Ruth Notes: The Winds of Change, Part ll

Last Meatless Monday, we looked at the impact of cattle on global warming/climate change, and asked two questions: 1) if cattle do so much harm to the ozone layer through their methane-laced flatulence, why didn't the millions of buffalo that existed hundreds of years ago destroy the environment back then? and 2) why does the finger always get pointed at beef cattle, but not diary cows, when these lethal bovine farts are discussed?

No, because there just aren't enough of you compared to beef cattle. As a side note, there aren't just fewer dairy than beef cattle now, there's fewer dairy cows than there have ever been; 13 million fewer cows than than there were in 1950, to be exact. Between 1960 and 1990, the dairy industry increased annual milk production by ten million tons with 7.4 million fewer cows, reducing estimated methane emissions by almost one million metric tons of carbon. Go, dairy! But also, so many more cows, back in the day: whither methane?

So to the question of the buffalo. Presumably these animals farted just as much as today's cattle. We asked the question, why did global warming not start all that much sooner? More importantly, why am I not admiring a beachfront view (because rising sea levels) here in Western Pennsylvania at this very minute? After all:

Many individuals attribute global warming to the ozone layer eroding away or the burning of fossil fuels. Many people do not realize that methane gas in our atmosphere is a huge contributor to global warming. More surprising is that about 15% of the methane produced per year is from cattle.

So what's the story, science?

First, let's take a look at an important aspect that cattle and buffalo have in common: their stomachs.

In fact, all ruminants share this multi-chambered stomach. And what, you may ask, is a "ruminant"? Ruminants are named for the fore stomach, or rumen.

[It's] any even-toed, hoofed mammal of the suborder Ruminantia, being comprised of cloven-hoofed, cud-chewing quadrupeds, and including, besides domestic cattle, bison, buffalo, deer, antelopes, giraffes, camels, and chevrotains ... Cattle, goats, and sheep produce more methane than other livestock because of the unique physiology of their digestive systems, [though] methane emissions from sheep and goats in the United States are relatively minor.

Methane, it turns out, is a natural consequence of their unique digestive process. Their stomachs use something called "enteric fermentation," to break down carbohydrates with microorganisms, known as methanogens, into simple molecules for absorption into the bloodstream. So if it's so "natural," then why haven't the cumulative ruminants through the ages--I'm looking at you now, giraffes--farted us into complete climate collapse before now?

Because it's not their fault. It's ours.

As you've probably figured out by now, there's a big difference in the lifestyles of the buffalo of yesteryear and today's cattle. There didn't used to be. Buffalo and cattle alike used to graze over huge territories, foraging from a variety of wild grasses. Since the introduction of "industrial" farms in the 1930's, increasingly, beef cattle are "finished"--the industry term for "fattened for slaughter," in cramped feedlots, being fed things Nature never designed their stomachs for. Primarily corn, but also barley, hay, soy, and other grains and legumes. This diet gives American beef the tenderness and taste we've come to expect, but it's creating the unprecedented levels of methane that contribute to global warming.