At some point this century, our food production system will collapse. Currently, its most critical link is meat, particularly beef, whose production, according to data from the FAO, has doubled in the last sixty years. 80% of agricultural land is used for cows, pigs or chickens, either in the form of pasture or to grow the grain to feed them. Agriculture is responsible for a third of all emissions, with cattle as the primary culprit. As the world population grows, humans will be faced with a dilemma: either we stop consuming so much meat, or we look for other sources of animal protein. Science is already pointing to several alternatives: insects, laboratory meat and nutrients of microbial origin. Different models indicate that they are as at least as friendly to the planet as vegetarian diets, if not more.
Scientists from the Potsdam Institute for Climate Impact Assessment and the World Center for Plants in Taiwan have modeled what would happen if a percentage of the meat consumed were changed to meat alternatives. The study, published a few days ago in Nature, focuses on proteins from fungi. Isabelle Weindl, PIK researcher and co-author of the study, explains the choice: “There are plant-based alternatives, such as soy burgers, and animal cells grown in a petri dish, also known as cultured meat. But there are also microbial proteins derived from fermentation.” For her, those are the most promising. With a high protein content, their texture is reminiscent of steak, thanks to the stringy structure of fungi such as Fusarium venenatum. In addition, unlike vegetable alternatives such as tofu or seitan, among its components is a series of essential amino acids. Sausages and hamburgers have already been formulated with these mushroom mycoproteins.
Most importantly, its production can be largely decoupled from agricultural production. It does not require the deforestation of new surfaces and would free up millions of hectares. “Our results show that even taking into account sugar as a raw material, microbial protein requires much less agricultural land than ruminant meat to offer the same amount of protein,” says the German scientist.
The researchers envision that a certain percentage of meat in the diet will be replaced by these microbial proteins by 2050. If, within 30 years, it were possible to replace 80% of animal proteins with fungal ones, the problem of global deforestation could almost disappear, especially in the Amazon and Congo basins, which are currently the most affected regions. Greenhouse gas emissions would be 87% lower than they would be if the current system remained. Although new land would have to be dedicated to growing sugar cane or sugar beets, as sugars are essential for fermentation, that land could come from reclaimed pasture and fodder crop land. In addition, fewer cows ruminating would decrease emissions of methane, a gas with a warming potential 23 times higher than that of CO₂.
A less ambitious scenario, with only a 20% substitution, would still bring significant improvement. Says Florian Humpenöder, also from PIK and the study’s lead author, “We see that if we replace 20% of ruminant meat per capita by 2050, annual deforestation and CO₂ emissions from land use change would be reduced by half compared to a conventional scenario.” Reducing livestock numbers not only reduces pressure on the land, explains Humpenöder, but also decreases methane emissions from livestock and nitrous oxide emissions from fertilizer and manure management.
Rachel Mazac, a researcher at the Institute of Sciences for Sustainability at the University of Helsinki, published a paper at the end of April on the incorporation of so-called new foods into the European diet and how they would help reduce the environmental impact of food production. She summarizes the results of this work in an email: “The foods with the greatest potential turn out to be insect meal and cultured milk.” But she also highlights microbial proteins, selected for “their lower impact and a nutritional profile that meets our dietary requirements.”
Her study, published in Nature Food, concludes that replacing proteins of animal origin with those offered by these new foods could reduce the impact of protein cultivation on climate change by over 80%. When comparing a vegetarian diet and one that includes insects, fermented dairy and mycoproteins, the study finds a slight advantage for the former over the latter, but, as Mazac says, with a vegan diet people “will also be able to stay healthy, feel good and have less environmental impact.”
From a nutritional point of view, it would be healthy to significantly reduce the consumption of animal products in current European diets. Both Mazac and Humpenöder now show that these alternatives to animal proteins are also good for the planet. A well-known supermarket chain has been selling insects for five years. Many grocery stores have long had a variety of plant-based meats, and in February the European Union authorized the marketing and sale of acheta domesticus, crickets, as food. But they have yet to play a role in most people’s diet.
For Ascensión Marcos, research professor at the Institute of Food Science and Technology and Nutrition at the CSIC (ICTAN), much more research is still needed for these models to have a real application. “Many unknowns remain to be resolved,” she says, including the palatability of these new foods. “If they don’t like it, they don’t like it,” she argues. Acknowledging that it is a cultural issue, she says that “it is one thing to give insects to an animal, and you eat the animal, and another to be the one who eats the insect.” There are historical examples of cultural changes that have lowered or eliminated the aversion to certain foods, though. She mentions the case of ham in East Asia or “seafood, which for the Japanese was like eating insects.”
Marcos also raises an objection that goes beyond science. “Whether we like it or not, we are omnivores and we have to eat everything.” The real problem, she concludes, “is that we have a very poor diet, we eat an excessive amount of protein, few carbohydrates and a lot of fat. This has its impact on us and on the environment, and the food industry does not help.”