critique and commentary on world energy news…

Cows eating... Grass! (Source: http://www.uky.edu/Ag/PAT/recs/livestk/livestk.htm)

Lately it seems that the livestock industry, particularly cattle have been getting some negative publicity. One of the latest articles on this topic, Greening the Herds: A New Diet to Cap Gas from the New York Times highlights the contribution of cattle ranches to world greenhouse gas emissions and a new effort at US dairies to decrease emissions. The article includes gross, but sobering information about exactly how cattle contribute to global climate change by stating that “the average cow expels — through burps mostly, but some flatulence — 200 to 400 pounds of methane a year.” It seems that bovines haven’t always had digestive difficulties, though; the excessive emissions from cows are the result of the grain based diet they are fed. Cows evolved to consume a grass based diet, which is why they are less healthy consuming grains and produce so much methane.

Concern over the gaseous emission from cattle has escalated in light of the United Nation’s prediction that beef and dairy production will double worldwide in the next 30 years and a 2006 study that “estimated that cows might be more dangerous to Earth’s atmosphere than trucks and cars combined.” In response to concerns over bovine emissions, the dairy industry (which accounts for only 2% of greenhouse gas emissions in the US) has decided to decrease its emissions by 25%. How do they plan to do this you may ask? Well, they are using all sorts of biological tricks such as genetic modifications to make cattle that burp less, altering the bacteria in the animal’s guts, and modifying their diet so it more closely resembles the grasses they evolved to eat. A dairy in Vermont is giving diet modification a try by using a feed mix that European cattle already consume to cut emissions.

Now, these efforts are admirable, but I feel that they are all circumventing the heart of the problem:

1)      Cattle are being fed the wrong food

2)      There are too many cattle on the wrong diet and there are soon to be more

Don’t get me wrong, I am not a vegetarian and I realized long ago that trying to deny people a juicy steak would probably be the equivalent of denying them electricity and running water, but this problem is undeniably rooted in the scale of the modern livestock industry. The US alone holds about 80 million animal units (an animal unit is equal to 1000 lbs of live animal) of dairy and beef cattle. Genetically modifying cattle and giving them fancy new feeds cannot contain the problem if consumption of cattle products still increases, as the U.N. predicts. In addition, cattle contribute to a long list of other environmental hazards such as the energy intensity of modern livestock production, water quality, and air quality. Not to mention a whole list of health complications connected to excessive meat consumption. The overall environmental and health hazards of beef and dairy production has its roots in our demand for these products. I won’t expand any further on this topic, I believe that the question of demand is up to the individual and requires personal reflection.

Now, back to my first point: cattle are being fed the wrong food. I was amazed to hear that the solution to the problem of the unnatural diet of modern cattle was solved by adding flax seed, alfalfa and supplements to their grain diet that “mimic the spring grasses that the animals evolved long ago to eat.” Hmmm… my question is: Why don’t they just give them the grasses?

Another source of greenhouse gas emissions that this article didn’t mention comes from cow’s decomposing manure. Emissions from livestock manure can be cut by anaerobically digesting the waste to produce biogas and using the biogas to generate electricity and displace fossil fuel fired electricity generation. Usually livestock operations will either store the manure in a lagoon (which emits methane, a gas with 21 times the global warming potential of carbon dioxide) or leave it out in the open to decompose; this method emits nitrous oxide, which has 310 times the global warming potential of carbon dioxide. Besides emitting potent greenhouse gases, livestock manure also emits toxic air pollutants (ammonia, particulate matter, NoX and others), can run off into surface water or contaminate ground water (some areas experience algal blooms in their potable water reservoirs due to run-off, tastes yummy!). Biogas production eliminates many of these problems. Most large cattle operations already gather and store manure in one of these two ways, which makes a switch to biogas production much easier.

Yes, that is a huge pile of cow manure on fire. (source: http://www.cbsnews.com/stories/2005/01/28/national/main670076.shtml)

Bottom line: Modern beef and dairy production methods pose a hazard to the environment in the form of greenhouse gas emissions and pollution in general. The problem (of greenhouse gas emissions at least) is rooted in the scale of the modern cattle industry and the grain based feed that constitutes their diets. Let us not forget this when coming up with solutions: a grass based diet, rethinking our demand for beef and dairy, and making better use of manure.