People in the rich world should become "demitarians" – eating half as much meat as usual, while stopping short of giving it up – in order to avoid severe environmental damage, scientists have urged, in the clearest picture yet of how farming practices are destroying the natural world.
They said the horsemeat scandal had uncovered the dark side of our lust for meat, which has fuelled a trade in undocumented livestock and mislabelled cheap ready meals.
"There is a food chain risk," said Professor Mark Sutton, who coined the term demitarian and is lead author of a UN Environment Programme study published on Monday . "Now is a good time to talk to people about this."
The quest for ever cheaper meat in the past few decades – most people even in rich countries ate significantly less meat one and two generations ago – has resulted in a massive expansion of intensively farmed livestock. This has diverted vast quantities of grain from human to animal consumption, requiring intensive use of fertilisers, pesticides and herbicides and, according to the UNEP report, "caused a web of water and air pollution that is damaging human health".
The run-off from these chemicals is creating dead zones in the seas, causing toxic algal blooms and killing fish, while some are threatening bees, amphibians and sensitive ecosystems.
"The attention this meat scare has drawn [highlights] poor quality meat. It shows society must think about livestock and food choices much more, for the environment and health," said Sutton.
The answer, Sutton said, was more vegetables on the plate, and less animal protein. "Eat meat, but less often – make it special," he urged. "Portion size is key. Many portions are too big, more than you want to eat. Think about a change of culture that says, 'I like the taste, but I don't need so much of it.'"
By filling plates with vegetables as well as the meat, people will be better nourished. "Most people don't notice," he said, citing a recent UN event at which the chef used a third the amount of meat, more vegetables to make up for it, and more than 90% of guests were just as satisfied.