A new way of rating the environmental impact of supermarket foods has been unveiled by Oxford University academics. The method could help leading food companies better measure their climate impacts. However, improved estimates will require more accurate information on ingredient sourcing from producers, such as country of origin or agricultural production methods.
Researchers in the Livestock, Environment and People (LEAP) programme and Oxford Population Health at the University of Oxford, used publicly available information to estimate the environmental impact of 57,000 food products in the UK and Ireland, which make up the majority of foods and drinks for sale in UK supermarkets.
They looked at greenhouse gas emissions, land use, water stress, and eutrophication potential (when bodies of water become enriched with nutrients, often causing harmful algal blooms and ultimately killing other life). These four scores were combined into a single estimated composite environmental impact score per 100g of product.
More bad news for beef
Meat and dairy didn’t fare well in the study. Jerky, biltong, and other dried beef products, which typically have more than 100g of fresh meat per 100g of final product, often had the highest environmental impact. Products made of fruits, vegetables, sugar, and flour, such as soups, salads, bread and many breakfast cereals had the lowest. Meat alternatives had a fifth to less than a tenth of the environmental impact of meat-based equivalents.
There was also a link between nutrition and environmental impact. The more sustainable products tended to be more nutritious, though there were exceptions, such as sugary beverages, which have a low environmental impact and also score poorly for nutritional quality.
Enabling more environmentally sustainable food production
This is the first time a transparent and reproducible method has been developed to assess the environmental impacts of multi-ingredient products, the researchers claimed. This provides a first step towards enabling consumers, retailers, and policymakers to make informed decisions on the environmental impacts of food and drink products.
Such a solution is wanted by consumers and producers alike. A study by the UK's Food Standards Agency shows more than half of UK consumers want to make more sustainable decisions on the environmental impacts of foods. At the same time, food corporations are setting ambitious net zero greenhouse gas targets. But up to now there has been a lack of detailed environmental impact information on food and drink products – which would allow consumers and corporations to make more sustainable choices, claimed the researchers.
“This work is very exciting. For the first time, we have a transparent and comparable method for assessing the environmental footprint of multi-ingredient processed foods,” said Professor Peter Scarborough, Oxford Professor of Population Health. “These types of foods make up most of the supermarket shopping we do, but until now there was no way of directly comparing their impact on the environment. This work could support tools that help consumers make more environmentally sustainable food purchasing decisions. More importantly, it could prompt retailers and food manufacturers to reduce the environmental impact of the food supply thereby making it easier for all of us to have healthier, more sustainable diets.”
But the analysis omits ingredient sourcing information
Some poured scorn on the study’s findings, however, considering them as merely providing yet another stick with which to beat the increasingly maligned meat and dairy industry. “You couldn't actually make it up,” complained the farmer and conservationist Joe Stanley, an advocate for sustainability in food and farming, in a tweet. “Don't eat a natural, healthy, meat inclusive diet that humans have been eating for thousands of years, produced on grassland which sequesters carbon. Eat and drink the sugar/chemical filled, highly processed, factory/mass produced crap instead!”
The study’s lead author Dr Micheal Clarke was sympathetic to this criticism. The issue, he explained to FoodNavigator, was that the researchers did not identify ingredient sourcing, such as country of origin, as this was not available for most products. This data is needed to fully understand the impacts of different foods. What’s more, because portion sizes vary for different products, uncertainties remain in the total environmental impacts of products.
Producers rarely list quantities. While in the UK they are legally obliged to provide percentage values for certain ingredients, and ingredients are listed on packaging in order of size, the amount of every ingredient in a multi-ingredient food or drink product is usually known only to the manufacturer. The food product information in the Oxford University analysis therefore used foodDB, a University of Oxford research platform which collects information from the online stores of food retailers on a weekly basis. As such, producer-level environmental impact estimates were randomly and repeatedly selected to pair with the composition of each ingredient in each product.
“One of the limitations that we're dealing with is supply chain transparency,” revealed Dr Clarke, “so we have to make certain assumptions about where, for example, that beef is coming from.
“A lot of beef producers in the UK may be doing better than average and some are doing worse than average. You can produce beef slightly better, or much worse, but we can't account for that because we don't have information saying, for example, how the beef in this lasagne is produced. That's more of a supply chain transparency issue and until that's overcome and that information becomes more transparent for researchers, the public and corporations to use, then somebody's always going to have to make assumptions on where ingredients are is coming from.”
How to make use of environmental scores?
How will the information best be used? It should pave the way for more widespread of eco-labels, was the call from many, so that consumers and retailers can more easily and accurately compare the environmental impact of food and beverage products. But Clarke told us action was needed at the corporate level to reduce the environmental impact in supply chains.
He stressed the research is consequently only a first step towards providing information that could enable informed decision-making and called on the food industry to “help fill the gaps” to increase transparency the total environmental impacts of products.
“We hope that this is just the start and a steppingstone towards a much longer journey,” he said. “From what we're aware of, this is the first time someone has come up with a standardised the scores of the environmental impacts of a lot of different products. We still need to find how best to communicate this information effectively, in order to shift behaviour towards more sustainable outcomes. But assessing the impact of products is an important step forward.”
Reference
Environmental impact of 57,000 multi-ingredient processed foods revealed
Proceedings of the National Academy of Sciences
DOI: 10.1073/pnas.2120584119.
