Most people looking to reduce their contribution to global warming think about taking fewer car journeys or replacing a gas-guzzling 4X4 with a smaller runabout. Few would consider cutting their meat consumption - but one authority on climate change has suggested we do just that. Rajendra Pachauri, the chairman of the Intergovernmental Panel on Climate Change, has said that meat production contributes close to one-fifth of greenhouse gas emissions.
Dr Pachauri, a vegetarian, told media recently that cutting meat consumption was "something one could consider" to help the planet. Initially, he suggested people should give up meat for one day a week before trying to make further cutbacks. His calls are echoed by Joyce D'Silva, ambassador for a UK pressure group called Compassion in World Farming. Ms D'Silva says when four members of a family each have a quarter-pound beef burger, they create as large a quantity of greenhouse gases as a 100km car journey, when the contribution made by the production of the meat is taken into account.
It is beef production that concerns environmentalists most, partly because cattle generate large quantities of methane through their wind and manure. In fact, more than one-third of the world's methane, which is 20 times as damaging as carbon dioxide in terms of global warming, is said to be produced by cattle, including those used for milk. The animals release the gas constantly because of the bacteria in their gut that help them to digest cellulose, the carbohydrate that makes up much of the cell wall of plants.
A report released in 2006 by the United Nations' Food and Agriculture Organisation (FAO), titled Livestock's Long Shadow, detailed a host of other environmental concerns. Two-thirds of global emissions of ammonia, which causes acid rain, are said to be produced by livestock, while hormones used to help the animals grow faster can pollute drinking water. According to Ms D'Silva, beef production is particularly inefficient when it comes to the use of resources.
It takes 7kg to 10kg of feed to produce 1kg of beef, she says, compared with just 2kg of feed to produce the same quantity of chicken. "Actually, one third of the world's cereals and 90 per cent of the world's soya goes to animal feed rather than human food. It's not a good way to use up the world's scarce cereal grains," Ms D'Silva says. Cattle ranching and soya production to feed cattle often take place on deforested land, and this deforestation is thought to be the most significant way in which meat production contributes to global warming.
In addition, large amounts of carbon dioxide are generated by the transportation involved in meat production and in the production of fertilisers used to grow animal feed. Overall, the FAO blames the meat industry for nearly 10 per cent of global carbon dioxide. According to Ricardo Uauy, Professor of Public Health Nutrition at the London School of Hygiene and Tropical Medicine, average daily meat consumption around the world should be cut from 100g now to 90g by 2050.
This reduction is necessary, he says, just to stabilise emissions as the world's population continues to grow and more people start eating. At present, Professor Uauy says, meat consumption varies wildly around the globe, with some countries such as Argentina getting through 300g per person each day while in others an average of just 20g is consumed. If the biggest meat-eating nations cut back significantly, Prof Uauy believes, it would allow developing countries to increase the amount they eat to "sustainable" levels.
"There should be a decrease in the rate of rise [of meat-eating in developing countries] and a ceiling of 80 to 90g," he says. Prof Uauy says this would lead to health, as well as environmental, benefits, because studies with red meat indicate that consuming more than about 60 to 90g per day can increase the risk of colon cancer. In fact, apart from very young children, Prof Uauy insists people can easily live healthily without eating meat at all.
"There is nothing in meat that makes it essential," he says. "Other foods provide protein and iron. The most appropriate ones are legumes and beans. "In the Middle East, maybe rice with lentils and chick peas is good. That's the way we've eaten for ages, with just small amounts of meat." As for those who do not want to give up their meat completely, Prof Uauy believes they should consider switching from beef to other forms of meat, such as chicken, that have "much less" of an impact on the planet because the animals require smaller amounts of feed per kilogram of meat.
"The idea is that in the case of beef, [consumption] should be lower. There are more effective ways of getting animal protein. It's disproportionate in terms of what you put in," he says. Prof Uauy himself tries to eat beef only once a week and as a result he allows himself a slightly more generous portion when he does actually tuck in. "From the standpoint of colon cancer, there's a benefit from having it less often. It's not just the total amount, but also the frequency," he says.
However, greenhouse gas emissions from the beef industry could decline even if consumption fails to decline, thanks to new technologies being developed. Scientists in Australia and New Zealand have created a grass that causes cows to produce less methane. The genetically engineered grass suppresses an enzyme and this in turn makes the grass more digestible. Some experts have suggested that the overall effect could be to increase the amount of methane produced by each cow, although milk production is improved. This means that the quantity of methane generated per litre of milk declines.
In the UK, the government's Department for Environment, Food and Rural Affairs aims for close to one third of the country's milk producers to be trying out low-methane technologies within seven years. Prof Uauy is sceptical about the potential for technology to reduce the contribution of cattle to global warming. "The issue is that you have animals that are, by definition, ruminants - they take up grass and ferment it. That's where methane comes from," he says.
"You can make animals consume corn instead but then you make it harder [on the environment] because you have to produce the corn." dbardsley@thenational.ae