Anger over plastic bags is misplaced, says Jane Bickerstaffe in The Green Room this week. Their environmental impact is negligible, she argues, and taxing them can cause more serious damage.
The humble and much maligned thin plastic carrier bag is at least as much a household hero as the pantomime villain it is often (mis)cast to be.
Packaging has a tiny environmental impact compared with the impact of heating our homes and using private transport, let alone flying
A recent UK government-funded initiative to look at ways to reduce use of thin bags found that people don't want more re-usable "Bags for Life" - they already have plenty in their homes - they just forget to take them to the shops!
Surely, though, it's not that difficult if we are planning a shopping trip to remember to take our own bags.
We manage when we are on holiday in Italy or Spain, where the practice is more commonplace.
It might be different on ad-hoc trips, but still it is not necessary to always accept a new bag. One national UK pharmacy chain has trained its staff to ask customers whether they really need a bag.
All packaging (including carrier bags) has a tiny environmental impact compared with the impact of heating our homes and using private transport, let alone flying.
Putting a tax on carrier bags does nothing to help the environment. It simply adds costs and penalises those who can least afford to pay - the elderly and those without cars.
Another argument commonly directed against plastic bags is that they do not quickly degrade in landfill. These bags represent just 0.3% of household waste sent to landfill and the fact that they are relatively inert and stable is an advantage.
Biodegradable waste, on the other hand, such as potato peelings, some degradable plastics, junk mail and newspapers, does break down in landfill and releases greenhouse gases. This is why a European Landfill Directive has set targets to reduce the amount of biodegradable material landfilled.
However, a number of governments around the world are considering introducing, or have introduced, taxes or bans on plastic carrier bags. The reasons vary according to the country.
The Irish Government, for example, claimed that the sole purpose of taxing plastic bags was to solve a litter problem.
Has Ireland's plastic bag tax increased the use of lorries?
Yet two years after the introduction of the tax, plastic carrier bags still constituted 0.25% of litter according to the Irish Litter Monitoring Body.
In the UK, with no such tax, they were only 0.06% of litter, according to a survey commissioned by Incpen and carried out by Encams, the charity which runs the Keep Britain Tidy campaign.
In any case, there is no excuse for littering anything in countries where the authorities provide a waste management infrastructure.
In countries such as Rwanda and Bangladesh where plastic bags have been banned because they clog drains and exacerbate flooding, the problem arises because there is no such infrastructure.
In the short term, banning bags may be necessary to help reduce flooding, but the best solution is to manage waste properly and enable the public to dispose of all waste responsibly.
Re-used not recycled
According to the UK government's environment department, over 80% of plastic bags are re-used by British households.
Once a bag has completed its task of transporting purchases from shop to home, it becomes a bin liner, a disposable nappy bag, or something to carry muddy football boots in.
Bags represent just 0.3% of household waste sent to landfill and the fact that they are relatively inert and stable is an advantage
In practice, the tax in Ireland has actually had a negative effect on the environment.
Deprived of thin bags, people have had to buy tailor-made bags. Tesco reports selling 80% more pedal bin liners and SuperQuinn supermarket 84% more disposable nappy bags; these are thicker and use more resources.
Marks & Spencer reports using three times as many lorries to transport alternative bags to their Irish stores with a resulting rise in exhaust emissions and traffic nuisance.
So let's not be too hard on the thin plastic carrier bag. We can use it for its original purpose and then re-use it for lots of other things when we get it home.
Jane Bickerstaffe is director of Incpen, the Industry Council for Packaging and the Environment, in the UK. Incpen aims to analyse and minimise the environmental and social impacts of packaging.
The Green Room is a series of opinion pieces on environmental issues running weekly on the BBC News website.