Grow to save the planet

Climate change emissions from meat production are far higher than currently estimated, according to a controversial new study that will fuel the debate on whether people should eat fewer animal products to help the environment.

In a paper published by a respected US thinktank, the Worldwatch Institute, two World Bank environmental advisers claim that instead of 18 per cent of global emissions being caused by meat, the true figure is 51 per cent.

They claim that United Nation's figures have severely underestimated the greenhouse gases caused by tens of billions of cattle, sheep, pigs, poultry and other animals in three main areas: methane, land use and respiration.

Their findings – which are likely to prompt fierce debate among academics – come amid increasing from climate change experts calls for people to eat less meat.

In the 19-page report, Robert Goodland, a former lead environmental adviser to the World Bank, and Jeff Anhang, a current adviser, suggest that domesticated animals cause 32 billion tons of carbon dioxide equivalent (CO2e), more than the combined impact of industry and energy. The accepted figure is 18 per cent, taken from a landmark UN report in 2006, Livestock's Long Shadow.

"If this argument is right," write Goodland and Anhang, "it implies that replacing livestock products with better alternatives would be the best strategy for reversing climate change.

"In fact, this approach would have far more rapid effects on greenhouse gas emissions and their atmospheric concentrations than actions to replace fossil fuels with renewable energy."

Their call to move to meat substitutes accords with the views of the chairman of the UN's Intergovernmental Panel on Climate Change, Dr Rajendra Pachauri, who has described eating less meat as "the most attractive opportunity" for making immediate changes to climate change.

Lord Stern of Brentford, author of the 2006 review into the economic consequences of global warming, added his name to the call last week, telling a newspaper interviewer: "Meat is a wasteful use of water and creates a lot of greenhouse gases. It puts enormous pressure on the world's resources."

Scientists are concerned about livestock's exhalation of methane, a potent greenhouse gas. Cows and other ruminants emit 37 per cent of the world's methane. A study by Nasa scientists published in Science on Friday found that methane has significantly more effect on climate change than previously thought: 33 times more than carbon dioxide, compared with a previous factor of 25.