Simon Miller Principal consultant, Best Foot Forward
Sir; The environmental impact of plastic bags is abundantly evident as unsightly litter on the branches of trees or blocking the digestive tracts of marine animals. But with the need to address climate change impacts, where do plastic bags sit in the context of greenhouse gas emissions? Best Foot Forward has calculated the emissions from producing a typical lightweight plastic bag at 19.8g. Compare this figure to the carbon label on Walkers crisps, at 75g, or Cadbury Dairy Milk, at 169g, and emissions from single-bag manufacture are relatively low. For 17 billion bags, the number used in the UK, total emissions are more than 330,000 tonnes but this is still only equivalent to about 0.05% of annual emissions from the UK's population. Bearing in mind the 80% emissions reductions target of the Stern Review, banging a green drum about reducing plastic bags may be over-egging the sustainability case.