One of the trickiest issues to factor into dietary health advice is the impact of food on biodiversity. It is hard enough to track where your food has come from. Trying to nail down its effects on biodiversity loss or enhancement is even harder. We can draw broad conclusions but not yet be specific enough.
Over 30 years, methods have been refined to calculate foods’ carbon or water footprints. Some of this work is well summarised by Prof Sarah Bridle, an astrophysicist at Manchester’s famous Jodrell Bank, who turned her attention to the question of which foods have what CO2e impacts, summarises this work clearly. Or think of the vast UNESCO database which Prof Arjen Hoekstra and colleagues built up at the University of Twente in the Netherlands on how much water was used in each of 30,000 or so foods. A cup of coffee has used about 140 litres.
Now come to biodiversity. We have excellent knowledge of which crops are particularly important if we are troubled by the destruction of Amazon rainforest and the Cerrado. Greenpeace could urge burger and meat companies to reject meat reared on Brazilian soy. But if we want to know biodiversity impacts of UK, EU or US food products, we find little but general assessments. Broadly, organic produce fares better because no agrichemicals are used. Farm intensification has lowered biodiversity. But there are no big databases to help consumers decide which meal is more beneficial to biodiversity.
The broad case is made by Prof Tim Benton and colleagues at Chatham House in their sober report on the ongoing biodiversity crisis. Policy-makers cannot continue to duck how important biodiversity is, they argue. They urge the world to reverse rising meat and dairy consumption.
The focus of the huge Dasgupta Review of the Economics of Biodiversity, led by Prof Sir Partha Dasgupta for the UK Government, is different. If your best friends are economists, this one is for you. Only a heavyweight economist such as Dasgupta could produce such an excoriating report. Economists flout biodiversity by denying it even enters into national or commercial accounts, he says. His solution: cost biodiversity and we’ll treasure it.
I loved the critique but am unconvinced that costing is a policy ‘killer argument’. We’ve had estimates of diet’s externalised costs on health for decades, but the avalanche of ultra-processed products and global march of the nutrition transition have rolled on. Reducing biodiversity to cash might convince some FoodCo CEOs, but only if they were forced to do such accounting. It’s law and regulation changes we need, surely.
The good news, however, is that biodiversity creeps up the agenda. How to translate it soon for consumers is my question. What’s a good diet for biodiversity?