Biodiversity-conscious eaters could consider substituting potatoes for rice, cutting down on beef and lamb and asking where their beans, lentils and chickpeas are grown to reduce their impact on nature, a new study has found.
Scientists analysed 151 popular recipes around the world for their biodiversity impact. They found meat dishes were the worst offenders: recipes including chilli con carne, salsa verde pork and a Spanish lamb dish called lechazo, all had high biodiversity damage scores compared with vegan and vegetarian ones.
The massive environmental impact of eating meat has been well established, and the study reinforced this, with meat dishes scoring more than vegetarian or vegan dishes across almost all locally and globally produced scenarios. Brazilian-raised beef topped the charts. But the study, published on Wednesday in Plos One journal, also had surprising findings about the biodiversity footprint of some grains and legumes.
Recipes that use rice and legumes – like the chickpea-based dish chana masala and the kidney bean rajma curry – can cause problems too, depending on where ingredients are grown. “The origin of the beans or lentils you are using matters quite a bit,” said Roman Carrasco, one of the paper’s authors and an associate professor of biological sciences at the National University of Singapore (NUS).
The study’s lead author, Elissa Cheng, a life science graduate at the NUS department of biological sciences, said: “The study highlights particular problems for dishes using ingredients from tropical areas rich in biodiversity, including Brazil and Mexico.”
India “presents a perfect storm”, Carrasco said, because it has high levels of biodiversity, including many endemic species that can only live in very specific areas, combined with “high levels of those critical areas being heavily encroached by crops like rice, chickpeas, beans and lentils”.
Carrasco said examples of Indian species particularly at risk from industrial legume production include “the pygmy hog – the smallest and rarest species of pig – the Elvira rat [and] the Kondana soft-furred rat”.
The study found dishes doing the least harm to biodiversity were those with starchy ingredients such as potato and wheat, including Polish pyzy potato dumplings and Chinese mantou, a steamed wheat bun.
The United Nations Environment Programme describes global food production, particularly animal agriculture, as the primary driver of biodiversity loss, and a key part of the problem is the land area required for livestock and their feed.
“Brazilian cattle, for example, need a lot of space. So do Spanish lambs,” Carrasco said. And while legumes are “an excellent crop” in terms of efficient land use and high nutritional value, they could be better grown in less biodiverse areas.
Cheng said: “The findings suggest we might need mechanisms to compensate countries to preserve their biodiversity [instead of using the land for agriculture] while we grow more things in countries that have already cleared most of their natural habitat for agriculture, like parts of Europe and North America.”
To calculate the biodiversity footprint of each dish the scientists used crop and pasture area data, as well as data from the International Union for the Conservation of Nature red list of threatened species and BirdLife International, to calculate the agricultural footprint of each ingredient, the number of threatened species and the “range rarity” affected by converting natural habitats to crop or pastureland. High range rarities mean a species has a very small remaining habitat. For livestock ingredients, the study measured the crop and pasture inputs necessary to produce the meat.
Carrasco said he stopped eating beef about five years ago and the paper’s findings confirmed it was the right step. “I think I will stop eating lamb now, too,” he added. “Even eating sustainably produced beef and lamb means higher demand, and it is not possible to meet global demand with only naturally occurring pasturelands. So it is better to just avoid beef and lamb altogether.”
Joseph Bull, an associate professor of climate change biology at Oxford University, who was not involved with the research, said the findings around legumes and rice having a higher impact in Mexico, Brazil and India were “interesting and add nuance to what we know”, but underlined the fact that the “highest impact foods for biodiversity tend to be meat”.
Michael Clark, a senior researcher in sustainable food solutions at the Oxford Martin School, who was also not involved with the study, said the research “gives a way for people to understand the biodiversity impact of different dishes … [and shows how those] containing ruminant meats such as beef and lamb, or ingredients from tropical regions such as Brazil or India, tend to have high impacts on biodiversity”.
Poor food traceability is another problem highlighted by the study. “If consumers had better ways to identify [the origin of foods] and then make choices, that would help,” Carrasco said.
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