Carrier bags ‘not eco-villains after all’
Unpublished Government research suggests the plastic carrier may not be an eco villain after all – but, whisper it, an unsung hero. Hated by environmentalists and shunned by shoppers, the disposable plastic bag is piling up in a shame-filled corner of retail history. But a draft report by the Environment Agency has found that ordinary polythene bags used by shops are actually greener than supposedly low impact choices.
LDPE/HDPE bags are, for each use, almost 200 times less damaging to the climate than cotton hold-alls favoured by environmentalists, and have less than one third of the Co2 emissions than paper bags which are given out by retailers such as Primark.
The findings suggest that, in order to balance out the tiny impact of each lightweight plastic bag, consumers would have to use the same cotton bag every working day for a year, or use paper bags at least thrice rather than sticking them in the bin or recycling.
Most paper bags are used only once and one study assumed cotton bags were used only 51 times before being discarded, making them – according to this new report – worse than single-use plastic bags.
However, despite being commissioned in 2005 and scheduled for publication in 2007, the research has not been released to the public.
Officially, the Environment Agency says the report, Life Cycle Assessment of Supermarket Carrier Bags, by Dr Chris Edwards and Jonna Meyhoff Fry, is still being peer reviewed. However it was submitted to the peer review process “more than a year ago”. Despite the long peer review the Environment Agency does not have a date for its publication, except to say that it will be soon.
The report set out to find out which of seven types of bags have the lowest environmental impact by assessing pollution caused by extraction of raw materials, production, transportation and disposal.
It found that an HDPE plastic bag would have a baseline global warming potential of 1.57 kg Co2 equivalent, falling to 1.4 kg Co2e if re-used once, the same as a paper bag used four times (1.38 kg Co2e).
A cotton bag would have to be re-used 171 times to emit a similar level, 1.57 kg Co2e.
The researchers concluded: “The Polythene carrier bag had the lowest environmental impacts of the single use options in nine of the 10 impact categories. The bag performed well because it was the lightest single use bag considered.”