picking it up from the shelves and paying for it.

The only problem is: the general public knows nothing of this!

[NeedMoreTea]

I'm sure that's the case in most industries. They know what they buy, sell, who they outsource to etc. Lenovo and Apple know where their laptops were made, which bits and what raw materials or suppliers they used.

All we need is to derive the impact from each step, and some helpful way to present it. For presentation we know approaches that work. So it's really just requiring the carbon/impact accounting - and penalties for fraud. :)

Then we can decide if we're better off, environmentally, buying a Thinkpad, a Macbook, or a Mac Mini with LG monitor. Whether to pass on those out of season lettuces, or should really be concerned about something making more impact. All we can do right now is guess for just about everything.