The Environment Agency will argue today that carbon rationing is the fairest and most effective way for the UK to meet its legally binding targets to cut greenhouse gas emissions. The Agency’s chairman, Lord Smith, will propose at the organisation's annual conference in London that every citizen be provided with a "carbon account" and unique number that they submit when buying carbon-intensive items such as petrol, electricity or airline tickets. Individuals would then periodically receive statements that show the carbon impact of each purchase and how much of their annual ration has been used up. If they exceeded this ration,...