Sunday, September 7, 2008

Meat Eating and Global Warming- Food for Thought.



The BBC reported today that Rajendra Pachauri, chairman of the UN Intergovernmental Panel on Climate Change (IPCC) is set to speak tomorrow evening in London about the environmental impact of meat eating. The UN Food and Agriculture Organization estimates that direct greenhouse gas emissions from meat production account for about 18% of the world’s total emission. As such, meat production puts more greenhouse gases into the atmosphere than transport (which accounts for 13% of the world’s greenhouse emissions).

The figure represents the emissions released from all part of the meat production cycle: clearing of forested land, making fertilizer, transport and use of farm vehicles and methane emissions from the cattle and sheep.

Dr. Pachauri stated “...I want to highlight the fact that among options for mitigating climate change, changing diets is something one should consider.”

According to The Consumer’s Guide to Effective Environmental Choices, about 800 million acres, or 40% of US land area, is used for raising livestock. 60 million acres of land is additionally used to grow grain to feed the livestock. This land use evidently reduces the land available to support natural wildlife. In fact, household meat consumption alone is responsible for about a quarter of threats to natural ecosystems and wildlife.

A typical cow raised for slaughter will convert 32 lbs of grain into 4 lbs of weight. That’s a lot of grain, considering a typical steer weighs 1100lbs at the time of slaughter. In fact, 60% of the corn that’s grown in the US goes to feeding livestock. This grain requires a lot of synthetic fertilizer- over 100lbs per acre. Some of this fertilizer (ammonium nitrate) evaporates into the air where it’s transformed into nitrous oxide, an important greenhouse gas. A lot of it runs off into our waterways, potentially harming our health and poisoning the marine ecosystem. Nitrogen stimulates algae growth creating a hypoxic ‘zone’ that is as big as New Jersey in some areas, killing all the wildlife.

According to Michael Pollan, author of The Omnivore’s Dilemma, petroleum is the most important ingredient in the production of modern meat. The food chain responsible for raising the meat that ends up on your plate is fossil fuel driven. According to Pollan, a typical steer will have consumed the equivalent of 35 gallons of oil in his lifetime. Bon App├ętit!

Other environmental impacts of meat consumption include a drain on water resources- 18% of total drinkable water use is attributable to livestock raising. Animal waste is a huge problem- about 2 billion tons of manure is produced a year. Not only is this manure responsible for emitting an estimated 150 trillion quarts of methane gas into the air yearly (methane being the second most significant contributor to the greenhouse effect behind carbon dioxide), but it’s also responsible for about 16% of common water quality problems and its runoff into our waterways is a serious threat to that ecosystem.

Dr. Pachauri recommend that meat eaters aim to give up meat for at least one day a week, and continue decreasing from there, to minimize their carbon footprint. Moreover, a 2003 Swedish study found that organic beef, raised on grass rather than grain, emits 40 per cent less greenhouse gases and consumes 85 per cent less energy. Moreover, choosing locally raised beef reduces the amount of transport involved. These represent better environmental choices. Researchers are doing their part by genetically engineering strains of cattle that will produce less methane gas.

Sources:

“Shun Meats, says UN climate chief”. http://news.bbc.co.uk/2/hi/science/nature/7600005.stm

“Meat is Murder on the Environment”. http://environment.newscientist.com/article/mg19526134.500-meat-is-murder-on-the-environment.html

“Eat Less Red Meat to Help the Environment, UN Climate Experts Says.” http://www.telegraph.co.uk/news/uknews/2699173/Eat-less-red-meat-to-help-the-environment-UN-climate-expert-says.html

Brower M, Leon W. The Consumer’s Guide to Effective Environmental Choices: Practical advice from the union of concerned scientists”. NY: Three Rivers Press. 1999. http://www.amazon.com/Consumers-Guide-Effective-Environmental-Choices/dp/060980281X

Pollan Michael. The Omnivore’s Dilemma: A natural history of four meals. Penguin Books. 2006. http://www.michaelpollan.com/omnivore.php

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2 comments:

Jme said...

your blog is awesome. im glad you keep it up to date cause i find it really interesting.

Sybil Hebert, RD said...

aww. thanks jme. that means a lot.