Here is an article by Daniel Brousson of Onya Bags about the evils of all those plastic supermarket carrier bags.

How Many We Use

Plastic bag consumption from the nine major supermarkets, equates to an estimated annual total of around 17½ billion plastic bags. That’s enough plastic to cover an area greater than London, Liverpool, Manchester, Newcastle and West Yorkshire put together. The whole of England would be covered in just over 21 years. An average family accumulates 60 plastic bags in only four trips to the grocery store.

Each year, humanity gets through something like a trillion carrier bags, which together weigh approximately 5m tonnes and use about 50m barrels of oil to produce.

Who Cares?

B&Q asked more than 12,000 people across the UK for their views on, and use, of plastic bags. The answers showed:
47 per cent of those asked had more than 20 bags at home, and 9 per cent up to 80
40 per cent felt guilty at not re-using more of the bags they had
73 per cent were annoyed at neighbourhood litter caused by plastic bags
46 per cent took home up to 10 bags with their shopping each week.

Lifespan!

A person’s use of a plastic checkout bag can be measured in minutes – however long it takes to travel from the shop to their homes. Plastic bags however can take between 15 – 1000 years to breakdown in the environment.

Where Do They Go?

Nearly all disposed plastic bags end up increasing the waste amounts in landfill sites. This is not only stretching resources affecting local councils and increasing council taxes, but the eventual disposal of the plastic shopping bags thrown away is costing more and more in terms of taxes every year and it is becoming a genuine danger. Babies born within 2km of a landfill site are more likely to have birth defects than babies born elsewhere. Babies born within 3km of landfill sites taking hazardous waste are 40 per cent more likely to be born with chromosomal anomalies, such as Downs syndrome.

Where Else Do They Go?

OCEANS Globally, an estimated one million birds and 100,000 marine mammals and sea turtles die every year from entanglement in, or ingestion of, plastics. When the dead animals decay the plastic bags are freed to again be re-ingested by other animals for years to come. For example: A Minke whale stranded on a beach in Normandy was found to have 800g of plastic bags and packaging within its stomach. Amongst the identifiable litter were 1 English plastic and foil crisp packet, 2 English supermarket bags, 7 coloured dustbin fragments, 7 transparent plastic bags and 1 food container.

ON LAND In many countries discarded bags fill with rainwater and become breeding grounds for malaria-carrying mosquitoes. In Uganda, a child was killed when floods swept a slum after bags had blocked a drainage system. Livestock are also affected; a farmer in Australia carried out an autopsy on a dead calf and found 8 plastic bags in its stomach.

Litter

Not all litter is deliberate as 47per cent of wind-borne litter escaping from landfill is plastic; much of this is plastic bags.

Recycling

Only one in every 200 is recycled; the other 199 take up to 1,000 years to degrade.

Nuisance

In many council areas, plastic bags are widely considered to be the main contaminant of kerbside recycling

Whose Cost?

The average household spends £470 a year on packaging - one-sixth of its total food budget. An analysis of a typical Tesco or Asda shopping basket, carried out by the National Farmers Union, found that only 26 per cent of the cost is accounted for by food; the rest is packaging, processing, transport, store overheads, advertising and supermarket mark up.

Energy

The amount of petrol used to make one plastic bag would drive a car about 115 meters. The 17 ½ billion plastic checkout bags which are used a year are enough to drive a car 2.1 billion miles or nearly 54,000 times round the world, the equivalent to 10 roundtrips to the sun.

Do Your Bit

If you throw away four fewer plastic bags every week, you’ll save 4,160 bags from ending up in landfill sites over 20 years.

The Tide Is Turning

At least 40 countries or states are now known to have banned them or taken action to restrict their use. The movement began in the 1980s in Dhaka, Bangladesh, where millions of plastic bags were found to be clogging drains in the monsoons, causing terrible flooding. The citys 26 major plastic bag makers complained bitterly at proposals to outlaw them, but in March 2002 Bangladesh became the first country to ban them outright.
The case was taken up in Himachal Pradesh, in northern India, where plastic bags not only caused floods but were widely blamed for killing foraging cows. In August 2003, the state government banned them - on pain of seven years in prison or a 100,000 rupee fine (£1,250). Similar laws now apply in Mumbai, Maharashtra, Sikkim, Goa, Kerala and Karnatak states.
Meanwhile, Taiwan has begun to prohibit not only plastic bags, but also disposable plastic plates, cups and cutlery used by fast-food vendors. Spurred by the threat of fines of up to TW$9,000 (£152), the result has been a 70% reduction in the use of plastic bags, and a 25% cut in the volume of waste going to landfill.

Kenya is expected to ban them, after Wangari Mathaai, the 2004 Nobel peace prizewinner, linked plastic bag litter with malaria. When discarded, the bags can fill with rainwater, offering ideal breeding grounds for the malaria-carrying mosquitoes. South Africa, Rwanda and the self-declared Republic of Somaliland have all banned the flimsiest bags completely.

Since March 2002 Ireland, through a government tax initiative, has reduced its checkout plastic bag use by 90%. The Irish government claims a 95% reduction in bag use from its 2001 peak of 1.2bn bags a year, and says that bags made up 5% of litter before the duty but just 0.3% today. The tax also raises some €10m (£7m) a year for an environment fund, and enjoys wide public support.

A year ago, B&Q, which had been giving out 7m carrier bags a year in Scotland, introduced a 5p-per-bag charge in Scottish stores that may be adopted UK-wide. The result? An 82% fall in consumption, and a cash windfall for Keep Scotland Beautiful. Significantly, 70% of customers are "very happy" with the scheme, with only 1.8% "very unhappy".

Many countries, states and cities have also introduced either full bans or government taxes and levies in order to reduce plastic bag consumption, including: Denmark, Italy, South Africa, Singapore, Australia, India, Shanghai, Japan, Hong Kong, Switzerland, Tasmania, Mumbai

Plastic Bag Slag

In Ireland they are known as “witches’ knickers”
The Alaskans call them “landfill snowbirds”
In China they are “white pollution”
And South Africa has dubbed them its national flower.