Some goods already carry the label but it’s only a few and participation is strictly voluntary at the moment. Now the government’s stepping in to standardize measurements and extend the plan to all manufacturers. Is it too much to dream that in a few years, when the hysteria’s reached a crescendo, some wise old progressive soul might float the idea of … “carbon rationing”? 100 credits a week; just present your card when you go to pay and the cashier will deduct the appropriate amount.

Won’t that be nice.

Plans have been unveiled to design a “carbon calculator” that could work out the quantity of greenhouse gases emitted by everything from the production of a pack of tomatoes to a car.

The Department for Environment, Food and Rural Affairs [Delfra] joined forces yesterday with the Carbon Trust, a Government advisory body, to try to agree how to measure greenhouse gases in the manufacturing process…

A spokesman for Defra said: “We need to look at cradle-to-grave emissions, whether it be a tomato, a CD or a car.”…

The carbon footprint of a beef steak, for instance, is likely to take into account the energy used to grow the wheat for the animal feed…

BSI British Standards will oversee the work and come up with a benchmark to avoid retailers and manufacturers trying to “out-green” each other. Nutritional labelling on food packaging has been undermined by disagreements between Tesco and Sainsbury’s and between different manufacturers.

Exit rhetorical question: They’re going to do this for everything sold at Live Earth, right down to the nine-dollar bottles of spring water, aren’t they?