Oxford scientists have analysed 57,000 multi-ingredient products - but the study has faced criticism

Everything  we buy has an impact on the planet. The question for food businesses is how that impact can be measured, analysed, and compared to help drive a more sustainable food system.

Last week, a new study from Oxford University took a step towards answering that question with a new analysis of the environmental impact of 57,000 multi-ingredient products in British supermarkets. With both business and consumers more eager to make environmentally conscious than ever, it is the exact type of academic research that many will rely upon to  make more sustainable decisions.

Until now, the only peer-reviewed study to compare the environmental impacts of food looked at basic commodities such as fruits, wheat, and beef. Co-authored by Joseph Poore Thomas Nemecek and published in Science, it looked at the environmental impacts of nearly 40,000 farms, and 1,600 processors, retailers, packaging types.

While it is the most comprehensive study of its type to state, it is sometimes criticised – most often by the meat lobby - for not adequately differentiating between different farming systems for each commodity. The new Oxford study, published in the journal PNAS, has faced similar comments, and lead author Michael Clarke recognises it’s a limitation.

“The reason we didn’t worry about that is because either way, you’d have to make assumptions. Even if you know it’s British beef, you’re still making really big assumptions in terms of: is this good British beef? Is it bad British beef? Somewhere in between?”

While Clarke recognises a more granular analysis “absolutely needs to be incorporated” in the future, “functionally, nobody’s going to be able to do that until that information is actually provided. And right now it’s not.”

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The considerations around British beef are ultimately a minor question in a study of 57k products, but the example does serve to illustrate the major data limitations facing any effort to calculate food’s impact.

The Oxford study, for example, relies on product ingredient lists scraped off supermarket websites, a clear limiting factor given the lack of sourcing information these provide. It’s a common problem facing any similar analysis.

“There is a massive data participation problem when it comes to measuring food’s impact,” says Cliona Howie, CEO of Foundation Earth, an eco-labelling scheme working with businesses such as  PepsiCo, Nestle, and Unilever.

Howie argues all actors in the supply chain will have to be more transparent with sourcing data if a genuinely comprehensive analysis of food’s impact can ever occur. As it stands, however, there is a lack of incentive for many to do so. “That data exists somewhere. We just need to start identifying what those incentives should be.”

At Oxford, Michael Clarke says the team is considering offering companies the opportunity to tailor their new analysis using by providing their own company’s sourcing data. This would not necessarily be so they could brandish their credentials on pack, he says, but simply help drive more sustainable decisions behind the scenes.

Some companies are seemingly interested. Clarke says a number of retailers, caterers, and restaurants have been in touch and are “curious to see what type of information I have that could be used to start moving towards more sustainable outcomes.”

As it stands, however, the scope of these outcomes will arguably be limited. Last week’s study focused on just four indicators - greenhouse gas emissions, land use, water stress, and eutrophication potential – again, due to the vast data limitations on other metrics. This is not only a flaw in any analysis, but risks ignoring what is actually most important to customers. 

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In customer research by Impact Score, an app that rates the sustainability credentials of over 280,000 supermarket products, carbon emissions came seventh, behind recycling, nutrition, animal welfare, and a handful of others, says co-founder Ian Yates.

“I know why we’re all focusing on CO2 and emissions, but the consumer hasn’t yet got to that stage. There’s some more education that they need to have before we can start putting solely stuff around emission and co2 out.”

Therefore when it comes to potentially giving an overall eco-scores for a single product, Yates warns against an oversimplification that provides shoppers with a single number based on a range of metrics. “Everybody thinks sustainability is something a little bit different and they want to make their own judgement call, rather than have us tell them.”

The reality is that whatever method a study like this uses it will face immense scrutiny. Given winners and losers are inevitable, finding a consensus behind any one system is going to be hard to reach. Perhaps the most important right now is that the knowledge keeps evolving, ensuring each step forward is based on  independence and trust.

As Michael Clarke says, “We know there are limitations. But this is a starting point towards something that’s hopefully a little bit better.”