In a few years from now you will have another plastic card in your wallet - your carbon card. You will start the year with 1,000 points on it and each time you fill up your car, you put the card in a slot on the pump and it will deduct a few points.
Each time you buy an airline ticket, it will cost you a minimum of 100 points. If you fly regularly, you may have to buy more points through the carbon market - but since it is all in the cause of reducing greenhouse gas emissions you do not mind so much.
If this technology allowed you to "spend" your carbon allowance anonymously, it might only be massively inconvenient. But you can bet this government would make the credits fully traceable, providing yet another detailed window into your life.
The proponents of this scheme accept that citizens should be able to buy and sell carbon allowances. So why not just fold the system into a general emissions tax? This would be far more efficient and offer fewer opportunities for privacy invasion and social control. Oh — now I understand.