Untangling the worst impacts of livestock on our planet won’t require us to completely reject meat and dairy: in fact, replacing 50% of these products with novel plant-based substitutes in our global diet would chop agricultural and land-use emissions by 31% in just 30 years. More intriguingly, that figure could be doubled if the land released by livestock was devoted to reforestation.
There’s lots of talk about how transitioning to novel plant based foods like meatless burgers and soy sausages can revolutionize our food system. But until this study there hasn’t been a global analysis that looked at what these direct substitutes would actually accomplish in terms of emissions and land use.
Writing in Nature Communications, the study authors explain that they wanted to close this gap, by looking at the possible meat protein substitutes that could be made from isolates of soy, rapeseed, potato, wheat—all of which are already used to make replacement foods for chicken, pork, beef, and milk. Crucially, they made sure these substitutes would be nutritionally equivalent to their animal counterparts.
Then they modeled a set of dietary changes up to 2050 that would introduce these substitutes into the global diet at a gradually increasing rate, up to 50%. Using the Global Biosphere Management Model, they explored the impact of these changing and increasingly ambitious diets on land-use, greenhouse gas emissions, food security and biodiversity, assuming the climate stays the same.
Alongside a one-third decline in agricultural emissions, the most significant benefit of replacing half the meat and milk in our diets is that there would be a net reduction in the loss of wild land, including forests, as livestock farms shrink.
“The impacts are wide—from reduction of agricultural input use, such as water and nitrogen fertilization, through reducing GHG emissions, to saving forests and natural ecosystems—and by that reducing biodiversity loss,” says Marta Kozicka, a researcher at Austria’s International Institute for Applied Systems Analysis, and lead author on the new research. “And this is while maintaining the same level of consumption of calories, proteins and amino acids.”
The greenhouse gas reductions were in line with what other studies had shown, Kozicka says. But “the really interesting part was to see the potential climate and biodiversity impacts of additional measures taken to restore the agricultural land.”
Overall, 653 million hectares of land would be spared through the 50% substitution of dairy and meat, the authors calculated. If the spared land that overlaps with forest ecosystems was restored to lush, carbon-trapping habitat again, this would double the sector’s emissions savings. In turn that would achieve 92% of the previously estimated global land sector mitigation potential for climate change.
More specifically, for biodiversity, the newly-reforested land could achieve up to 25% of the restoration that the Kunming Montreal Global Biodiversity Framework estimates we need to support wildlife, and reach our global biodiversity targets by 2030.
On top of these striking findings, the researchers note that livestock declines in China would produce the greatest land sparing potential, freeing up a quarter of the total land area calculated in the study, and accounting for 22% of the associated emissions reduction. Sub-Saharan Africa meanwhile, is where the potential is highest to reduce forest and natural habitat loss when we shift some of the nutritional burden from livestock to plant-based substitutes.
And if a globally-reformed diet sounds ambitious, it probably is: diets can be notoriously difficult to shift, research shows. But, the authors on this study say they are optimistic that it can be achieved. They also note that even half the projected change—a 25% replacement of meat and meat milk—would yield large planetary benefits by sparing 250 million hectares of land.
“The 50% substitution scenario is a realistic one, especially if the novel plant-based alternatives may be combined with traditional plant-based products and other novel meat substitutes,” they researchers argue in their study. “A major factor that will determine how these markets evolve is the price of the products.”
Kozicka et. al. “Feeding climate and biodiversity goals with novel plant-based meat and milk alternatives.” Nature Communications. 2023.
Image: @Anthropocene Magazine