When carbon footprinting, the allocation of carbon between different companies is a tricky issue as we’ve discussed before. Does the carbon produced by a gas-fired power station ‘belong’ to the power generator, or the power consumer?

Well, the British Standard Institute (BSi) has just released a draft of their forthcoming PAS 2050 carbon footprinting standard and it is interesting to see how they approach the problem. The standard is based roughly on the Life Cycle Assessment (LCA) methodology to estimating the environmental impact of products, rather than taking a company by company approach. This means that if your company is part of a supply chain, your products’ embodied carbon will count against you and your customers’ products, rather than being divvied up between you. So in the example above, carbon emissions from the power station would count against the generator and the consumer. This is a sensible approach as long as everyone understands there is double counting involved – and no-one adds them together to get a ‘total’.

Many of the criticisms I’ve levelled at LCA apply here too. In particular, it will be interesting to see how rival companies’ footprints compare and what assumptions they use to get there. I’m sure there will be some robust debates!