So yesterday Gordon Brown pledged to ban the plastic bag from Britain, and as you'd expect the Independent is very happy. The question I wonder is what they will replace them with? The two options on the table are reusable bags or paper bags (like they already use across much of America).
The problem with the first is that we already have reusable bags. They're called plastic bags. What's more, the assumption that we will all go to the supermarket and remember to take our bags is a bit weak. Sure, for a once a week shop perhaps we will, but what about the times we pop in because we suddenly remember we need something?
As for paper bags, it is worth remembering this. To produce a paper bag takes around five times the BTU (or joules if you're a metric nut) as it does to produce a plastic one. Virgin pulp is more often used than recycled pulp for strength purposes, so most new bags come from newly cut down trees which is... errr... bad for the environment right?
Then of course there is the pollution issue. Have you ever been near a paper mill? It stinks. That's because in order to produce paper products they have to use a vast number of chemcial pollutants that pump untold crap into the air as well as chemcial waste into the water supply (which is then cleaned out of course before we have to drink it). It's estimated that the air and water pollution of paper production vastly outstrips that of plastic production.
Of course, paper bags can be recycled, but then so can plastic bags. The advantage of plastic bag recycling is that you can make new plastic bags from old one. You can't do that with paper because the more you recycle the faster the quality of the paper as well its strength degrades. Buy some recycled toilet roll for someone with hemerroids and ask them to compare it with Andrex if you don't believe me.
What about the energy cost of recycling paper versus plastic? Well a paper bag will require around 1000 times the BTU as plastic bag will to recycle. The energy efficiency cost in recycling paper bags is around 90% more than that of plastic as a result.
"But what about degradability!" I hear you cry. What about it? Paper bags and plastic bags are both degradable. Modern polymers have a lifetime of about 18 months in landfill, and they take up less space than paper bags do. Of course, paper is recycled more than plastic, so this point could be said to be moot.
The long and short of it seems to be this. Plastic bags are less damaging to the environment in total energy and pollution costs than paper ones. They don't require deforestation to make; they don't require increased air and water pollution in their production; their landfill cost is less; and their recycle energy usage is more efficient.
Instead of banning them - which sounds ever so green because they are "man made" and thus seem unnatural to the paper equivalent that comes from the earth - perhaps we should be sending out a stronger message that people either (a) reuse them, or (b) recycle them. Whilst we're at it, why don't we ban paper bags instead, they're the real killers of the planet surely?