It collected hundreds of pieces of supermarket data, including GHG emissions, plastic use, and food waste, both from their published reports and by asking the companies directly. It then analysed this data to compare the sustainability of the UK’s eleven biggest supermarket chains. Lidl scored highly for its low greenhouse gas (GHG) emissions and targets, while Waitrose did consistently well across all the categories looked at.
But Iceland took aim at the ‘completely flawed’ methodology used by the rankings. Iceland finished at the bottom of the rankings, performing worst on greenhouse gas emissions by some margin. The report said this may be due to the high proportion of frozen food it sells; it takes a lot of energy to keep products cold throughout the supply chain, from manufacturing to warehouses, stores, and delivery vehicles. It does, however, buy 100% renewable electricity for its UK sites. Iceland also uses the most plastic relative to the number of items sold, and received a relatively average score for food waste, resulting in a total score of just 29% overall.
Richard Walker, Managing Director at Iceland said: “Their calculation of carbon intensity grossly misrepresents Iceland because it is based on retail spend rather than sales volumes, penalising supermarkets that sell at low prices. Their calculation of plastic intensity is equally incorrect, and bears no relation to our own audited and published data on plastic usage, which is used to calculate the packaging taxes we pay.”
He added: “Iceland is committed to total transparency in regularly publishing audited data on its plastic consumption, carbon usage and food waste. We have taken a global lead in committing to plastic neutrality, the removal of plastic packaging from our own label range, and achieving net zero carbon emissions from all our operations by 2040. We are proud of our progress towards these challenging goals and are confident that our long-established Doing It Right culture will allow us to demonstrate continued transparent progress in sustainability in the years ahead."
Sharing top spot in the sustainability rankings, both with a score of 74%, were no-frills discounter Lidl and high-end grocer Waitrose. Lidl impressed with its low GHG emissions intensity – how many tonnes of carbon dioxide equivalent it emits per million pounds of revenue – and its aim to become carbon neutral this year. It also scored well on plastics, with a high proportion of its own-brand plastic being easily recyclable, although it did less well when it comes to food waste. Waitrose scored well across the board, with reasonable GHG and food waste scores, and it uses the least plastic compared to the number of items sold, measured as tonnes of plastic placed onto the market per million packs of groceries sold. Asda and Sainsbury’s were tied in third place, three percentage point behind the leaders.
Supermarkets have a big impact on the environment
“We know that the biggest issues for shoppers are the use of plastic packaging and the impact of food waste, while experts generally agree that greenhouse gas emissions pose the greatest global environmental threat,” it said. “We looked at all three issues to see exactly how the supermarkets compare. We weighted GHG emissions as 50% of a company’s total score. Food waste and plastic usage make up 25% each of the total.”
Which? said the sheer size and dominance of the big supermarkets means they have a big impact on the environment, through powering their shops and refrigerators, operating delivery vans and depots, packaging their products and handling their waste.
But no data on the impact of the products sold
While no supermarket excelled in every metric, there were clear front runners in individual categories, suggesting that all supermarkets have room for improvement, the researchers said. Aldi and Lidl achieved the lowest GHG emissions intensity, but Lidl topped our table due to its ambitious target to reach net zero for its operational emissions in 2022. Its emissions are 73% lower than Iceland’s, relative to sales revenue. The Co-op topped the plastic rankings, with 'outstanding' levels of recyclability. Waitrose recorded the lowest plastic intensity (ie. how much it uses compared to the number of items sold), putting it second overall on plastic. Ocado came top of the food waste table, with the best food waste intensity by some way. In contrast, the Co-op, Aldi and Lidl waste more than twenty times as much food as Ocado, proportional to their food sales, the report claimed.
While supermarket businesses are responsible for their own emissions, plastic and food waste, the products they sell also have big environmental impacts, whether it’s carbon emissions from shipping them across the world or issues such as deforestation, pollution, and water use in their farming and production. “Unfortunately, the supermarkets don’t yet report comprehensively on all of these measures for the products they stock, so we couldn’t compare them on these issues,” said Which?