Nicholas Stern, author of the influential 2006 Stern Review on the cost of tackling global warming, said methane emissions from cows and pigs are 23 times more powerful than carbon dioxide as a global warming gas, The Times of London reported Tuesday.
"Meat is a wasteful use of water and creates a lot of greenhouse gases," Stern told the newspaper. "It puts enormous pressure on the world's resources. A vegetarian diet is better."
He said higher prices for meat and other foods that generate large quantities of greenhouse gases would result from a successful deal to reduce greenhouse gases at the December Climate Change Conference in Copenhagen.
"I think it's important that people think about what they are doing and that includes what they are eating," Stern told the Times. "I am 61 now and attitudes towards drinking and driving have changed radically since I was a student. People change their notion of what is responsible. They will increasingly ask about the carbon content of their food."