If you’re an environmentally conscious meat eater, you probably feel a little guilty sitting at the dinner table. The meat on our plates has significant environmental costs due to the deforestation, greenhouse gas emissions, and air and water pollution caused by its production. Given the urgent need to combat climate change, this is an uncomfortable reality.
That’s one reason why there’s so much excitement these days about a product that’s only just arrived on supermarket shelves and hamburger restaurant menus: products that look like real meat, but are made without ingredients of animal origin. Unlike the vegetarian, bean- or grain-based burgers of decades past, these plant-based meats (the most popular of which are Impossible Burger and Beyond Meat) are marketed primarily to traditional meat eaters. They claim to replicate the taste and texture of real ground meat, but at a fraction of the environmental cost.
If these novel meat alternatives can meet much of our meat needs—and if they are as environmentally friendly as they suggest, which is not easy to verify independently—they could offer carnivores a way to reduce the environmental impact of their dining choices without giving up one of yours Favorite dishes.
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Some believe this could be game-changing. “People have long been educated about the harms of animal agriculture, but the proportion of vegans and vegetarians remains low,” says Elliot Swartz, a scientist at the Good Food Institute, an international nonprofit that supports the development of alternatives to meat. “Rather than forcing people to change their behavior, we believe it will be more effective to replace products in their diet without requiring them to change their habits.”
There is no doubt that the current meat industry is harmful to the planet. Livestock farming is responsible for about 15% of global greenhouse gas emissions, both directly (from the methane emitted by cattle and other grazing animals and from manure from feedlots, pig farms and chicken houses) and indirectly (mainly due to the fossil fuels previously used fuels). grow fodder). If our planet’s livestock were a country, their greenhouse gas emissions alone would be second in the world, behind only China.
Worse still, the United Nations predicts that global demand for meat will rise 15% by 2031 as the world’s increasingly larger and wealthier population wants more meat on their plates. This means more methane emissions and the expansion of pasture and cropland in formerly forested areas such as the Amazon. Such deforestation threatens biodiversity and further contributes to emissions.
However, not all types of meat contribute equally to the problem. Grazing animals such as cows, sheep and goats have a much larger greenhouse gas footprint than non-grazing animals such as pigs and chickens. This is in large part because only the former burp produces methane, which is produced when gut microbes digest the cellulose in grass and other forages.
The global demand for meat is increasing. Especially in middle-income countries: their increasing wealth leads to them eating more meat.
Pigs and chickens are also much more efficient at converting feed into edible meat: chickens need less than two kilograms of feed to gain weight, pigs achieve this with three to five kilograms of feed. The rest comes from the energy costs of daily life: circulating blood, moving around, keeping warm, fighting germs, and so on. Compare that to the six and ten kilos of feed a cow needs to gain one kilo.
As a result, greenhouse gas emissions from cattle per kilo of meat are more than six times higher than those from pork and almost nine times higher than those from chickens. Paradoxically, grass-fed cattle (often viewed as a more environmentally friendly alternative to beef cattle) are actually a bigger climate polluter because grass-fed animals mature more slowly and therefore spend more months emitting methane.
Build up fake meat
Plant-based meat aims to improve these dire environmental impacts. For example, Pat Brown, a biochemist at Stanford University, founded Impossible Foods after wondering what actions he could take to make the biggest environmental difference. His answer: substitute meat.
To achieve this, Impossible and its competitors essentially break down meat into its basic components and then create an equivalent product from plant-based ingredients. Manufacturers start with plant-based proteins (mainly soy in the case of Impossible, peas in Beyond, and potatoes, oats or equivalent proteins in others) and add carefully selected ingredients to simulate the quality of meat. Most contain coconut oil because it resembles the mouthfeel of animal fats, and yeast extract or other flavorings to add meaty flavors. Impossible even adds a plant-based version of hemoprotein from animal blood for an even more meat-like look and taste.
All of this requires some processing, notes William Aimutis, a food protein chemist at North Carolina State University who wrote about plant proteins in the 2022 Annual Review of Food Science and Technology. Soybeans, for example, are usually ground first, it is made into flour and then the oil is extracted. The proteins are isolated and concentrated, then pasteurized and dried (spray) to obtain relatively pure protein for the final formulation. Each step uses energy, which begs the question: With all this processing, are these meat alternatives really more environmentally friendly than what they are intended to replace?
To answer this question, environmental scientists conduct what is known as a life cycle analysis. Each ingredient in the final product (soy protein, coconut oil, heme, etc.) is traced back to its origin and all associated environmental costs are recorded. For example, in the case of soy protein, the life cycle analysis would include the fossil fuels, water, and land required to grow the soybeans, including fossil fuel emissions from fertilizers, pesticides, and transportation to the processing plant. Added to this is the energy and water used in grinding, degreasing, protein extraction and drying.
Similar calculations would apply to all other ingredients as well as the final assembly and packaging process. Add it all up and you get an estimate of the product’s total environmental footprint.
Supermarkets and restaurant menus already feature a wide selection of hamburgers made without ingredients of animal origin.MTStock Studio (Getty Images)
Unfortunately, not all of these numbers are available. For many products, especially the new generation of plant-based meats, the product details are closely guarded secrets by the companies involved. “They will know how much energy they use and where they get the fat and protein from, but they will not reveal it to the general public,” explains Ricardo San Martín, a chemical engineer who directs the Alternative Meats Laboratory at the University of California in Berkeley. As a result, most life cycle analyzes of plant-based meat products have been commissioned by the companies themselves, including Beyond and Impossible. Researchers outside these companies have little chance of independently verifying them.
Still, these analyzes suggest that plant-based meat offers clear environmental benefits over its animal counterparts. The Impossible Burger, for example, produces only 11% of the greenhouse gas emissions that an equivalent amount of beef burger would cause, according to a study commissioned by the company from sustainability consultancy Quantis. Beyond’s life cycle analysis, conducted by researchers at the University of Michigan, concluded that the greenhouse gas emissions of its burgers were 10% of the greenhouse gas emissions of real beef.
In fact, when independent researchers at Johns Hopkins University decided to get the best estimates possible by reviewing the published literature, they found that in the 11 life cycle analyzes they found, the average greenhouse gas footprint of plant-based meat was just 7% of beef content for the same amount of protein. Plant-based products were also more climate-friendly than pork or chicken, although less noticeable: the greenhouse gas emissions for the types of meat mentioned were only 57% and 37%, respectively.
Similarly, the Johns Hopkins team found that plant-based meat production used less water: 23% than beef, 11% than pork, and 24% than chicken for the same amount of protein. It also saved a lot of land, as plant-based products consumed 2% of beef, 18% of pork, and 23% of chicken for the same amount of protein. Saving land is important because if plant-based meat captures a significant market share, the excess land could be converted into forests or other natural vegetation that sequester CO₂ from the atmosphere and help protect biodiversity. Other studies show that plant-based milk offers similar environmental benefits to cow’s milk.
Be careful with cultivation methods
Of course, how environmentally friendly plant-based meat is depends on the agricultural practices on which it is based. The same goes for meat itself: the greenhouse gas emissions produced by a kilo of beef can vary by more than tenfold between the most efficient and the most efficient producers. Plant ingredients like palm oil grown on plantations that were once rainforests or intensively irrigated crops in drylands cause much more damage than more sustainable crops. And the cultivation of soybeans, a key ingredient in some plant-based meats, contributes significantly to deforestation in the Amazon.
All of this requires a lot of processing and energy. Are these meat alternatives really more environmentally friendly? coldsnowstorm (Getty Images)
However, for most ingredients, it seems likely that even poorly produced plant-based meat is more environmentally friendly than meat from well-raised cattle. According to Matin Qaim, an agricultural economist at the University of Bonn in Germany, who wrote about meat and sustainability in the 2022 Annual Review of Resource Economics, plant-based meat requires much less soy than feeding livestock. “The deforestation of the Amazon is due to increasing demand for food and feed. “If we move away from meat and towards a plant-based diet, we will need less acreage overall and soy doesn’t necessarily have to grow in the Amazon.”
No matter how organic it is, plant-based meat has to overcome some hurdles before it can replace meat. First, according to the Good Food Institute, plant-based meat currently costs 43% more than the products it is intended to replace. This explains why plant-based meat accounts for less than 1% of meat sales in the United States. Its proponents are optimistic and believe that the price will fall as the market develops, but that has not happened yet. And achieving those economies of scale will take a lot of work: Swartz says even achieving a 6% market share will require a $27 billion investment in new facilities.
The steak is not yet cooked through
In addition, all current plant-based meats are intended to replace ground meat products such as hamburgers and chicken nuggets. Whole muscle meat like steak or chicken breast has a more complex fiber structure that alternative meat companies have yet to reproduce outside of the lab.
Part of the problem is that most plant proteins are spherical in shape, while true muscle proteins tend to form long fibers. To get a product with a meat-like texture, scientists need to turn golf balls into rope, says David Julian McClements, a food scientist at the University of Massachusetts, Amherst and editor of the Annual Review of Food Science and Technology. There are ways to achieve this, often using high-pressure extrusion or other complex technologies, but so far no one has a market-ready whole-muscle product (a mushroom-based product that has been sold in some countries for decades). The Quorn name is inherently fibrous, but its sales never took off in the United States. Other companies are also working on meat substitute products based on mushroom proteins.
The environmental impact of the two leading plant-based burgers is significantly lower than that of a comparable beef burger, according to detailed studies commissioned by the two companies.
McClements is experimenting with a different method of making plant-based bacon: He creates plant-based analogues that are separated from muscle and fat, then 3D prints the bacon’s distinctive marbling. “I think we have everything we need to achieve that,” he says.
Some critics also point out that a shift toward plant-based meat could undesirably increase the industrialization of global food systems. Most alternative meat products are manufactured in factories, and their demand for plant-based proteins and other ingredients favors big agriculture, with its well-documented problems such as monoculture, pesticide use, soil erosion, and water pollution from fertilizer runoff. Plant-based meat will reduce the impact of these unsustainable agricultural practices, but will not eliminate them unless current agricultural practices fundamentally change.
Of course, all the fuss about alternative meats ignores another dietary option that has the lowest environmental footprint of all: eating less meat and more legumes, grains and vegetables. According to Johns Hopkins researchers, additional processing of plant-based meat produces 4.6 times more greenhouse gases per unit of protein than beans and seven times more than peas. Even minimally processed traditional plant proteins like tofu outperform plant-based meats in terms of greenhouse gas emissions. Additionally, most people in rich countries consume much more protein than they need, so they can reduce their consumption without having to find a substitute.
But this option may not be attractive to today’s carnivorous majority, so alternative meats provide a useful solution. “Would you rather have people eat beans, cereal, tofu, and lots of fruits and vegetables?” Yes,” says Bonnie Liebman, nutrition director at the Center for Science in the Public Interest. The expert from the organization Healthy Eating Defense clarifies: “But there are many people who like the taste of meat and are probably not convinced by tofu.” If they can be convinced by Beyond Meat and that helps curb climate change, I am totally for it.”
Plant milk
Meat is not the only animal protein source with a high environmental cost. Dairy products also cause large greenhouse gas emissions through the rumination of cows and sheep and through the cultivation of feed. Here, too, plant-based alternatives, many of which are already available in supermarkets, can be more environmentally friendly, at least in some ways.
However, the level of respect depends on how your footprint is measured. One way is to express the environmental cost per liter of milk. All plant-based milks are characterized by this measure. Soy milk, for example, requires only 7% land and 4% water and emits only 31% greenhouse gases. Oat milk requires 8% land and 8% water and emits only 29% greenhouse gases. Even almond milk – often considered a poor choice because almond orchards use a lot of fresh water – uses only 59% as much water as real milk.
However, not all plant milks provide the same nutrients. While soy milk provides almost the same amount of protein as cow’s milk, almond milk only provides 20% – an important point for some. Therefore, per unit of protein, almond milk produces more greenhouse gases and uses more water than cow’s milk.
Article translated by Debbie Ponchner.
This article originally appeared on Knowable en español, a nonprofit publication dedicated to making scientific knowledge accessible to everyone.
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