By assessing the productivity of land, the team calculated the annual per-kilogram biodiversity effect of dozens of food commodities. Popular foods grown in tropical regions such as coffee, cocoa, tea and bananas have a much greater impact on species extinctions than those from temperate areas, due to the rich biodiversity present in the tropics.
The study identified beef and lamb as having the greatest impact on species extinction, though the risk varies substantially depending on where meat is produced. The UK's extinction footprint from food is almost entirely driven by imports. Beef from Australia and New Zealand, which Britain now imports in larger quantities since Brexit, is thirty to forty times more likely to contribute to species extinctions compared to beef produced in the UK and Ireland.
Land-use changes and habitat destruction for farming are described as the most damaging ways our dietary choices affect biodiversity. Dr Thomas Ball, postdoctoral researcher at Cambridge's Department of Zoology and lead author of the report, stated, "Every time anyone eats anything, it has an impact on the other species we share the planet with." Ball explained, "Rearing the cattle for one kilo of beef needs a huge amount of land, which displaces a lot of natural habitat. On average, that has a much bigger impact on species' survival than growing one kilo of vegetable protein like beans or lentils." He added, "Our study shows that eating beans and lentils is 150 times better for biodiversity than eating ruminant meat. If everyone in the UK switched to a vegetarian diet overnight, we could halve our biodiversity impact."
The research uses the LIFE metric (Land-cover change Impacts on Future Extinctions) developed by Cambridge, which quantifies how shifts in land use - including deforestation and habitat restoration - affect the extinction risk for over 30,000 terrestrial vertebrate species.
Guiding policy decisions is a core aim for the researchers, who note that almost one third of the global land surface has been repurposed for agriculture in the last sixty years, making species conservation a crucial issue. Ball and colleagues, working with Dr Jonathan Green at the Stockholm Environment Institute and the Joint Nature Conservation Committee, incorporated the LIFE metric into the UK's government toolkit for assessing the environmental impacts of food consumption. They compiled data on consumption and provenance for 140 food types and assessed how agricultural and trade policies affect global species extinction risks.
Ball concluded, "When it comes to decisions about producing food it's not enough to focus on one country in isolation. 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."
Research Report:Food impacts on species extinction risks can vary by three orders of magnitude
Related Links
University of Cambridge
Farming Today - Suppliers and Technology
| Subscribe Free To Our Daily Newsletters |
| Subscribe Free To Our Daily Newsletters |
