Sustainable Beef (Again)

Gila National Forest -- illegal grazing

Worldwatch printed a letter I wrote to them (basically a shortened version of my article "Sustainable Beef?") in their March/April 2005 issue, but with a response from Brian Halweil and Danielle Nierenberg which basically defended the idea of grazing. This article is my response to theirs. Since I don’t want to get involved in copyright issues, I have paraphrased their statements -- fairly completely, so the paraphrase is actually about the same length as their response.

Here is what they said:

1. They do not agree that grazing systems have historically always been destructive.

2. Further, they do not agree that grazing systems have been far more destructive than factory farms.

3. They acknowledge cases around the world where extreme overgrazing has occurred.

4. They assert other cases where livestock became "an integral part of the grassland ecology."

5. They cite the 1999 report, Livestock and the Environment: Finding a Balance from the UN FAO, as saying that grazing "could rehabilitate and return biodiversity to exhausted or denuded land."

6. They conceded that factory farming increases output per unit area, but don’t see benefits to the environment or public health.

7. They agree that high-meat diets are unhealthy, but not that all meat-eating is necessarily unhealthy.

8. Grass-fed meat is an improvement on factory-farmed meat, health-wise.

9. For many of the poor in semi-arid or arid regions, meat production is the only realistic way of feeding themselves.

O. K., I don’t want to be too hard on these guys. WorldWatch is a great organization, and Halweil’s Eat Here was a masterpiece of erudition and good writing (plus, it was a pretty good book). But, basically, it’s hard for me to take any of their statements about grazing seriously, and here’s why.

A variety of historians, with no obvious axe to grind, have noted overgrazing throughout India, southwest Asia, the Mediterranean, the Middle East, and North America. I cited several examples in my original letter; I could cite others. V. A. Kovda remarked that during recorded history 20 million km² of land has been rendered barren by human activity (compared to 15 million km² in cultivation today). Reagan’s secretary of agriculture, John Block, said that 60% of U. S. rangelands were overgrazed. W. K. Butzer said that in 150 years the soil resources of the U. S. have been cut in half. Regardless of whether grazing has been destructive every single time it’s been tried since the beginning of time, this is a prima facie argument that, in fact, it is typically destructive. I see neither an attempt to rebut this, nor for that matter any way of doing so.

Ungrazed

 
Grazed

The problem here is how you make your comparison between two destructive systems (grazing and factory farming). If you don’t look at soil erosion, or if you make the comparison on a per-acre basis, grazing systems don’t look that bad. If you make the comparison on a per-calorie basis, though, even factory farming comes out looking good.

Some years ago, the USDA estimated that soil erosion on rangeland averaged 5.2 tons/acre/year. Now if you compare this to (say) 7 tons/acre/year on cropland, that sounds roughly comparable. But grazing animals on an acre of land probably yields only about 1/10 the "meat calories" that growing crops on that acre (and then using it as cattle feed) would do. If you assume for the sake of argument that we have an acre of land which can be used for oats (yield of 2700 MCal), oats fed to cattle (110 MCal), or grazing land for cattle (10 MCal), and the above figures for topsoil erosion, you get these results:

Oats: 5.2 pounds of topsoil eroded / MCal
Feedlot beef: 95 pounds / MCal
Grazing cattle: 1040 pounds / Mcal

Now these values are not the last word. These statistics come from A Vegetarian Sourcebook which is now over 20 years old. You wouldn’t have to raise cattle, you could raise sheep and goats; and you wouldn’t feed oats to cattle, you would feed them something else. Soil is also being formed at the rate of about 1 ton/acre/year (optimistically). Maybe grazing land for cattle yields substantially more than 10 MCal per acre -- though by increasing the "yields" on grazing land, by overstocking, that would increase soil erosion also. And of course land which was truly good enough for cropland wouldn’t be used for grazing in the first place. But after you’ve tweaked your assumptions, you’re still going to be left with something looking like the above figures. This is a prima facie argument that grazing cattle is catastrophically worse, on a per-calorie basis, even than factory farming -- even in the relatively enlightened United States, let alone in Africa and Asia where overgrazing is probably substantially worse.

We agree on this point. I think they do not realize that this is likely more the dominant reality in the history of the world.

I read this report and did not find it helpful. It seemed to be clearly slanted toward reviewing articles and data favorable to livestock agriculture. At the outset it explicitly excluded the question of shifting from animal foods to plant foods, but assumed that animal foods were going to increase, and limited itself to determining how this could best be done. That, of course, is precisely the question I was raising in my letter -- so it is perverse for Halweil and Nierenberg to cite this review as evidence relevant to my concerns at all. It also gratuitously excluded questions of animal welfare; something I can’t fault on scientific grounds, but clearly shows to me that they were intent on thumbing their nose at anyone concerned about compassion for animals. It seemed to be bent on rehabilitating pastoral nomadism, surely historically the most destructive form of agriculture which has ever been practiced on earth. (Think: North Africa. Where did Hannibal get his elephants? From the areas later destroyed by pastoral nomadism.)

It excluded, on a priori grounds -- without citing a single study -- the idea that grazing in temperate climates could pose a problem. (The argument, surely fallacious, was that wild animals graze and this grazing is the environmental equivalent of livestock agriculture.)

The 1999 report does not really grapple with the issue of soil erosion, citing few statistics on soil erosion or even summarizing soil erosion studies. In fact, the one place where they do summarize such statistics, it actually tends to refute their contention. They state that "Conversely, well managed pasture land loses 7 MT/ha/year" whereas soil formation occurs at "1 ton/ha/year." (A metric ton is about the same as a ton.) This means that even well managed pasture land is losing about seven times as much soil as is being formed! What’s going on here?

If I were writing a book on overgrazing, I would certainly check all the footnotes they cite as a starting point for the thesis that grazing isn’t all that bad. But I wouldn’t just throw around this report as if it were evidence. To the extent that it is evidence, it actually tends to refute the thesis that grazing is environmentally benign.

If factory farming increases output per unit area, then it leaves more "wild" area (per unit of food produced) for everything else. This seems fairly obvious. If it decreases soil erosion per unit of food, this is also a benefit; again, this seems pretty obvious.

The upshot of the China Study (T. Colin Campbell) is that there was no "threshold" level below which eating animal foods did not have negative effects. Like cutting back from four packs of cigarettes a day to one pack, reducing meat consumption is an improvement, but it’s not the solution. Scientific evidence indicates that diets high in fat, high in protein, and low in fiber cause most of the "diseases of civilization" which are the root cause of most of the illness in the United States and increasingly in the less developed countries as they become more developed (e. g., China and Japan). Meat contains nothing but fat and protein, and has no fiber. Could there be a connection?

Agreed, it is marginally better.

True, but this does not mean that it is sustainable or that we should continue it. It is not sustainable. Arid and semi-arid regions are precisely where the most destruction due to livestock agriculture has historically occurred, and we should be seeking humane ways of enabling these people to support themselves in other ways. Neither the poor in Africa, nor the rich in the southwestern U. S., should be engaging in this form of agriculture in the first place.

This is a difficult subject and I don’t want to be too hard on these guys. (I hope they won’t be too hard on me, in the unlikely event they read this.) For one thing, I don’t think that the way we’re growing crops for people is sustainable either. The world is overpopulated, we’re thoughtlessly burning up fossil fuels -- there are a whole lot of things which have to change, and vegetarianism by itself is not going to solve the world’s problems.

However, I think that after impartial review of all the evidence, going through the various studies, sorting out the murky historical information and so forth, it will be found that grazing systems are more destructive to the soil than factory farming. That was my point. Further, while in an ideal grazing system you might be able to reduce the soil erosion substantially, as a practical matter this isn’t going to happen. Who’s going to regulate this, the soil erosion police? I doubt it. So don’t talk to me about grazing systems that "could" restore biodiversity.

The advantage of grazing systems is in areas other than soil preservation: grazing doesn’t require irrigation, it doesn’t require pesticides and herbicides, and cows naturally thrive on grass rather than corn. (Although I have seen people irrigating pasture land in Utah, with my own eyes.) It is certainly relatively more humane to the animals (until it comes time to slaughter them, at least). But soil is basic. If we’ve got pesticides in our food, that’s bad; but if we don’t have soil, that’s fatal. In terms of soil, grazing is the enemy of everyone who thinks they have a stake in the future of the earth.