Every food choice has an effect on global biodiversity, according to researchers at the University of Cambridge’s Department of Zoology. Dr. Ball, a postdoctoral researcher in the Conservation Science Group, explained that producing animal-based foods such as beef requires much more land than plant-based proteins like beans or lentils, resulting in greater displacement of natural habitats and higher risks for species survival.
Ball pointed out that many popular foods consumed in Britain—including coffee, chocolate, and bananas—are grown in tropical regions with high biodiversity. Converting these areas to farmland can have significant consequences for local species. Furthermore, the impact of a specific crop on extinction risk can vary greatly depending on where it is grown. For example, Ball noted: “The coffee you choose to buy can really impact the likelihood of species going extinct," adding that differences in yields between coffee varieties also play a role.
Dr Alison Eyres, another postdoctoral researcher at Cambridge’s Conservation Science Group, used a new metric called LIFE to map changes in terrestrial species extinction probability under two scenarios: complete conversion of natural habitat to farmland and full restoration of farmland back to its natural state. While neither scenario is likely soon, Eyres said the maps reveal uneven impacts across regions and highlight the importance of preserving existing habitats over restoring damaged ones: “Although land restoration is important, the LIFE maps show the greater importance of preserving existing natural habitats to protect biodiversity, which can have bigger global-scale impacts than restoring areas we’ve already damaged.”
The LIFE metric takes into account both vulnerable and currently stable species and forecasts impacts over a 100-year period. It allows users to assess effects across different scales—from half a square kilometre up to more than 1,000 square kilometres.
Ball collaborated with Dr Jonathan Green from the Stockholm Environment Institute and the Joint Nature Conservation Committee (JNCC) to integrate national consumption data for 140 food types with the LIFE metric. This effort has made it possible for UK policymakers to measure how trade and agricultural policies affect global extinction risks—a first for any country.
"When it comes to decisions about producing food it’s not enough to focus on one country in isolation," Ball said. "We have a UK agricultural policy that incentivises farmers to set aside more land for nature, and reduce food production. But if that means we’re making up the shortfall by relying on imports from more biodiverse places, it could cause far more damage to the species on our planet in the long run."
According to their findings, most of Britain’s “extinction footprint” comes from imported foods rather than domestic production. For instance, beef imported from Australia or New Zealand poses thirty- to forty-fold higher extinction risks compared with beef produced locally.
Ball suggests that dietary shifts—such as eating less meat and fewer luxury crops like chocolate or coffee—could help free up land for restoration efforts and prevent hundreds of extinctions worldwide.
By combining LIFE with economic data on trade flows or specific businesses’ sourcing practices, conservation groups are now able to prioritize sites for protection more effectively and analyze their own impact using straightforward calculations rather than complex analyses requiring extensive expertise.
Eyres commented: “Before we created the LIFE metric, if someone wanted to quantify the impact of a land-use change they’d have to do a very complicated, bespoke analysis requiring a lot of computational power and a lot of expertise." She added: “Now it’s very simple to put a figure on the global change in extinction risk. It makes the information accessible to a huge diversity of people.”
Ball concluded by emphasizing individual choices: if current patterns continue globally without changes in agricultural land use or diets, between 700 and 1,100 vertebrate species may go extinct within this century—a number he believes is an underestimate.