Prof Alan McKinnon writes that it remains very difficult to measure emissions at a product level; Colin Challen believes that politicians have to be much more upfront about the changes we need to make
In reviving the idea of giving everyone a personal carbon allowance (PCA), Polly Toynbee’s article (We need radical policies to reach net zero. Here’s a fairer way to do them, 2 November) fails to mention the practicalities of carbon footprinting every product and service that people buy. Despite major advances in carbon auditing since a PCA system was originally advocated, it remains very difficult to measure emissions at a product level, particularly in the case of manufactured goods passing through complex global supply networks.
Also, for a PCA system to gain public confidence and legal endorsement, the carbon labelling of consumer purchases would have to be independently verified to ensure that suppliers did not under-report emissions to gain market share. This would add an extra layer of cost and bureaucracy. In an article 14 years ago (Can shopping save the planet, 17 September 2007), Marc Lynas said: “To figure out a carbon label for every product on the shelf would be a task of labyrinthine complexity and monumental cost.” Regrettably, this is still largely the case.
Prof Alan McKinnon
Kühne Logistics University