It’s a strange comment on the attitude of modern Western governments to their electorates (or subjects, as I’m sure they would love to call us) that, whenever they want us to stop doing something, they impose a tax on whatever it is. It’s the attitude that brought us the congestion charge, the landfill tax and, from next year in Northern Ireland according to an environment news story in The Guardian, the plastic bag tax.

The theory goes that if people have to pay a tax on something, they’ll stop doing it. It seems to have some success – the same plastic bag tax coincided with a drop of 90% in bag consumption in the Republic since its introduction in 2002. I say ‘coincided’ rather than ‘resulted’: nobody can tell whether the change in behaviour was the result of the tax or whether the Irish people were in a frame of mind to address the issue of plastic bags clogging up the environment anyway, which was why they put up with the tax. The politicians in Northern Ireland, on the other hand, seem convinced it is their benevolent bestowment of tax regimes that bring about changes.

Alex Attwood, the Northern Ireland Executive’s Environment Minister, put it rather patronisingly thus when explaining that the tax would ‘only’ be 5p for the first year: “…I recognise that consumers will need time to change their behaviour and adjust to bringing their own bags when they shop. I therefore propose to discount the charge to 5p in the first year. This will ensure a phased approach to charging."

What that really means is that it will give the NI Executive the opportunity to get used to having several million pounds more to spend before the sum is halved by the effectiveness of the tax, only to have it raised to restore the shortfall.

That is the crux for governments: they are addicted to spending public money, so when a new source of revenue comes along they want to keep it. The success of these deterrence taxes is that they have to keep going up to replace the cost of their own success – if there is any. It’s an argument aired many times over the issue of tobacco and alcohol duty, which were originally introduced unashamedly to raise money for the monarch of the day.

Surely the way to stop people using too many plastic bags is to stop the supermarkets from providing them. The budget supermarkets have never provided bags; they offer boxes to those without their own bags. That brings me to my nostalgia bit. Decades ago people always had their own shopping bags. Older people still do; I remember my parents taking a ‘bag of bags’ with them well before it became fashionable. But where’s the revenue in that, I hear governments bleating.

Other environment news reveals that, ironically, it seems that when we take steps to reduce our carbon footprint by making processes more eco-friendly, we then use them more. If we convert to an electric car we drive it more; if we insulate our homes we turn up the heating. This process is known as ‘the rebound effect’. One study, quoted by Silvia Rowley in The Guardian, found that the rebound effect, together with a tendency to spend money saved on other carbon-producing activity, can result in up to 34% of the carbon saving being re-used.

Now I’ve dined out for years on the story of how I scored 114% in a statistics exam (thus proving that you should NEVER trust statistics), so I’m pretty confident when I say that what that 34% figure really shows is that 66% of the saving sticks. Some people are never satisfied!

Maybe we should make sure that, when we do ‘spend’ the carbon savings we’ve made, we do so in as eco-friendly way as possible. We could investigate the possibilities by perusing the Environment Directory on this site.