The UK’s leading supermarkets have cut the number of single-use carrier bags used by 48% compared to 2006 levels, the Waste & Resources Action Programme announced in July. The achievement falls just short of a voluntary agreement to cut the number of single-use carry bags handed out by 50% by spring 2009. But what kind of achievement is this?

According to reports yesterday, the Welsh Assembly is the latest government to consider outlawing the free distribution of plastic bags in shops. Jane Davidson, the Welsh environment minister, said that many shoppers were still failing “to embrace the environmental message” despite a raft of measures by supermarkets and other retailers to encourage us to use fewer of them. One solution now being given serious consideration by the Welsh authorities is the introduction of a 15p levy on every plastic or paper bag handed out to shoppers in the principality.

In Ireland a so called “Plastax” of 15 cents per bag saw single use plastic bag drop overnight and a billion fewer bags being used in the year since the tax.

But the scheme has had its critics. While it was true that the tax led to a dramatic drop in the number of bags being handed out in shops, it also triggered a 400% increase in the number of bin liners and black refuse bags being purchased. The tax also encouraged an increased reliance on paper bags which, according to a number of life-cycle analysis studies that have compared the environmental performance of various types of bags, require more energy to manufacture and release more greenhouse gases when degrading following their disposal.

The target of the criticism is that we are either largely wasting our time pursuing such tactics in attempting to eradicate plastic bags, or that we are allowing ourselves to be distracted by what is, relatively speaking, a fairly minor environmental woe. James Lovelock, the climate scientist, has referred to the current obsession with plastic bags as “rearranging the deckchairs on the Titanic”.

Patting ourselves on the back about how few plastic bags we each now use allows us to ignore far more pressing environmental issues such as, say, climate change, overpopulation, rapid species extinction and the depletion of resources such as fresh water. Today’s war on plastic bags is certainly worth fighting, but not if it is at the expense of these other concerns.