TED Talk Teaches Us to Disparage the Desert | KCET
TED Talk Teaches Us to Disparage the Desert
I've often noticed that many environmentally inclined people dislike deserts. Sometimes it's as benign as a matter of personal preference for where to spend time: there are mountain people and forest people and ocean people, and they sometimes ask us desert people what we could possibly see in our favorite arid haunts. Sometimes that disregard is stronger than just a vacation preference. Sometimes it's an actual dismissal of the land's value, as for instance saying that thousand-year-old yuccas and threatened tortoise habitat aren't worth as much as a few megawatts of solar power or a convenient spot for trash.
Allan Savory takes it further than that: He wants to eradicate deserts just because they exist.
Savory, who has been riling up land management scientists for decades with his theories about grazing management, gave a talk in February 2013 at TED Long Beach that's available on YouTube. In that talk, he claims that the world's deserts are all human-caused, that they all were once grasslands, that they can and should be converted back to grasslands by the application of very large numbers of grazing livestock, and that his plan is the only way we as a global species could combat the effects of global warming caused by desertification.
Here's the video:
That word "desertification" is a problem. Ecologists use it to describe a real threat: the conversion of thriving but vulnerable habitats to ecologically barren wastelands. Savory claims that desertification is always caused by overgrazing, but in many places other factors play as large a role: plowing, groundwater mining, habitat fragmentation, and a range of other issues.
I've criticized the use of the word "desertification" before. It causes confusion. There are thriving, diverse arid-land ecosystems called "deserts," home to some of the most staggering biodiversity and fascinating adaptations one could imagine. They're very different from the places we humans have thrashed so completely that few things will grow there. To illustrate what I mean, here's an image of desertified land from Savory's video:
Here's a shot of some actual desert:
Kinda different, huh? And yet the language of "desertification" conflates the vibrant, healthy, exuberant, biologically diverse desert landscape with the bulldozed, trampled parking lot. For some environmentally concerned people, this is basically just a clumsy bit of semantics. They check themselves when someone asks about live deserts and agree that the terminology can be a bit misleading.
But Savory seems to take the conflation completely to heart: his TED Talk is entitled "How to green the world's deserts and reverse climate change." Not "how to repair our damage to the planet." Not "how to revegetate desertified grasslands." Savory wants to "green the deserts."
In fact, Savory is explicit in his conflation of desertified land and deserts: he defines "desertification" as "a fancy word for land that is turning to desert." Desertification, says Savory, "happens only when we create too much bare ground" in an ecosystem that has a dry season.
His strategy for "greening deserts" is to graze massive herds of livestock on those deserts. This practice has been advanced under various labels over the decades: the Savory Method, Rotational Grazing, Holistic Resource Management (HRM), and these days Holistic Management. Savory claims that livestock will cause grasslands to flourish by breaking up soil crusts, fertilizing that soil, and trimming existing grass so that it will put out new growth. This, he says, mimics the ecological pressure under which those grasslands once flourished, with massive herds of ungulates moving from place to place being followed by pack predators such as lions. For thousands of years, Savory says, human herders mimicked these migration patterns by moving their flocks continually. It's only with the advent of "scientific" management that desertification has become a problem.
Savory has spent most of his life in Southern Africa, where that paleoecological description has some small validity -- and where, for that matter, the line between actual old-growth deserts and human-trashed wastelands is somewhat less distinct. His science there has been challenged rather harshly over the decades, but at least it's plausible in an African context. But Savory doesn't limit his recommendations to Africa. He's pushing them in deserts in Australia and the Americas, where the local arid landscapes did indeed have grazers, and sometimes destructive ones -- but by no means on the scale of the Serengeti's massive herds.
I've written here, for instance, about the blackbrush vegetative community that's common at upper elevations in the California deserts. Blackbrush is quite fragile: if a massive herd of grazing animals wanders through it, it gets trampled and broken. Solid covers of blackbrush can take 10,000, even 15,000 years to develop. Solid covers of blackbrush are reasonably easy to find without much searching across the American West. Which means that across the American West, it's not hard to find vegetative communities that have not been affected by massive herds of grazers for millennia.
Which is kind of a blow to Savory's theory, though in online discussions his supporters maintain that surely those of us who pay attention to old-growth desert vegetation must be missing a history of herds of bison or something similar. In discussion on the TED video thread, one Savory backer says;
Note the insistence that old-growth deserts are in fact "desert grasslands" just waiting to be revivified, as if the rest of the flora in the desert -- the saguaros and Joshua trees and agaves and millennia-old cresosote -- were a temporary and useless encumbrance on a landscape that should be a productive meadow. Note also the insistence that if the evidence argues against Savory's methods in the American desert, that evidence must be flawed. (If there's a better field mark of pseudoscience I don't know what it is.)
Savory's talk is full of red flags, and to document and rebut each one would take more time than is really wise to spend on the talk. But three stand out as especially egregious.
The notion that bare, unvegetated soil in the American desert is an evil to be avoided flies in the face of everything we know about desert soil science. Bare soil in the desert includes desert pavement, a self-regulating system that controls air pollution. It includes alkaline crusts and dry lake beds, both homes to unique assemblages of organisms. Seemingly bare soil may hold seed banks of diverse assemblages of annual plants, some of which are limited enough in extent that covering the soil with grassland -- even if you could do so -- would push them toward extinction. And sparsely vegetated soil is crucial for the survival of many animal species, including desert tortoises, fringe-toed and horned lizards, and other animals that actually belong in the desert far more than do cattle.
The idea that grasses must be eaten by livestock to perform a valuable ecological function is similarly absurd. Grasses provide food, shelter, and even construction material for hundreds of desert animals ranging from jackrabbits to tiny insects, each of which is eaten in turn by other animals. Send in a wave of cattle to crop those grasses and we've diverted that ecological productivity to our own ends, depriving the local wildlife of food and habitat. Bunchgrasses can live for centuries if untrampled, providing year after year of ecological benefit to hundreds of generations of wildlife. Savory, like many grazing advocates, seems to regard such ancient bunchgrasses as decadent: In Lynn Jacobs' 1991 book "Waste of The West," Jacobs says "Savory claims like most ranchers that old growth range plants are 'useless' and 'decadent.'" But, adds Jacobs, "like tree snags in forests, standing dead range plant material is itself an important, natural environmental component."
Lastly, Savory's contention that the "algal crust" he shows developing on arid land soil is "the cancer of desertification" is unscientific in the extreme. He makes the statement at 4:00 into the TED video, but it's one he's made for years. Lynn Jacobs wrote in 1991 that students of (what was then being called) HRM learned from Savory that
This is, of course, completely false. Cryptobiotic soil crusts are a crucial underpinning of old-growth desert habitats across North America, and indeed throughout much of the world.
Savory has been around for a very long time preaching the same fallacious grazing gospel, and his name raises curled lips among land management scientists the way Velikovsky's name raises the ire of astronomers. He's merely the latest practitioner of a tradition a couple centuries long of land management mythologies based on wishful thinking that don't turn out to work. A century ago land speculation boosters in the American West claimed that "rain follows the plow"; Savory has merely updated that to "grass follows the cow."
But with this TED talk Savory's gone viral. His video has had more than a half a million views already, and is being lauded in terms so over the top that it's really rather embarrassing for the people doing the lauding.
It's not surprising. Most people don't know anything about the desert, and the notion of "greening" it has deep emotional resonance. To have an admittedly charismatic, soft-spoken man get up and tell us all that we can fix climate change by "greening" that desert, and that we can all have more hamburgers to boot? That's understandably tempting, even when Savory says -- at just shy of 12 minutes into his video -- that there is no other option to save the planet than instituting his grazing reforms.
The people who organize TED, though, ought to hold themselves to a higher standard. They actually have access to people who know things, the biologists and soil scientists and desert ecologists who can dismantle Savory's arguments in about 15 words. Savory spreads pseudoscientific hatred for a vulnerable ecosystem, and tells kind-hearted people that the fate of their children depends on destroying that ecosystem. Those people can be forgiven for taking him at his word. But TED has a greater responsibility to its viewers. TED should have known better.