Is a vegan diet better for the environment?

Why are more of us than ever cutting out meat, fish, dairy and eggs? For many, the environment is a big factor. This year, after a record number of people signed up for Veganuary, James Poole, a researcher at the University of Oxford, estimated the environmental impact of the month-long charity campaign, 'for the 350,000 people expected to take part in 2020,' he said, 'this would save as much greenhouse gas emissions as moving 160,000 cars from the road, or about 400,000 to 500,000 single flights from London to Berlin.'

Why is a vegan diet better for the planet?

One answer is the huge environmental cost of industrialised animal farming.

Today, the UN says meat and dairy (farmed livestock) accounts for 14.5% of all manmade greenhouse gas emissions. That’s roughly equivalent to the exhaust emissions of every car, train, ship and aircraft on the planet!

If we all went vegan, the world’s food-related emissions would drop 70% by 2050, according to a 2016 report on food and climate in the academic journal, Proceedings of National Academy of Sciences (PNAS).

Sound good? Well, it is. But, as always, the devil’s in the detail.

Just as it’s possible to be vegan and still eat unhealthily – without the right food balance, vegans can miss out on important vitamins, proteins and fatty acids, and eat too many saturated fats – there are some vegan foods which aren’t great for the planet.

If you’re vegan (or thinking about going vegan), and want to keep your environmental footprint as light as possible, here are some things to consider:

Alternative milks

Did you know that it takes 74 litres of water to make a single glass of almond milk? That’s more than a typical shower. Rice milk is also quite ‘thirsty’, needing 54 litres of water per glass. These numbers are still low compared to dairy milk, but they’re far higher than soya or oat milk.

The following table shows how alternative milks compare when it comes to carbon emissions, land use and water use:

Avocados

Smashed on toast or snapped on Instagram, this Millennials’ favourite is another water-hungry crop. According to the Water Footprint Network, 2,000 litres of water are needed to produce just one kilo of avocados. That’s four times the amount needed for the same volume of oranges, and 10 times more than for tomatoes.

What’s more, their rise in popularity has created some unexpected environmental consequences. In Mexico, for instance, demand for avocados has led to forests being illegally destroyed by farmers keen to profit from these increasingly valuable crops.

If you want to buy avocados sustainably, one option is to choose those certified by a scheme like Fairtrade or Equal Exchange. And if you want to get the avocado’s amazing nutritional benefits from other foods, there are lots of alternatives.

As journalist Joanna Blythman explains, 'if you’re looking for vitamin K, broccoli or cabbages have it. If it’s vitamin E you’re seeking, there’s plenty in wheat germ oil, sunflower seeds or almonds. Folate/vitamin B9 is in kidney beans, lentils or cauliflower. If it’s about monounsaturated oils, extra virgin olive oil and sesame or peanut oil are great alternatives.'

Soya

Packed with vitamins, soya beans are also incredibly versatile. You’ll find them in tofu, flour, meat-free burgers, veggie sausages and much more.

So far, so great for vegans. But according to the WWF, soy is the second largest agricultural driver of deforestation worldwide after beef, 'from the US to the Amazon, forests, grasslands, and wetlands are being plowed up to make room for more soy production.'

The good news is that there has been a ‘soy moratorium’ in place in Brazil since 2006. This is an agreement between major soya companies not to buy any of the beans grown on recently deforested land.

It’s also important to remember that the vast majority of soya is grown for the meat and dairy industry. The WWF says only 6% of the world’s soya is eaten directly by humans.

Palm oil

From soap to sweets, margarine to make-up, palm oil is in around half of all supermarket products – and it’s a common ingredient in vegan alternatives, such as non-dairy ice creams and cheeses.

In theory, there’s no problem with cultivating palm oil. The problem is that it’s often grown irresponsibly – and the rapid rise in palm oil production, in Southeast Asia in particular, has caused huge deforestation and pushed the orangutan towards extinction. Environmental campaign group Greenpeace claims an area of forest the size of a football pitch is being lost in Indonedia every 25 seconds to palm oil farmers.

Though some critics aren’t convinced about its environmental credentials, there is a sustainable palm oil scheme, and a growing number of brands have now pledged to produce more sustainable palm oil, including L'Oreal.

Imported fruit

Studies show that vegan diets tend to have far lower carbon, water and ecological footprints than those of meat- or fish-eaters. But in one 2017 Italian study, two vegan participants had extremely high eco-impacts – this turned out to be because they only ate fruit!

As Helen Breewood, research assistant at the Food Climate Research Network (FCRN) explains, fruit that’s been air-freighted into the UK has a very big carbon footprint. (It’s important to remember, though, that ‘food miles’ alone aren’t always the best measure of sustainability – and that some intensively grown local produce can have a bigger footprint than imported food.)

She adds that there are still a lot of knowledge gaps. For example, there is currently little research into fashionable ‘new’ vegan foods – such as jackfruit, often used to create vegan ‘pulled pork’ – so it’s hard to judge their environmental credentials.

Future trends

What does all this mean for our future eating habits? And what will tomorrow’s sustainable diet look like?

Some experts point to technology and the rise of lab-grown, plant-based ‘alternative meats’, such as the ‘bleeding’ vegan burger which arrived in UK supermarkets in late 2018. These have the potential to dramatically slash the environmental footprint of food.

Bill Gates calls them the food of the future. Bruce Friedrich of the Good Food Institute goes further – predicting that, by 2050, almost all meat will be plant-based, or cultivated.

Environmental writer George Monbiot agrees. 'We are on the cusp of the biggest [food] transformation, of any kind, for 200 years', he wrote in the Guardian earlier this year. 'While arguments rage about plant- versus meat-based diets, new technologies will soon make them irrelevant.'

Before long, he says, most of our food will come from the lab, 'after 12,000 years of feeding humankind, all farming except fruit and veg production is likely to be replaced by ‘ferming’: brewing microbes through precision fermentation'.

Other experts believe that living creatures will continue to feature in our future diet – but they won’t be farm animals. Though not vegan, of course, insects are often rich in vitamins like iron and zinc, as well as essential fatty acids like omega-3. They're also low in fat and a good source of protein.

'Insects are nutritionally comparable to meat,' says Dr Duncan Sivell, a scientist at the Natural History Museum. Whether we’re eating insects or using them as animal feed, he says that cultivating insects requires 'less space, less feed, and generates less greenhouse gas'.

Bleeding microbe burgers or pan-fried crickets not your thing? Don’t worry.

'Lab-grown meats are a red herring,' argues Professor Pete Smith of the University of Aberdeen. 'We don’t need them. We can get most of the protein we need from plant-based foods.'

He also questions the rise of new protein sources such as insects – at least in the West. 'Wealthy countries are already massively over-consuming protein...we don’t need alternate protein sources – if we cut in half the amount of protein we are already eating, we would be at healthier levels.'

For our prosperity and the planet, this paints a clear picture. In short, tomorrow’s ideal diet could look pretty similar to today’s – at least in the near future. It means choosing more fruit and vegetables and wholegrains, eating less junk food, meat and dairy.

All of which sounds, well, rather like a vegan diet.

Paul Allen is a former BBC environmental editor and a director at Lark. Find him on Twitter @larkingly

For more on vegan diets, we've collaborated with BBC Future – read more below:

The health benefits of going vegan – BBC Future
Why vegan junk food might be even worse for your health – BBC Future
How a vegan diet could affect your intelligence – BBC Future
The hidden biases that drive anti-vegan hatred – BBC Future
The mystery of why there are more women vegans – BBC Future
Why the vegan diet is not always green – BBC Future
Which milk alternative should we be drinking? – BBC Future