Replacing 20% ​​of global beef consumption with microbial protein, such as Quorn, could halve the destruction of the planet’s forests over the next three decades, according to the latest analysis.

The move would also halve emissions from the global food system, by reducing tree felling and methane emissions from livestock. Previous studies have shown that meat substitutes have a smaller environmental footprint, but this latest analysis is the first to assess the impact this could have around the world.

Deforestation also devastates wildlife but is proving very difficult to stop. Experts say the best way is to reduce demand for the products causing the destruction, for example by replacing them with greener alternatives. The microbial protein is brewed in hot bioreactors, like beer, with the sugar-fed microbes. The protein-rich product could taste and feel like meat and be just as nutritious, the researchers said.

Today, 83% of agricultural land is used for livestock and their fodder crops, but the meat and dairy products produced represent only 18% of the calories consumed by humans. Production of meat from ruminants – mainly beef, but also lamb and goat – has more than doubled since 1961, but a series of studies have shown that meat consumption in rich countries must fall drastically to overcoming the climate crisis.

“The food system is responsible for a third of global greenhouse gas emissions, with ruminant meat production being the main source,” said Dr Florian Humpenöder, a researcher at the Potsdam Institute for Climate Impact Research (PIK) in Germany, which led the study. “The good news is that people don’t have to worry about being able to eat only green vegetables in the future. They can continue to eat burgers and such, it’s just that these burger patties will be produced from a different way.

The research focused on microbial meat because it had been produced on an industrial scale for 20 years and was already available, said Dr Isabelle Weindl, also at PIK. “Even taking into account sugar as a raw material, microbial proteins require much less agricultural land than [with] ruminant meat. Previous studies have shown that the protein quality of microbial meat is equivalent to that of beef, but it requires 90% less land and water and produces 80% less greenhouse gas emissions.

The study, which was published in the journal Nature, used computer models that included intermediate projections of socio-economic factors such as rising demand for beef, world population growth, rising income and changes in international trade.

The 56% reduction in deforestation – 78 million hectares (193 million acres) – resulting from replacing one-fifth of beef with microbial protein has occurred in Latin America and sub-Saharan Africa. Significant deforestation still occurred in the modeling due to the production of other foods, such as palm oil and cocoa.

The researchers found that microbial protein substitution largely negated predicted increases in demand for beef, meaning that new grazing areas did not need to be cut into forests. Increasing the proportion of beef replaced to over 20% resulted in lower yields as much of the deforestation had already been avoided, with 50% replacement resulting in an 82% reduction in deforestation by 2050 .

Microbial proteins can be produced from a range of microorganisms, including bacteria, but the main source on the market today is produced from fungi, with the market leader being Quorn. “The best alternative to meat is to eat less,” Humpenöder said. “But [microbial protein products] can help people turn away from meat.

The study did not analyze the effect of plant-based alternatives to meat, but these are also expected to significantly reduce environmental impacts. Meat grown in bioreactors from animal cells is still in an early stage of development and was not included in the study due to a lack of appropriate data.

Dr Tilly Collins of Imperial College London, who was not part of the study team, said: “Although the predictions of these models are highly dependent on our ability to provide such protein substitution, there is no doubt that the effectiveness of biotech alternatives offers enormous future potential for a more sustainable food supply.

“Governments and food producing companies need to coordinate to develop appropriate standards [for microbial protein] and therefore future public confidence. Our nuggets may never be the same again.

The bioreactors used to create microbial proteins require heating, and the use of high-carbon electricity sources would offset some of their benefits, but green electricity is growing rapidly as costs continue to fall.

Humpenöder said: “Microbial protein should not be seen as a magic bullet, but rather as part of a grand transformation of the entire food and agricultural system, combining it with reductions in food waste, incentives to eat healthier and disincentives the sale of products with a strong environmental impact.