Experts have criticised Morrisons’ decision to switch from plastic to paper bags for fruit and vegetables, branding it a retrograde step for efforts to tackle climate change.
The Environment Agency found that paper carrier bags, across their lifecycle of production, use and disposal, had a greater global-warming impact than plastic ones. The agency’s study found paper ones were only better than plastic if they were used four or more times, but that was unlikely due to durability of paper bags.
While the research was published seven years ago, the government’s top waste and recycling advisers, Wrap, said the findings were still relevant today.
Chris Goodall, an author and environmental expert, said: “This is a retrograde step, moving back to paper.”
He agreed the impact of plastic pollution on marine life was very serious, but said: “Most of the plastic in the sea comes from a small number of rivers, it does not come from me buying green beans in Morrisons.”
Compared to using plastic bags for loose fruit and vegetable, paper bags were a backwards step in climate and energy use terms, Goodall said. One reason for the greater climate impact is that using paper will lessen the life expectancy of produce, he argued, leading to more food waste in landfill, where it generates methane, a powerful greenhouse gas.
However, Friends of the Earth said that it welcomed Morrisons’ switch and that green issues other than climate change should be factored in.
Julian Kirby, a campaigner at the group, said: “The thing about climate change is because it’s such a huge worry it has eclipsed other very serious environmental and health concerns, and that would include … pollution.
“With a paper bag, if it escapes into the environment it will biodegrade very soon. That is not the case with a plastic one.”
The supermarket appeared aware of the trade-off, saying it had weighed the environmental impact of paper against the potential pollution from plastic.
“We have listened to customers and they are telling us that the overuse of plastic is the most important environmental issue for us to deal with,” a spokesperson said.