The great plastic bag con.

Just recently the Prime Minister was in the news talking about introducing legislation to reduce single use plastic bags (http://news.bbc.co.uk/1/hi/uk_politics/7101075.stm). Now I may be a cynic but I suspect he's more interested in the tax other countries have introduced on plastic bags rather than any real green motive.
Ireland has introduced such a tax and now charges 15 cents per bag. In the UK the tax would probably be 10p.

Now, admittedly the Irish tax has slashed the number of plastic bags used dramatically - by 277 million says the Irish government, but it's also raised 2½ million pounds in tax. In the UK if a similar pattern was followed it would raise 70 million pounds in tax. Now this is a drop in the ocean as far as UK tax is concerned - it would cost each of us in the UK just over £1.00 per year and would save 8.4 billion plastic bags each year! That would probably make our environment a lot tidier. But would it actually be much use as a way of combatting global warming?

Let's work it out:
On average each of us in the UK uses 150 bags each per year.
Each one weighs 8 grams - that's 1.2 Kg of plastic which if burnt would produce 3.7Kg of carbon dioxide.
Now that's not quite a true figure because a) CO2 is produced in the manufacturing process and transport of the bags b) many of the bags are disposed of in landfills where they do not decompose but instead remove carbon from our environment.
Let's take a worst case scenario and assume that all the bags are incinerated and that an equal amount of CO2 is produced in the bag manufacture. That would mean each of us is producing 7.5Kg of CO2 each year by just using plastic bags.

Now, let's compare that with other things.
An average motorist in the UK uses 1143 litres of fuel per year and produces 2700Kg of CO2 from it. By reducing his car use by just 0.3% (3/1000ths) each year Mr Average would save his 7.5Kg of CO2
If we all bought 0.3% more local products rather than foreign imports we could save ten times as much CO2 (from transport production of CO2) as we would use with plastic bags.
If we each used 900 fewer sheets of paper each year then that would save the same amount of CO2 as we use in plastic bags - That's equivalent to a magazine per month, two books less per year or just ten fewer newspapers. (Before you say it using recycled paper actually produces more CO2 since there are extra processing costs)

In fact we could produce less CO2 than we use in plastic bags by:

• fitting a single low wattage bulb as a replacement
• turning down the thermostat by just 0.3 degrees (wouldn't it be nice if thermostats were that accurate?)
• fitting an extra 1cm of loft insulation (of course you can't buy insulation that thin so you'll save much more than this)
  
• switching the TV off at night rather than leaving it on standby
• recycling glass bottles
• recycling aluminium cans
• unplugging your mobile phone charger when not using it
• fixing a sheet of aluminium foil to the wall behind your radiators (use Blue-tac).

There are lots of other ways - try a search for 'reducing greenhouse gasses' (Watch out for that misleading 'recycle paper' though)

Now what does this mean.

• Putting a tax on plastic bags and pretending to be 'green' is foolish. It's easy to say, makes the government a little extra cash and achieves very little other than tidying the environment.
• Shops like the idea. Those plastic bags cost them about 2p each. I find it interesting that firms like Tesco offer a 'green point' worth 1p every time you reuse a large bag which holds at least twice the amount you put in single use bags. (2 x 2p = 4p, less 1p for a green point = 3 p extra profit)
  
• There are far more effective ways of reducing greenhouse gases and almost all of them save you money.
  

Having said all that - Lets get rid of the bags but only because of the litter problem they create not because of the greenhouse problem.