UK Carbon Swipe-Card Plan

Following on my idea for an environmental rewards card, I read about a similar idea being undertaken in Britain.

Under the scheme, all UK citizens from the Queen down would be allocated an identical annual carbon allowance, stored as points on an electronic card similar to Air Miles or supermarket loyalty cards.

Points would be deducted at point of sale for every purchase of non-renewable energy. People who did not use their full allocation, such as families who do not own a car, would be able to sell their surplus carbon points into a central bank.

I am intrigued. I like the concept, but wonder how exactly it will work. The first thing I don't get is who forces you to actually swipe the card when you make a purchase? Will you not be able to buy gasoline (or any other product) if you don't have the card? Otherwise it seems like it is pretty easy just not to use the card and keep your points.

The second thing I am curious about is how they will actually calculate carbon. Is it just fuel you consume directly? Or will they try and calculate how much carbon was emitted to grow your food, build your computer or light the building of your doctors office? Seems like there is lots of carbon emitted indirectly from purchases and you should account for it.

I like putting the emphasis on the consumer to make the choices, but I wonder how well this system will work in practice. Definitely one to watch.

via The Guardian via TreeHugger