Last Updated: 2:59am BST 19/07/2007
Producing 2.2lb of beef generates as much greenhouse gas as driving a car non-stop for three hours, it was claimed yesterday.
Japanese scientists used a range of data to calculate the environmental impact of a single purchase of beef.
Taking into account all the processes involved, they said, four average sized steaks generated greenhouse gases with a warming potential equivalent to 80.25lb of carbon dioxide.
This also consumed 169 megajoules of energy.
That means that 2.2lb of beef is responsible for greenhouse gas emissions which have the same effect as the carbon dioxide released by an ordinary car travelling at 50 miles per hour for 155 miles, a journey lasting three hours. The amount of energy consumed would light a 100-watt bulb for 20 days.
Most of the greenhouse gas emissions are in the form of methane released from the animals' digestive systems, New Scientist magazine reported.
But more than two thirds of the energy used goes towards producing and transporting cattle feed, said the study, which was led by Akifumi Ogino from the National Institute of Livestock and Grassland Science in Tsukuba, Japan.
Su Taylor, the press officer for the Vegetarian Society, told New Scientist: "Everybody is trying to come up with different ways to reduce carbon footprints, but one of the easiest things you can do is to stop eating meat."