Food for thought
Greenhouse gas emissions can be curbed by what’s on your plate. But do diets that support the planet’s health also support yours? As we mark Earth Month, Laura Tilt chews over the science...
THE EXPERT
Laura Tilt is a registered dietitian and health writer
Travelling by train. Buying pre-loved. Switching banks so you’re no longer supporting one that finances fossil fuel projects. All commendable ways of showing up in the fight against climate change. But if you’re in the market for amethod of effecting change you can engage with every day, your diet is agood place to start.
Climate scientists agree, flagging that food systems contribute over a quarter of the world’s planet-heating greenhouse gas emissions, thanks to the changing land use involved in meeting global food demand, as well as the emissions involved in food production. The message is sinking in, with more than 75% of those polled by Ipsos Mori and the Food Standards Agency agreeing that it’s important to buy food with alow environmental impact. But is what’s good for the planet good for your health?
That meat production (especially red meat) is a significant contributor to climate change is unlikely to come as a surprise. It’s the biggest source of methane – a potent greenhouse gas (GHG) emitted via belching cows (charming), along with manure. It drains an eye-watering amount of land and water, too; 1,695 litres of water goes into making the average quarter-pounder, according to the UN Environment Programme.
It means whatever way you cut it, the environmental impact of animal foods is greater than plant-based foods. Arecent Oxford University study comparing the environmental effects of the diets of over 50,000 people showed vegan diets had 30% of the environmental impact of highmeat diets. Even among carnivores, there was a 30% difference between low meat eaters (zero to 50g a day) and high meat eaters (100g or more a day) for most environmental indicators.
And yet, defining what a sustainable diet looks like is messier than a cow-filled field at lunchtime, with factors such as water and land use weighed up against cost, nutrition and accessibility. Determining the impact of dietary changes isn’t straightforward, either. Advice to eat local is misguided, with food miles a small contributor to GHG emissions.
