Low-carbohydrate diet and climate change
I think you’ll agree with me when I say that the forces arrayed against us meat eating, low-carbohydrate diet followers firmly believe the ‘fact’ that running herds of animals destroys the grasslands and ecosystem. And that’s not to mention that the methane from their belches destroys the ozone layer and worsens climate change. But is it true? Are we making a Faustian bargain, those of us who enjoy the health and taste benefits of a juicy chop or sizzling steak? Are we sacrificing the planet to indulge in our own hedonistic low-carbohydrate fancies?
As it turns out, large herbivores, the very kind we like to eat, if managed properly, not only will not destroy life as we know it, but will actually reduce atmospheric carbon dioxide, sequester carbon in the soil, and reduce desertification. At the same time, large herds of densely packed ruminants, again if managed properly, will produce increased meat per acre and increased profits to the farmers and ranchers.
A win win if there ever was one.
In today’s post, I’m going to introduce you to my all-time favorite TED talk, a presentation that in broad brush strokes explains this seeming paradox of more animals equals better grasslands equals better climate.
I would have done this much sooner save for a couple of things. First, since I had yammered about it so much and practically horse whipped all my friends and family into watching it, I assumed every one had probably already seen it. Second, as I’ve mentioned before, I’m a late adopter to anything new because I’ve seen the kind of damage action without investigation can cause. So, I held off until I was able to get some scientific feedback before I ran out and gushed about all this to the world at large. Now that I’ve had the chance to look into it more thoroughly, I’m ready to pass these ideas along.
Here is the TED talk. It’s by Alan Savory on the management of large herds of herbivores to prevent desertification. If you haven’t seen it, prepare to be amazed. If you have seen it, either watch it again (I’ve watched it probably 30 times), or skip on down to the discussion below.
Pretty amazing, right?
The presentation makes it seem as if all you have to do is move a lot of cattle, goats, sheep, whatever on to the land and Voila! crappy land turns into lush grasslands. Well, sort of, but not really. It’s more complex than this video makes it appear.
But also simpler.
When enormous herds of herbivores covered large swaths of land without any management (except for the carnivorous predators that kept the herd tightly bunched and moving), they made for great topsoil, rich in carbon, water, and a host of nutrients optimal for plant growth.
The Great Plains
When settlers first pushed into the great plains of middle America, they encountered herds of bison so large they went as far as the eye could see. These early homesteaders found rich, dark top soil, sometimes many feet deep, that proved ideal for farming. At the same time these farmers fenced off the range and started planting, the buffalo hunters began decimating the bison population, almost to the point of extinction. What first seemed a crop-growing paradise, ended up a few short decades later as the dust bowl.
Desertification had sent in. The bison were gone and so were most of the farmers. The plight of the bison and the tribes who had coexisted with them for centuries was captured perfectly by Vachel Lindsay, one of my favorite poets, in The Flower Fed Buffaloes, a poem written and performed as the desertification was happening.
Despite the deep rich soil in the Great Plains of the US created by the constantly roaming herds of bison, somehow the notion got started that decimation of grasslands and their conversion to desertified scrubland was a consequence of overgrazing. This thinking led to the removal of animals to help restore the grasslands; unfortunately, the removal brought about desertification even more quickly. But despite the obvious failure in outcome, no one could be made to believe that herds of herbivores would actually produce the effect they were removing these same herds to achieve. It was the same kind of thinking that said we should all cut fat and increase carbs to reduce obesity or cure diabetes. And had about the same effect.
What does cause desertification?
After the success of Alan Savory’s TED talk, he wrote a short book describing his methods in more detail. The Grazing Revolution: A Radical Plan to Save the Earth is a terrific short read, and, if you’re interested in this subject at all, it’s one you should read.
My work shows that three management practices lead to desertification. In order of importance, they are:
- Over resting soils and plants.
- Overgrazing plants.
Let’s take these in reverse order.
Burning the fields.
For centuries people have burned fields to convert weeds and scrub to ash, which was thought to both fertilize the soil and remove competition to the perennial grasses. Problem is, it doesn’t work. Burning exposes soil, releases carbon into the atmosphere, and gives rise to plants that are more fibrous, fire resistant, and less nutritious.
Since I’ve been talking about the benefit of huge herds swarming across the grassland as being beneficial, how can overgrazing be a problem? It seems like a multitude of large herbivores massed together moving over a piece of land would be the definition of overgrazing. Yet these large herds going through actually make the grasslands grow better? What gives?
Here’s the deal…
In nature carnivorous predators keep the large herbivores bunched together as they move along. There is safety in numbers for the herbivores, so they don’t stray from the herd. If they do, they become a meal. As these herbivores move through, they defile the land with urine and feces, as in defile it for the herbivores to graze. Because of the combination of the urine and the feces accumulation and the constant threat of predators, the herbivores move along at a pretty good pace. Which prevents overgrazing and fertilizes the soil as they pass by.
As Alan Savory writes:
The healthiest land I had seen was always associated with the largest herds — thousands of buffalo, elephants, and other grazing animals — accompanied by large packs of lions, wild dogs, and hyenas that kept them concentrated and needing to move off ground fouled by their own dung and urine. That movement minimized the overgrazing of plants.
On your standard farm or ranch, cattle (for instance) are kept penned in a field. They don’t just move through, they stand and graze. And graze and graze. They don’t give the plants enough time to recover from the grazing.
Over resting soils and plants.
The over resting is the most interesting part to me. It seems kind of intuitive that burning the ground and overgrazing might not do a lot of good for the turf, but over resting?
What’s the problem there?
I always thought letting the land lie fallow was good for it.
Well, turns out it isn’t. When herds of large animals move across a piece of land, they break up the soil and tramp urine, feces, and decaying organic matter into the earth. If the land “rests” for too long after the animals move through, it develops a crust that is difficult for rain to penetrate. It also prevents the growth and spread of plants. According to Savory, over resting the land is the worst thing that can be done. And that’s exactly what people have done for eons in an effort to improve the soil.
Where large herds of bunched grazing animals were replaced by scattered animals (wild or domestic), the land was suffering from partial rest — too few animals present, providing minimal vegetation and soil disturbance. In the absence of pack-hunting predators, animals scattered while grazing and trampled few or no plants, leaving the soil bare between them. In other cases, the animals overgrazed plants by lingering too long in a place, or returning to it too soon. In short, there was an imbalance — too much grazing or trampling in some areas and not enough in others. As a result, there was less forage to cover soil and feed animals. Scientists like myself, who had insisted on reducing animal numbers, had merely aggravated the problem. Fewer animals led to more ungrazed plants, which then accumulated dead, oxidizing leaves and stems that blocked sunlight from reaching new leaf buds and emerging stems at the plant base, eventually killing the plants.
But does it really work?
It all sounds good. Too good almost. But is it true?
That’s what I wondered.
I, like everyone else, have a strong tendency to the confirmation bias. When I see something like Savory’s TED video, I so desperately want to believe it, because it confirms what I already believe. Cattle are not harmful. Eating beef doesn’t destroy the planet. Etc. Etc. Etc.
As I mentioned above, when it comes to making medical recommendations, I’m definitely not an early adopter. If I have to prescribe drugs to patients, I much prefer those that are tried and true and have been around long enough to develop a safety profile. I tweeted about this just a few days ago.
I’m the same way about most things, including Savory’s ideas. I tried looking for other sources on his method, and I found both pro and con. The number of pro-Savory articles outweighed the con, but for years, so did the pro-low-fat-diet articles outweigh the low-carbohydrate ones. And we all know how that turned out. All the articles I found, though, were in the popular press. Nothing really scientific.
I did gain some measure of peace with the whole notion when a friend of mine wrote about his own experiences on his blog Roar of the Wolverine:
Savory’s way works, I know that for sure. When I first bought my farm, about ten acres had been desertified by years of orange groves. I live in Florida where the soil is mostly sugar sand and refuses to hold water. After two years of having cattle grazing and moving the herd from one field to another, that land is now one of the most lush pasture land in the county. When I had the property appraised, the county rated my field as a meadow (A difficult rating to get), but that’s how beautiful it is – and it was all done by cattle – I did nothing but move them.
What I find interesting about the Wolverine’s experience is that it jibes completely with what Savory says in his book. The best success comes when cattle are herded from one area to another, because this more closely mimics the actual life experience in which large herbivores are ‘herded’ by packs of carnivores.
Let me digress for just a second.
While we’re on the subject of the Wolverine, everyone, and I mean everyone, should read his story to learn a couple of things. First, never, ever take lightly an invasive medical procedure. If you absolutely have to have one, go to someone who does whatever it is you need done all the time. When you read the stats for procedures gone bad, it typically looks like only a small percentage of people have adverse outcomes. Read Roar of the Wolverine to find out what that small percentage of people go through. You will never be in that small percentage if you don’t undergo the procedure. So make damn sure you need it before proceeding. That’s what second opinions are for.
Second, you’ll learn how a good diet will see you through a lot of misery. And why you’ll have to fight your doctor all the way to keep your fat and protein up and carbs low.
Okay, digression over.
I came across an article in Nature, Emerging land use practices rapidly increase soil organic matter, published in 2015 showing that intensive herding practices rapidly improves soil quality and carbon content.
From the abstract:
…within a decade of management-intensive grazing practices soil C levels returned to those of native forest soils, and likely decreased fertilizer and irrigation demands. Emerging land uses, such as management-intensive grazing, may offer a rare win–win strategy combining profitable food production with rapid improvement of soil quality and short-term climate mitigation through soil C-accumulation.
Take a look at the before and after photos of a farm in Georgia:
The area shown had been used to grow cotton and peanuts for the past 50+ years and was well on its way to desertification, if not already there. After being converted to a dairy operation, it took a mere six years of intensive grazing to bring it back.
Here we report a rapid rate of soil C accumulation accompanying conversion of row crop agriculture land to intensively grazed pastures…
In our pastures, we find that peak C accumulation occurs 2–6 years after pasture establishment…
I recommend reading the article in its entirety as the link above is to the full-text version.
The authors pretty much summarize as follows:
The expansion of this emerging land use practice on previously tilled, row crop land may improve soil quality regionally and could mitigate climate change via rapid increases in soil C. Two daunting challenges facing humanity are feeding a growing population and curtailing the impacts of climate change. Alternative land use activities that reduce environmental degradation (for example, erosion, excess fertilizer and water demand) as well as provide economically viable food can provide a win–win scenario.
Our results demonstrate that pasture-based intensively grazed dairy systems may provide a near-term solution for agricultural lands that have experienced soil-C loss from previous management practices. Emerging land uses, such as management-intensive grazing, offer profitable and sustainable solutions to our needs for pairing food production with soil restoration and C sequestration.
Which is pretty much what Alan Savory’s work has shown.
I want to finish with an important point not really mentioned in the TED talk or in the Nature paper.
These conversions from desertification to lush grasslands don’t just happen by unloading a herd of grazing animals on the crappy land and saying, There. A fair amount of planning and work is required. The animals can’t be left too long, but need to be left long enough to do their jobs of fertilizing and breaking up the crust. According to Alan Savory, ranchers need to develop a management plan so that livestock can be moved according to the optimal schedule. Otherwise the operation doesn’t work.
What I find the most fascinating about all this is that although Savory describes the techniques for livestock management by rotating them from pasture to pasture on a proper schedule, he says the best outcomes occur when the animals are actually herded.
Human herding mimics the ‘herding’ done by large predators in the wild. That replicating natural herding creates the richest soil makes sense given that grasslands, large herbivores, and carnivores all co-evolved. Just as with diet, the closer we come to what the forces of natural selection designed us to eat, the better things work.
In my view, the best part of the whole intensive grazing process is that it makes more money for the farmers/ranchers than cultivating crops. And helps sequester carbon at the same time. So, if you’ve had qualms about noshing on steaks, chops, ribs, and roasts, because of what your meat-eating, low-carbohydrate ways might be doing to the environment, your mind should be eased. The more meat we eat, the more land will be converted from crops to cows (and other livestock), and since the most economically viable way to keep the meat supply flowing is by intensive grazing, the more properly grazed and herded meat you eat, the more carbon you save.