Anthropogenic global warming?

[alextemplet]

http://www.epa.gov/methane/sources.html

Cattle farming is definitely one of the biggest sources.

What surprises me is that petroleum is a much lower source than natural gas; I always thought natural gas was supposed to be environmentally friendly.

[mith]

Supposedly better than beef

And think of it this way natural gas is methane, while petroleum probably does not generate methane in its burning instead making NO2 and sulfur compounds. So you're probably still right in that gas is cleaner burning.

[canalon]

Hm, kangaroo is one of the few animals that I haven't eaten yet. I wonder how they taste.

Lean meat. The meat is rather "fibrous" like some pieces of beef that I would not be able to name in english (it would be the diaphragm anatomically, and the "hampe" in French). I was not particularly impressed by the taste. But the price tag was impressive. Bu it was in France, this might be a reason, considering that kangaroos are not exactly endemic to the region...

[AstusAleator]

I work with the US Dept of the Interior - specifically managing federal grazing land. I can attest that grazing (historically more sheep than cattle, but now almost all cattle) has a very immediate and severe impact on ecosystems.

The additional potential harm to global climate, posed by their methane production, is really just insult to injury.

[alextemplet]

Are sheep any better for the environment than cattle?

[AstusAleator]

Not necessarily. Scientists have a hard enough time pinning down exactly what all the impacts of cattle grazing are (and furthermore extrapolating them into "good" or "bad").

Sheep grazing in the U.S. saw it's heyday in the late 1800s and early 1900s. You may have heard about "range wars" during those times. Often those "wars" were fought between cattle ranchers and sheep ranchers. Ultimately the cattle ranchers won out.

Well it wasn't until just a few decades ago that ecological impacts were really much of a factor in our land management decisions. So we don't have much scientific data from the days of widespread sheep grazing to compare to our contemporary data on cattle grazing.

Historic sheep grazing has been blamed for the disruption of ecosystems across the western U.S. It could be argued, though, that the destruction had more to do with poor management than the destructive nature of the animal. For example in 1880, 4 million sheep were recorded just in the state of New Mexico. Compare that to 2005, where the total count for the states of Colorado, Montana, South Dakota, Utah, and Wyoming was 2.65 million.

Sheep graze in a different manner than cattle. For example, they bite a plant off lower to the ground, and they prefer some different species of plants (depending on local ecology). Furthermore, they don't disturb the ground as much, due to their smaller mass. If in one area long enough, or faced with limited forage, they will eat nearly every green thing in sight - which is exactly what occured in the historic herds of thousands across the western us. They would leave a devastated wasteland in their wake, as the shepherds moved them along.

The biggest problem with sheep grazing, in my humble opinion, is the sheer number of animals. Sheep farmers enounter problems of economy of scale when considering grazing on public rangelands.

---------------------------------------

If you're interested in viewing some of my sources or reading into the topic more:

Fleischner, Thomas L. "Ecological Costs of Livestock Grazing in Western North America" Conservation Biology, Vol. 8, No. 3. (Sep., 1994), pp. 629-644.
Stable URL: http://links.jstor.org/sici?sici=0888-8 ... 0.CO%3B2-N

Denevan, William M. "Livestock Numbers in Nineteenth-Century New Mexico, and the Problem of Gullying in the Southwest" Annals of the Association of American Geographers, Vol. 57, No. 4. (Dec., 1967), pp. 691-703.
Stable URL: http://links.jstor.org/sici?sici=0004-5 ... 0.CO%3B2-7

http://www.nass.usda.gov/wy/internet/ra ... rr0508.pdf

http://www.cpluhna.nau.edu/Change/grazing.htm

http://www.cebc.bangor.ac.uk/Documents/ ... razing.pdf

[mith]

Surprisingly the cruel meat of cooped up chickens is one of the least environmentally harmful of the meats.

[alextemplet]

Hm, really makes you wonder, which is better, saving the environment or not caging the chickens? I'll take the environment over the chickens any day.

Thank you, Astus, for that well-thought out explanation. *applause*

[AstusAleator]

Free range chickens aren't too harmful either, as long as the numbers are kept down. They're good for bug-control. Just watch out for the poop when you decide to walk around barefoot. It's NASTY stuff.
Free range eggs are better for you too, though the meat's not quite as tasty and soft.

[alextemplet]

Yes I've eaten cage-free eggs before and they're delicious.

[Jones]

I live in a small community in Wyoming and all around here there are Cattle farms and ranches, and some of your information is a little off. Sheep do over graze sometimes, but it is not as often or has as big of an impact as you think. Cattle over graze is much worse, and causes major drought, so they don't let it happen, with as little water there is anyway that would be stupid. I don't think you understand the control that there is over the grazing of livestock, also the population of Sheep and Cattle are kept at a steady number because over population causes disease ESPECIALLY in Cows.

[alextemplet]

I would think that since sheep are so much less numerous than cattle, it would obviously appear that they do not leave as big of an impact on the land. I think Astus meant that, all else being equal, a given number of sheep will be worse for the land than the same number of cattle.

Also, I'm sure there are strict controls on herd sizes, but that still doesn't mean that cattle ranching isn't a major contributor to global warming, which is the topic of this discussion.