"United we bargain, divided we beg."

Friday, February 20, 2009

Ethical Eating and "Carbon-Costly" Meat

I came across this article today (below, edited), which covers a report given on the carbon footprint of producing various types of meat. No surprise that beef is the big bad guy, but there is a huge surprise here: the lead researcher says that grass raised beef has a higher carbon footprint than grain finished meat. Apparently, that's because the animals take longer to get to market weight and fart more methane while doing so. I'm not fully convinced, as there are many unanswered questions in the article: does the calculation take into account the carbon cost of growing, fertilizing, and shipping the grain? Does it include the cost of shipping hundreds of thousands of cattle to the feedlot? 
And of course carbon isn't the only consideration in the world here; there's the enormous destruction wreaked on water resources by CAFO's (feedlots). There's the millions of tons of concentrated excrement from a CAFO to be disposed of. There's the question of antibiotic resistance caused by the massive dosing of feedlot cattle with antibiotics to keep them alive long enough to kill. There's the issue of animal suffering, which they most surely do spending their last weeks in filthy, extremely crowded conditions. 
The report eventually comes to the conclusion that people who truly want to reduce the carbon cost of their food should switch some of their meat consumption to other, less costly meats. Pork is only about one fourth as carbon-costly (like my new term?) as beef, and chicken one tenth. Then of course there's the logical solution: simply eat less meat altogether. 
In this report, near the end, there's a figure that states a grown human needs no more than 53 kilos of meat/year to maintain optimum health. That'll be news to all the optimally healthy vegetarians out there, but let's let it alone for the moment. Our quarter steer weighed about 200 pounds. That's 91 kilos. Divide by three adults in the family and we get 30 kilos per person per year. Then there's the 50 kilo pig we eat each year, that adds 15 kilos/person. And an unknown number of chickens, and assorted fish. Hmm, I'm going to guesstimate that each adult in our family eats between 65 and 75 kilos of meat per year.  That's a lot of meat, but not really for an American. 
And no, folks, no way am I giving up my pasture raised beef from across the street. Even if these guys are right, I'm not participating in the CAFO system, I'm not eating an inferior, hormone and drug laced product, I'm supporting my neighbor's farm, and I'm going to darn well enjoy my beef with it's zero food miles. 

The carbon footprints of raising livestock for food
Web edition : Sunday, February 15th, 2009
font_down font_up Text Size

THE FIRST OF TWO PARTS. Followup story is at:http://www.sciencenews.org/view/generic/id/40943/title/AAAS_Climate-Friendly_Fish

For the good of the planet, we’re all being asked to reduce our carbon footprints — the quantities of greenhouse gases, aka GHGs, associated with our actions. Since some 30 percent of the global warming potential attributable to society’s GHG emissions stems from the production of foods and beverages, menu choices are critical, noted Ulf Sonesson of the Swedish Institute for Food and Biotechnology in Goteborg, today. From this climate perspective, meat eaters are the big hogs.

Sonesson was one of the speakers on a panel titled “Food for Thought” at theAmerican Association for the Advancement of Science annual meeting. This morning’s speakers shared data from largely new analyses on how foods, production techniques, and transportation affect the climate costs associated with our dining choices. And there were some big surprises.

No longer a surprise is the relative energy intensity associated with meat, especially beef. For instance, roughly half of the GHG emissions due to human diets come from meat even though beef, pork and chicken together account for only about 14 percent of what people eat.

From a climate perspective, beef is in a class by itself. It takes a lot of energy and other natural resources to produce cattle feed, manage the animals’ manure (a major emitter of methane, a potent GHG), get the livestock to market, slaughter the animals, process and package the meat, dispose of the greater part of the carcass that won’t be human food, market the retail cuts, transport them home from the store, refrigerate them until dinner time, and then cook the beef.

Tally the GHG emissions associated with all of those activities, Sonesson says, and you’ll find it’s the global-warming equivalent to spewing 19 kilograms ofcarbon dioxide for every kg of beef served. Swine are more environmentally friendly. It only takes about 4.25 kg of COto produce and fry each kg of pork. At the other end of the spectrum are veggies. The climate costs associated with growing, marketing, peeling and boiling up a kg of potatoes, by contrast, is just 280 grams, Sonesson reported.

Another factor contributing to cattle’s particularly egregious carbon footprint is their relative fecundity, if you will, says Nathan Pelletier of Dalhousie University in Halifax, Nova Scotia. In her lifetime, a mother fish, particularly in protected aquaculture settings, may give birth to hundreds — if not thousands — of surviving offspring. A hen could certainly produce hundreds of chicks. Even a sow can give birth to eight piggies per litter. But a cow: She tends to issue a single calf every year for maybe 10. And while she’s in gestation and then waiting to become pregnant again, farmers have to care for her and perhaps a bull — which are both big, hungry manure factories.

Many environmentalists have argued that finishing up the fattening of beef cattle on corn is worse for the environment than cattle that are raised solely on pasture grass. Pelletier says his team’s analysis finds that at least from a climate perspective, the opposite is true. “We do see significant differences in the GHG intensities [of grass vs grain finishing]. It’s roughly on the order of 50 percent higher in grass-finished systems.”

When an audience member questioned whether he had heard that right, that grass-fed cattle have a higher carbon footprint, Pelletier reiterated, “higher. Yes.” The reason: “It’s related to the much higher volumes of feed throughput and associated methane and nitrous-oxide [GHG] emissions.” He added that most pastures were highly managed, and subject to “periodic renovations and also fertilization.” Finally, with grass-fed cattle “there is also a high [grass] trampling rate. So the actual land area that you need to maintain magnifies that [GHG] difference,” Pelletier said.

But what really concerns his team about the bonus GHG emissions linked to beef is the planet’s growing numbers — and appetite for meat.

Currently, although beef accounts for only about 30 percent of the world’s meat consumption, it contributes 78 percent of meat’s GHG emissions. Pork, at 38 percent of consumption, contributes only 14 percent of meat's GHGs. Another 32 percent of the meat consumed worldwide comes from chicken, but getting these birds from farm to fork contributes only 8 percent of meat’s global carbon footprint. By shifting some share of beef and pork production to chicken over the next four decades, the increase in meat’s GHG emissions by 2050 might be held to just 6 percent higher than today, Pelletier said, even as the human population grows by another quarter-million each day.

Although meat's overall carbon footprint is projected to grow only a little over the next 40 years, the global goal is to cut emissions in every sector. Pelletier offered some suggestions on how to do that. Some were considerably more appetizing than others.

For instance, substituting all beef production for chicken would cut meat’s projected carbon footprint by 70 percent, he said. Or perhaps per capita intake of meat could drop from a current average of 90 kilograms per year in the developed world to the 53 kg per person per year that's been advocated as sufficient for human health by the U.S. Department of Agriculture. Under this scenario, Pelletier said, “I estimate that . . . we could reduce associated [carbon] emissions by roughly 44 percent.”

Swap half of that protein now supplied by meat with soy by 2050, and “you could expect [projected] emissions to decrease on the order of 70 percent,” he said. Take the next big step — eliminating all meat in favor of soy — should drop the protein-associated carbon footprint of Western diets a whopping 96 percent.

Pelletier described that the last scenario as “utopian.” Hmmm. Not for this carnivore. I’m willing to eat chicken much of the time and reserve beef as a big treat — maybe even to be downed only in small portions. But go solely soy? That’s no utopia to me.

That said, would I consider such a sacrifice for survival of the planet? Of course — but I’m hoping someone can shoot me recipes that would made this legume taste like something other than soy. So far I only have one, but it's dynamite: forchocolate mousse pie.

Next up: What about fish?


ChristyACB said...

I followed the links. Very interesting.

Where I think the disconnect between what smallholders like you and others in our Homesteaders style of life do and the type of grass feeding the science is based on is land use and volume.

For people with a small bit of land that graze a cow and use the grass fed beef, that land is usually not "highly managed" and rather natural, with a low trample rate and having the cow actually eliminates carbon use normally required for much maintenance.

Beef is still going to be higher carbon per pound than chicken, yes, but smallholder grass fed is a very different thing that he was researching I think.

You think so?

Aimee said...

well, having lived across the street from the man I buy my grass-fed beef from for two years now, I can say with a pretty high degree of certainty that it isn't highly managed land. He has 120 acres, and probably 40 or 50 head of cattle. He rotates between at least three pastures, and I've never - never - seen any machinery out there besides once a year when he hays the fallow fields. I haven't ever walked his fields, so I can't say anything about plant diversity or wildlife (oh wait yes I can - bald eagles raised a chick on his property last year) but it looks pretty green from over here. certainly there aren't any obvious bald spots or compaction. He's been in the same spot for over fifty years, so I guess he's managing his land pretty well.