Friday, April 20, 2007

The truth on greenhouse gases and meat consumption

Last week, Washington Post George Will wrote a sadly uniformed column attacking the public campaigns to reduce greenhouse gas emissions. It drew the usual array of responses and partisan blustering (left, right, ridiculous).

At heart was Time Magazine’s “Global Warming Survival Guide” which featured advice like 51 Tips on Saving the Environment, never mind that global warming is not merely an environmental problem, and that many of the tips have nothing to do with the environment, rather with improving human health.

Tip #22 -- Skip the Steak – claims that livestock is responsible for around 18% of the world’s greenhouse gas emissions. That’s not a mistake. The number comes from a prominent UN report released last year.

What Time, what George Will and what the vast majority of commentators on this subject get wrong is why livestock is responsible for such a large proportion of the world’s GHG emissions.

Columnists and pundits love to joke about cow farts and manure – producing methane and nitrous oxide, respectively – like they’re in bad Adam Sandler movie. That is an important source of GHG. But, in reality, the majority of the emissions attributable to livestock are not coming out the back end, but coming from all the energy used to grow the grain that is fed to livestock.

The United States alone grows almost half of the world’s corn and soybeans. And more than two-thirds of that production is used to manufacture animal feed. It requires an enormous volume of oil, to produce fertilizer and run farm machinery, and an enormous area of land. In turn, it is responsible in part for a number of ecological problems, like the “Dead Zone” in the Gulf of Mexico.

Will seems to mistakenly stumble upon this point, in the midst of some sarcasm, but :

Ben & Jerry's ice cream might be even more sinister [than a steak]: A gallon of it requires electricity-guzzling refrigeration and four gallons of milk produced by cows that simultaneously produce eight gallons of manure and flatulence with eight gallons of methane. The cows do this while consuming lots of grain and hay, which are cultivated by using tractor fuel, chemical fertilizers, herbicides and insecticides, and transported by fuel-consuming trains and trucks.

The concept is right, the comparison is flat wrong. Producing a gram of dairy protein requires only a fraction of the energy of producing a gram of meat protein, especially beef (for the simple reason you don’t kill the cow every time you milk it).Of the feed produced in the United States, only 12% is devoted to dairy cattle (see here). The rest goes to beef cattle, poultry and pork production. That’s why you often hear claims that we should all eat less meat, but not less dairy.

In essence, this problem is not about meat consumption. It is about devoting a significant proportion of our energy and our land to produce meat. One of the biggest obstacles to reducing greenhouse gas emissions in the future will be diet. We may or may not be exporting democracy to the world, but we certainly are exporting our meat-rich diets. As meat consumption rises in China and other parts of the developing world, the challenge of reducing oil consumption and reducing greenhouse gas emissions will grow. More on that later.

1 comment:

Craig Mackintosh said...

You got the truth there Simon. Keep it coming. :)