All animals emit greenhouse gases and by comparison, humans are relatively restrained respirators. The planet's livestock animals alone, for example, breathe out three billion tonnes of CO{-2} a year. Livestock, indeed, emit more GHG into the atmosphere than all of the cars, freight trucks, railways, airplanes and container ships in the entire world.

In a comprehensive 400-page analysis, published last year, the UN's Food and Agriculture Organization (FAO) described the spiralling increase in greenhouse gases from livestock as "massive" and asserted that the world governments must urgently address the problem. It explicitly chided environmentalists for their apparent indifference. In essence, the FAO says, livestock have inherited the Earth - with disastrous consequences.

Together, livestock animals account for 20 per cent "of terrestrial animal biomass" - in other words, of all living land creatures, humans included. Feed crops take 30 per cent of the world's arable land. Livestock command 70 per cent of the planet's agricultural land and 30 per cent of its entire land surface.

Directly and indirectly, livestock account for 18 per cent of greenhouse gas emissions - more than "all transport" combined. These animals emit 9 per cent of human-induced carbon dioxide, 37 per cent of human-induced methane, 64 per cent of human-induced nitrous oxide and 65 per cent of human-induced ammonia.

Animal husbandry, the FAO finds, "is responsible for the production of gases with far higher potential to warm the atmosphere than carbon dioxide." These gases cause other problems as well. Though measured in the atmosphere in parts per billion, nitrous oxide can overwhelm forests, producing what the FAO calls "forest dieback." The excessive nitrogen load essentially reverses the growth effect of CO2 and reduces the capacity of the forests to act as "carbon sinks."

Livestock gas, as bad as tranport emissions

Economic growth in developing countries has driven the world's recent increase in meat production, and the higher the income, the bigger the steaks tend to be. Canadians and Americans consume almost 100 kilograms of meat, per capita, per year (which requires the killing of 10 billion animals). The Chinese account for 60 per cent of the world's increase in meat production in the past 25 years. Meat consumption increased by 30 per cent in China's cities between 1980 and 2000 and by 85 per cent in China's rural areas. The Chinese are now the world's biggest producer of pork and, necessarily, the world's biggest producer of methane gas from pig manure.

The FAO report ("Livestock's Long Shadow") says that livestock "biomass" increased from 428 million tonnes in 1960 to 700 million tonnes in 2000. Aside from the three billion tonnes of CO{-2} that result from simple breathing, this vast herd of creatures emits 85 million tonnes a year of intestinal methane and 18 million tonnes of manure methane.

Greenhouse gas emissions from beef, pork and chicken are every bit as human in origin as the emissions from cars and trucks - and every bit as serious.

Source:theglobeandmail.com