Veganism used to be about health and animal welfare. But the goal posts of a growing plant-based diet movement have shifted, with people increasingly motivated to ditch meat for the sake of the planet.

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With around 15% of global greenhouse gas emissions caused by livestock farming, according to the Food and Agriculture Organization, a "new" veganism has emerged on the back of the climate crisis.

In the UK alone, supermarket sales of plant-based substitutes for animal products — many of which claim to be low carbon — have grown 31% in the past two years. 

Faux animal products boomed in 2019. California-based Beyond Meat had the biggest public share offering of the year in May, as its value rose nearly 500% (quarterly sales reported this week also tripled year-on-year).

Impossible Foods founder Pat Brown, who is also a biochemistry professor at Stanford University, wants his plant-based substitutes to drive all livestock farming out of business by 2035. He told the New Yorker last month that "we see our mission as the last chance to save the planet from environmental catastrophe."

But are these highly processed, plant-based vegan meat brands the best way to reduce livestock emissions and combat land degradation?

Climate savior?

A spate of reports, including by the IPCC  and John Hopkins Center for a Livable Future, has stressed the planetary benefits of cutting animal products from our diets.

A Beyond Meat-commissioned life-cycle assessment by the University of Michigan, meanwhile, claims the company's faux burgers, sausages and minces created from pea or mung bean isolate, coconut oil and beetroot juice extract — among numerous additives — require 90% less carbon gas emissions, 99% less water, 93% less land and 46% less energy than equivalent animal-based products.   

Yet such meat alternatives emit around five times more greenhouse gases than unprocessed sources of plant protein according to Marco Springmann, a senior environmental researcher at Oxford University. "They're somewhere between unprocessed legumes, and chicken," he says of the climate impact of highly engineered, meaty vegan products. 

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"If you look at it purely from an environmental perspective, they would still make a big contribution to mitigating climate change," Springmann told DW, "just not as big a contribution as moving to an arguably more healthy diet that includes plenty of fruit and vegetables, some nuts and seeds, whole grains, minimally processed beans and lentils."

Legumes like beans and lentils are the ultimate climate-friendly source of minerals and proteins. They require no greenhouse-gas-emitting fertilizers because they fix nitrogen from the atmosphere. The best thing for the planet would be to eat beans and lentils as they are, or, if you want something in a burger form, to simply crush them at home and make your own veggie burger, said Springmann.

Still, Caterina Brandmayr, senior policy analyst at UK-based Green Alliance that has written a report calling on government to fund low-carbon food innovations such as plant-based meat and even lab-grown meat, says if meat lovers were willing to switch at least part of the time, it would go some way to helping climate mitigation.

The key here is satisfying a broad range of eating patterns and demands for taste. "We need to respond to a wide spectrum of preferences, to enable, as much as possible, a wider range of people to benefit from the health and lower environmental impact that plant-based eating can provide," Brandmayr told DW.

Vegan junk food?

Springmann is the co-author of a report on the climate and health "co-benefits" of dietary change which argues that transitioning toward plant-based diets could limit food-related greenhouse gas emissions by up to 70% by 2050, and reduce global mortality by up to 10%. 

This latter metric points to another problem with meat substitutes, which Springmann equates to "still pretty much junk food." Nutrients are lost through processing of the base pea isolate and many of these products have high sodium levels — the Impossible Burger sold at Burger King packs more salt that the real meat Whopper Burger.

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Brandmayr is confident faux burgers can improve their health credentials as recipes evolve. "It is still something to be welcomed," she said, suggesting such products could help confirmed carnivores transition to plant-based diets.

But the mania for creating that authentic meat taste means potentially unhealthy and unsustainable ingredients are added.

Springmann points to the heme iron molecule — used to create the meaty taste in the Impossible Burger — which is derived from plant sources using GMO. Heme iron, normally only present in meat, has been implicated as being part of the reason why red meat intake increases the risk for colon and rectal cancers, Springmann says.

New vegan future

San Francisco-based brand Just has been offering plant-based alternatives to meat and other animal products for over five years. Its liquid egg, used for everything from scrambles to French toast, is made primarily from high-protein, non-GMO mung bean protein isolate.

Just Egg claims to use 98% less water, 86% less land, and to have a 93% smaller carbon footprint than conventional animal sources. But while the premium-priced product appeals to new vegans, the energy required to process such legumes into an isolate might seem questionable when you consider that they also lose fiber and nutrients along the way

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Faux meat is a favorite of "flexitarians," who salve their conscience by choosing the occasional fake meat Impossible Burger at Burger King — or the Beyond Meat version now being trialled at McDonalds. That might be the first step to full veganism, but with no sign of these fast food chains taking the real thing off their menus, for now it looks like little more than a complement to mass meat consumption.

The recent adoption of vegan meat options at these global chains seems to be partly a response to a demand by global investors in January that the fast food giants significantly reduce the emissions and water usage of their meat and dairy suppliers.

It's something. But if new vegans really want to fight the climate crisis, maybe they should go old school and return to ancient tofu and tempeh-based meat substitutes — created of course from non-GMO sources.