Wednesday, 8 June 2011

How Plastic Bags Will Save The Planet

A couple of years ago a bandwagon started rolling through the UK.  Led by newspapers, and with the supermarkets and the government as the main passengers, a large proportion of the public jumped on board.  The target of this bandwagon was the humble plastic bag, provided for free by almost every shop in the country.

Plastic bags, you see, are evil.  They come from oil, and as we all know we should be using less of that.  Plus they choke turtles and strangle swans.

So shops started discouraging their use - customers were charged for them, asked if they really needed one, and offered bigger, tougher reusable bags.  But I think we've missed a trick here.

We need to look at what the evils actually are.  Let's take the turtles and swans for starters.  Plastic bags don't have to harm them.  I've got a bunch of them in the cupboard above the cooker and I've never discovered a dead swan in there.  It's not the bags themselves that cause the problem, it's their disposal.  Jamie, our venerable 16 year old Jack Russell once got into the Christmas chocolate and ended up with some serious kidney problems for his trouble, but that's not Cadbury's fault, it was ours for leaving it in his reach.  Wildlife deaths are a littering problem, not a plastic bag problem.

So is using oil an evil?  Well, this is where things get interesting.  You can do lots of things with oil:

  1. Leave it in the ground.
  2. Turn it into fuel and burn it.
  3. Turn it into plastics.
Option one is clearly the most environmentally friendly, but I think I can suggest that's a fairly unlikely outcome.  The second is probably the worst as far as things go - if the anthropogenic global warming theories are correct then this option is the one causing most of the problems.  That leaves the third option, turning it into plastics.

As we all know, plastic doesn't break down easily.  Hundreds of years is the number you'll hear bandied around - but what's wrong with that?  It means your supermarket carrier bag, if disposed of in landfill, will sit there for centuries, doing precisely nothing.  It won't break into carbon compounds and interfere with atmospheric chemistry, it will just be in the ground.  It's a very roundabout and inefficient way of doing option one, leaving the oil in the ground in the first place.  Plus, once oil becomes scarce enough, mining landfill for plastics will become profitable, and cheaper than drilling kilometres under the ocean for the raw material.

So we've got two reasonable options open to us: use the oil for fuel, or use it for plastics.  As far as I can see, the environmentally friendly option is to go for plastics.  Lots of them.  So many that when we run out of oil we've got something to show for it: plastic bags galore.  A little more atmospheric carbon is slightly less useful to the average person regardless of environmental effects, plastic mines on the other hand...well if you want to be cynical about it, there's money in plastic mines.

What about the people who need fuel, which is most of us?  Well, we're hideously bad at using it.  We burn oil in car engines, which are horribly inefficient, only around 20% of the energy in the fuel actually gets used for something practical (unless you regularly cook steak on your engine casing).  Burn it in a power station on the other hand, and you get around 33%.  Use that to charge fuel cells and you've got a bit more bang for your buck, and some leftover oil to turn into useful and environmentally friendly plastic bags.  In time, of course, we'll run out of oil and be forced to find alternatives - why shouldn't we be doing that sooner rather than later?  Use plastic bags and bring the future a little closer.

And plastic itself can be used for transport - paragliders for example, even small ones...


  1. Or you could reuse the bag and not take a new one every single time you buy something?

  2. Exactly my point - oil turned into plastic is re-usable, over and over again. Get the free bag, use it a hundred times, then reuse it. Recycling plastics is energy intensive, absolutely, but it's still better than just burning the raw material. Wood is a good comparison - burn it and you get heat, gas and ash. Make a wooden house...well, then you can turn it into wooden planks when it falls apart, and then sticks, and then toothpicks...eventually you burn it, yes, but not until you've actually used it for something...ideally two or three things.

    Thanks for the comment and interest, I don't get many of them :)