What if...the world turned vegan?

Vanessa Baird dreams on. Or maybe not?

A billboard campaign, created by Californian artist Karen Firito, offered passers-by an arresting set of choices.

They could do their bit to save 1,300 gallons (4,921 litres) of water in drought-blighted California by: not flushing the toilet for six months; or not showering for three months; or not eating just one burger today.

Yes, that’s it. One beef burger!

The online version of the campaign reveals a pound (450 grams) of potatoes uses about 24 gallons (90 litres) of water to produce, bread 193 gallons (730 litres) – and beef a whopping 5,214 (19,737 litres). All animal products rank high – cheese is 896 (3,391 litres).

But suppose we all – and this is very blue skies – the whole world, moved to a plant-based diet? What would happen?

In 2016 Marco Springmann led a team that crunched the figures at the Oxford Martin Programme on the Future of Food, and came up with the startling calculation that if the world suddenly adopted a vegan diet in the year 2050, in that single year greenhouse gas emissions could be reduced by two-thirds.

However, a 2019 correction to research published in Science by Joseph Poore and T Temecek comes up with a lower figure. It indicates that a ‘no animal products scenario’ delivers a 28-per-cent reduction in global greenhouse gas emissions across all sectors of the economy (relative to 2010 emissions). Still significant, but not nearly so dramatic.

Researchers have looked at other global benefits of veganism. A broadly healthier diet could save five million lives a year, a vegetarian diet seven million; but a vegan diet would have the biggest impact, preventing eight million deaths from chronic diseases, says Springmann.

A vegan future would also free up space and resources for growing food. According to research published by The American Journal of Clinical Nutrition a meat-eater’s diet requires 17 times more land, 14 times more water and 10 times more energy than a vegetarian’s. This is mainly because we use a large proportion – 68 per cent – of the world’s agricultural land for growing crops to feed livestock. Harvard Professor of Medicine Walt Willett reckons we could banish most world hunger today with about 40 million tonnes of food – yet 760 million tonnes is fed to farm animals every year.

With world population set to rise from 7.5 billion to 10.5 billion by 2050, pressure on resources would increase. But, as writer and environmentalist Paul Allen points out, there is another, more political issue to be tackled. ‘Right now, we already produce more than 1.5 times the amount of food needed to feed everyone on the planet. It just doesn’t get to everyone in need. In other words, having enough to eat is as much about politics and big business as dietary choices,’ he writes for BBC Good Food.

the shift to plant-based food won’t happen overnight

And there is the fact that the global meat and dairy industries provide work for millions of people, often in poor communities around the world.

And the animals? What would happen to all the animals bred for human consumption? Would cows take over the world? Would they be slaughtered? Or taken into sanctuaries? Would they return to the wild? Some farm breeds, like broiler chickens, would not survive in the wild; others, like sheep or pigs, would do better.

But, in spite of a dramatic growth in veganism – or at least consumption of vegan products – in recent years, the shift to plant-based food won’t happen overnight, enabling farmers to scale down breeding as demand falls.

What happens in populous Asia will have a huge impact. Driven by the need to tackle climate change, rising obesity and diabetes, in 2016 the Chinese government released new guidelines aimed at getting the nation’s 1.3 billion people to reduce their meat consumption by 50 per cent by 2030.

So maybe the idea of a vegan world by 2050 is not quite so (plant-based) pie-in-the-sky, after all…