The Lancet said reducing global red-meat consumption by 10 per cent would reduce the animal gases that contribute to global warming. With world demand for meat increasing, however, experts fear increased livestock production will mean more methane and nitrous oxide heating up the planet.

In China, for example, people are eating double the amount of meat they used a decade ago.

Other ways of reducing greenhouse gases from farming, like feeding animals higher-quality grains, would only have a limited impact on cutting emissions, leaving reduced demand for meat as the only viable option.

The amount of meat eaten varies considerably. In developed countries, people typically eat about 224 grams per day. In Africa, most people only get about 31 grams a day. A Lancet author said if the global average were 90 grams per day, that would prevent the levels of gases from speeding up climate change.

It would also help corral obesity.