By David Suzuki
Our food systems have huge impacts on human and planetary health. Growing, producing, processing, transporting and eating food all contribute significantly to climate-altering emissions — especially in affluent areas where people consume more of everything, particularly meat. Global food systems are also major water users and polluters. And agriculture takes up massive amounts of land and is a major factor in habitat loss and destruction.
A new Oxford University study confirms what vegans have been saying for years: eating an entirely plant-based diet significantly reduces emissions, pollution and land conversion.
The comprehensive study, published in Nature Food, linked “dietary data from a sample of 55,504 vegans, vegetarians, fish-eaters and meat-eaters with food-level data on greenhouse gas emissions, land use, water use, eutrophication risk and potential biodiversity loss from a review of 570 life-cycle assessments covering more than 38,000 farms in 119 countries.”
Researchers found that vegans had one-quarter the dietary impact of high meat-eaters (more than 100 grams a day) for greenhouse gas emissions, land use and eutrophication (an overabundance of nutrients, algae and plants in water systems), and around 34 and 46 per cent for biodiversity loss and water use, respectively.
It’s important because food systems create about one-third of global emissions (including potent methane from livestock farming; methane emissions were 93 per cent lower for vegan diets than high-meat diets!) and are responsible for 70 per cent of freshwater use and 78 per cent of freshwater pollution.
The good news is that, while vegan diets are better all around, reduced-meat diets (less than 50 grams a day) and vegetarian diets are also substantially better for the environment and climate than high-meat diets. The study showed that low-meat diets had half the impact of high-meat diets on emissions, water pollution and land use. In the U.K., that would be equivalent to taking eight million cars off the road. “However, the differences between low-meat, pescetarian and vegetarian diets were relatively small,” the Guardian reported.
A vegan diet is much better for the environment than all of them — half again the emissions impact of a low-meat diet — but cutting back on meat and animal products is a step in the right direction and can make a difference.
Although other ways to reduce food system impacts are needed — such as cutting food waste, increasing sustainable and regenerative agriculture and supporting local food production — a shift in the way people eat and drink, especially in wealthier nations, will have the greatest overall effect.
Reforming agricultural practices to protect soils and their ability to sequester carbon is critical, and here we can learn much from people who have lived in place for millennia and discovered how to feed themselves without depleting the systems that support agriculture, from small- to large-scale.
Some impacts from animal agriculture can be reduced — by adding seaweed to feed for pigs and sheep to reduce methane emissions, for example. But that’s kind of like the oil industry using carbon capture and storage to reduce production emissions; it’s more about finding ways to continue destructive practices than taking the action necessary to curtail them.
Reducing or eliminating meat from your diet is also much healthier — and delicious! A well-balanced vegetarian or vegan diet includes more fruit, vegetables, nuts and legumes, and so is lower in cholesterol and higher in fibre. Studies show plant-based diets reduce the risk of heart disease, diabetes, dementia, high blood pressure, obesity, some cancers and more.
With any diet, it’s crucial that people get the nutrients they need. That means nutritional requirements must often be met in different ways for different people in different places — a vegan diet isn’t practical for everyone, especially people in the North who have relied on and had access to fish and game for millennia.
It also means those who choose a vegan diet must ensure they’re getting a good balance of proteins, minerals and vitamins — especially vitamins B12 and D, iron, zinc and calcium — which can mean using fortified foods and supplements along with bioavailable plant sources.
We wrote recently about the need for privileged people and countries to curtail what many would consider “luxuries” if we’re to get serious about the climate crisis. Excessive meat consumption is one luxury the world can no longer afford.
David Suzuki is a scientist, broadcaster, author and co-founder of the David Suzuki Foundation. Written with David Suzuki Foundation Senior Writer and Editor Ian Hanington.
Learn more at davidsuzuki.org.
Oxford University study:
Taking eight million cars off the road:
Cutting food waste:
Also much healthier:
Vitamin B12 and D, iron, zinc and calcium