I grabbed this article out of Jess' Twitter feed. Obviously, pretty serious stuff. It reminds me of a few things about the midwest. Now I'm not a farmer or even very knowledgeable about farming or its affect on the land. But I've been to Iowa and Wisconsin. Huge parts of Iowa just reek of manure all summer. And Wisconsin, as all Illinoisans know, smells like cow farts. And anyone that's been on the University of Illinois campus when a big wind kicks up from the south has caught a whiff of that same odor. Lynn Henning is from Michigan, and I can't personally recall any awful smells coming from Michigan, but I don't think I've ever been around her part of the state. I think I'll take her word for it.
Now I'm living in Wyoming. Cattle country. A midwesterner might be inclined to ask me about the smell. There are a few cattle ranches within running distance of my house, not much farther than the South Farms are from most of the UIUC campus. And I go on long runs and bike rides past herds of grazing cattle all the time. And there is, honestly, no smell. There is lots of public land where farmers are allowed to graze their cattle, and I run on some of that land often. Some days you have to dodge a cow-pie every couple steps. I bike through ranch country all the time, right up next to fences with cows lined up looking out across the road. There's certainly a much higher concentration of manure from one animal in those fields than you'd ever see naturally. But there's no nasty midwestern-style cow smell.
So that tells me that the cows in Wisconsin, the pigs in Iowa, and whatever they have down on the South Farms must be packed in a lot tighter than cattle in Wyoming. And, indeed, it turns out that modern CAFOs (Concentrated Animal Feeding Operations, a term used in the above article) have giant manure pits because the land can't possibly absorb all of it (this is graphically documented in Jonathan Saffron Foer's Eating Animals). That sometimes they just spray the manure into the air when they have no place to put it. These are massive concentrations of animals. Consider the old Chicago Stock Yards, where there was once a layer of congealed blood six feet deep at the bottom of the Chicago River. That was one square mile of extremely dense slaughtering and packing facilities -- the “hog butcher to the world”. Now Lynn Henning documents a creek running red with bloodworms. She and many others have documented the diseases running rampant in factory farms. We'll destroy the countryside as thoroughly as we destroyed Chicago. In some places we already have.
And it's completely unnecessary. I've heard that cattle and sheep herds have caused their share of problems in Wyoming, that native grass species have been wiped out by grazing and that the landscape has thus been changed forever. But we aren't creating toxic waste pools. Our creeks don't run red. It seems plausible that Wyoming agriculture could go on with relatively few changes for a long time (it might require growth and sprawl to stop eventually). So maybe, just maybe, it's possible to raise lots of animals for slaughter without completely devastating everything (land, water, air, wildlife, human health... care to think of anything more?) nearby.
But there's a trade-off: we can only do it at Wyoming density. Yes, Wyoming exports beef, but it imports plenty of other things, and we'd need lots of land to produce many of those things in a minimally-destructive way. If we wanted, as a nation, to raise and eat as many animals per-person as we do today, and also wanted to avoid the massive abuses of factory farming, I'd guess our population density would have to be closer to Wyoming's than the nation's as a whole.
The other option, of course, is to cut back severely on meat production and consumption. Animals raised for slaughter eat vastly more calories in grain over their lifetimes than they provide (were this not so we'd have some explaining to do to the Thermodynamic Police). This is even true of protein, by several times (the average meat-eating American eats way too much protein anyway). Without animal agriculture we'd need far fewer fields of corn and soybeans, which are no great friends to the environment themselves.