part 26 Oct 2011 22:54
The first commercial plastic was developed in the 19th century. That first plastic, called Parkesine, after its English inventor Alexander Parkes, was in fact made from biological sources - gun cotton (a mixture of natural fibre and nitric acid) and castor oil. But oil-based plastics soon came to dominate.
The world is now hugely reliant on oil-based plastic. They are strong, light weight and until recently, quite cheap. Their uses now range from the shopping bag, packaging and children’s toys to computer casings and car parts.
About 4% of the world’s oil production is converted into plastic, and that is one of the drawbacks. Oil is increasingly expensive, and the production of one kilogramme of plastic requires 20 kilowatt hours of energy – more than is needed to make an equivalent weight of steel.
So plastic production leaves a large carbon footprint. But the problem that attracts most attention is plastic’s indestructibility. Once its useful life is over, how do we get rid of it? According to a recent research paper by Chris Goodall of Carbon Commmentary, 5% of the world’s cumulative output of plastic since 1945 has ended up in the oceans, killing marine creatures that try to eat it.