I've been unable to withstand the nagging pressure of a close friend to watch the "Cowspiracy" documentary. I gather this film has managed to turn numerous people toward veganism, which is pretty impressive. My one or two readers must be dying to know whether the presentation will have turned me away from tenderloin. The answer is no. The better question is why. For that, read on.

One can see why the film is compelling. Snazzy graphics, high production values, dramatic numbers, earnest assertions throughout, and a chance to be a hero and save the world. Surely the filmmaker wouldn't exaggerate or mislead. Only a cynic would look for mistakes.

This is that place.

Some disclaimers up front. I'm just a reasonably technical guy with a fondness for skepticism and analysis. I don't have special expertise in agriculture, climate science, and am not about to fact-check every little claim. I don't have the time or inclination. It's not my place to pass judgement on people who find the film convincing. I only posit a few reasons to be cautious in taking everything in it at face value.

The film has a few broad claims about animal agriculture that underpin it. Let's address those.

  1. greenhouse gas emission

    The film's first complaint against the beef industry is its supposedly large contribution to greenhouse gas emissions, which are said to endanger the planet along the global warming lines. This is done by reference to the amount of methane (CH4) produced by cows directly and/or from manure. It is compared to CO2 etc. produced from burning fossil fuels.

    But there is a fatal flaw in this comparison. In a way, it ignores the law of preservation of mass. It pretends that carbon flow is only one way: leaving the cow. That "one way flow model" may be a reasonable way to think about fossil fuels (where carbon is leaving the deep underground, and staying up), but that's not how cows work. For one thing, cows eat. In fact, I have it on good authority that every atom of Carbon that ever leaves the cow first entered the cow through its food.

    So what? It means that the cow is a pure carbon recycler, not a carbon source. It does not contribute net to greenhouse gases, because the foods it eats took just as much carbon out of the environment (mostly air) as the cow later exhausts. And the same for every other animal. You don't have to feel bad for breathing out CO2 - you first ate the same amount.

    The only net carbon flow into the atmosphere comes from the fossil-powered machinery involved in the process. (Let's not quibble about NH4 vs. CO2 vs. H2O's relative greenhouse effect strengths.)

  2. water consumption

    The filmmaker returns to water consumption time after time after time with claims like "it takes XXX gallons of water to produce YYY pounds of beef". The numbers shock, but only out of surprise. The filmmaker mentions drought conditions in California and contrasts them to those water-usage amounts.

    There are at least two separate errors there. The first is the same error as done for greenhouse gases. Water flows not only into the cow but also out - and in very close to the same amount. (If one is talking about water that goes into irrigating the plants for the animal feed, that will chemically change into sugars etc. for a while. But when digested, it goes back to water form.) Sure, most of it is pee rather than lovely drinkable water, but that is a small difference. Yes, cleaning water takes some resource and/or time, but the cow's drinking water does not disappear! It gets recycled. Similarly, the overall water output and input of a town is about the same.

    The other error is treating California human water as interchangeable to cattle drinking water. But it's very much not interchangeable. Most importantly, cattle are not grown in drought areas! Cattle farms are located where water is abundant. That water is simply not available to thirsty Californians thousands of miles away! Closing every animal farm in the world won't put one extra pint of water into California taps.

  3. sustainability

    This word is in the title of the film. It is thrown around by the filmmaker in rhetorical questions to interviewees, as in "that's not very sustainable, is it?". The term is never actually defined! This is a problem. The literal meaning is of course "able to be sustained", in the time-wise sense. So something is sustainable if it can continue. Because "sustainable" is a relative adjective, it is simply meaningless without context. And one can cherry-pick the time interval of interest and say ... of course animal agriculture is "sustainable" since it has already been sustained for thousands of years and will be sustained until tomorrow at the least.

    One pseudo-meaning that the filmmaker sometimes invents is "extrapolation to every human being". ("What if every person eats as much meat as an American?") It would be more proper to call this property is "scalability", and frankly it's unconvincing. There is no reason to assume that the rest of the world should emulate Americans. They're certainly far away in terms of per-capita GDP (productivity), so couldn't afford it in the first place. There's nothing wrong with that.

    The other affront is the presumption that "sustainability" in any sense is necessary. The universe is not static. People change, seasons change, the climate changes. There is no need for any situation to be "sustainable" across any span of time. If some product or service is OK here and now, but not sustainable in a different context, it will be naturally discontinued (because its costs or its value will make it uneconomical). One of the farmers phrased it well: "sustainable is profitable". Once it stops being profitable, the product/service will not be sustained.

The filmmaker posits that there is a conspiracy amongst environmental groups in neglecting to talk about animal agriculture. The logic / scientific errors analyzed above give us another possible explanation: because it is not necessary to worry about non-problems. I'm hoping that the filmmaker was honest, merely mistaken, rather than deliberately misleading.

The film did make several quite reasonable points. The on-screen slaughter of a duck and a half, the compassionate playing with other animals, must have been designed to arouse normal affection toward animals. One would have to be quite jaded not to feel like petting the average peaceful cow. I fully grant that wanting to avoid killing for ethical or emotional reasons is a completely valid value position. The possibility of healthy living with a purely vegan diet is plausible. I respect people who make that choice.

I just wish people made that choice for such value reasons, instead of being mislead by a film of shoddy logic & science.