Such an agreement would be in line with findings by focus groups in the United States, China, Brazil and the United Kingdom, which indicate that governments should urgently address unsustainable meat consumption (see go.nature.com/2asd1ag). In industrial agriculture, cereals that are edible to humans are fed to animals for conversion into meat and milk. This undermines our food security: rearing livestock is efficient only if the animals convert materials we cannot consume into food we can eat. That means raising them on extensive grasslands, rotating integrated crop-livestock systems and using by-products, unavoidable food waste and crop residues as feed.
Feeding animals exclusively on such materials would greatly reduce the availability and hence the consumption of meat and dairy products, as well as the use of water, energy and pesticides — thereby cutting greenhouse-gas emissions.