February 15, 2009
First published in Common Ground Magazine
I am not a meat eater. I have been vegetarian all my adult life, simply because I don’t want to contribute to the suffering and killing of animals that are raised for meat.
I still consume milk and cheese so I have to acknowledge that I’m still a cause of the cruelty associated with the dairy industry, where the cows’ male calves are taken away from them at birth and raised in tight crates, before being killed for veal (see www.noveal.org).
The matter that concerns me here is the impact of animal farming on global warming. This has been the quiet taboo that most climate scientists and activists don’t want to talk about. One prominent scientist publicly scolded me for even raising the topic. He said it was hard enough getting people to cut back on driving, let alone asking them to stop eating meat.
During 2007, awareness that the livestock industry was part of the problem took a leap forward with the release of the UN report Livestock’s Long Shadow, which teases apart the many ways in which cattle, sheep and pigs are a cause of global warming.
It starts with the production of nitrogen fertilizers for use on livestock feed crops. This uses five percent of the world’s natural gas, producing 40 million tonnes of CO2 a year.
Next, there’s the use of fossil fuels for heat, machinery, irrigation, drying, etc, at 90 million tonnes.
A third factor is the burning of forests to grow feed for livestock, especially in Latin America. This is a big component, releasing 2.4 billion tonnes of CO2 a year. Cattle that graze on open pastures are not off the hook; the desertification that grazing causes produces 100 million tonnes.
Then there is the reality that cows have four stomachs. Without oxygen, their food ferments and they burp methane; that traps 25 times more heat than CO2 over 100 years (up to 100 times as much over 12 years, the natural life of methane). Buffaloes, sheep, goats and camels also burp methane. Pig and cow manure releases another 200 million tonnes. Measured as CO2 equivalent (CO2e), it comes to 2.2 billion tonnes.
Finally, we come back to nitrogen. When nitrogen fertilizer is applied to the land wastefully, it is not all absorbed by the soil, but escapes as nitrous oxide (N2O), a greenhouse gas that traps 298 times more heat than CO2 and persists in the atmosphere for up to 150 years. It is also released by animal manure. All told, livestock’s N2O emissions produce a further 2.2 billion tonnes of CO2.
When you total it up, it comes to 7.1 billion tonnes, or 18 percent of the 40 billion tonnes of CO2e that humans produce each year – more than all the world’s transport.
I am rewriting my book on solutions to global warming and when I crunched the numbers I got the astonishing result that eating beef adds 4.6 tonnes to an individual’s yearly emissions of CO2e – more than a year’s driving in an average car. A kilogram of beef produces 90 kg of CO2e. If true, a ¼ pound single hamburger is responsible for 9 kg of emissions – the same as driving 20 to 25 miles.
I should state that my results are still in the interim stages. The Greenpeace report Cool Farming suggests 13 kg of CO2 per kg of beef, 17 kg per kg of lamb. A 2007 Japanese study suggested 36.4 kg of CO2 from a kg of beef. For determined meat-eaters, a 2003 Swedish study concluded that organic beef, raised on grass, produces 40 percent less CO2e. It is also far healthier since it contains good Omega 3 fatty acids, instead of the harmful Omega 6.
Whatever the final numbers, the conclusion is clear. Cutting right back on our consumption of meat and dairy must be an essential part of any strategy to tackle global warming.
But don’t mourn – I can assure you that good veggie food tastes delicious and is far better for your health. You’ll even live longer. Not a bad trade-off!