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Greener
pastures: How cows could help in the fight against climate change
Judith
D Schwartz
July 22, 2011
http://www.guardian.co.uk/environment/2011/jul/22/cows-climate-change
In reports of
rising CO2 levels, it's easy to get the impression that the carbon-and-oxygen
molecule is a kind of toxin, some alien vapor coughed up by a century-plus
of heedless industrialism now coming back to haunt us. But on closer
inspection, it seems that the problem isn't the carbon itself-it's
that there's too much in the air and not enough in the ground.
When we consider our
CO2 predicament, we tend to fault our love affair with the car and
the fruits of industry. But the greater culprit has been agriculture:
since about 1850, twice as much atmospheric CO2 has derived from
farming practices as from the burning of fossil fuels (the roles
crossed around 1970). Over the past 150 years, between 50 and 80
percent of organic carbon in the topsoil has vanished into the air,
and seven tons of carbon-banking topsoil have been lost for every
ton of grain produced.
So, how do we get that
carbon out of the air and back into the soil? Some suggest placing
calcium carbonate or charcoal (aka "biochar") directly
into agricultural soil (see "Black Is the New Green,"
Conservation, Summer 2010). But a growing number of soil and agricultural
scientists are also discussing a low-tech, counterintuitive approach
to the problem that depends on a group of unlikely heroes: cows.
The catalyst for reducing CO2 and restoring soil function and fertility,
they say, is bringing back the roving, grazing animals who used
to wander the world's grasslands. The natural processes that take
place in the digestive system and under the hooves of ruminants
might be the key to turning deserts back into grasslands and reversing
climate change. In other words, a climate-friendly future might
look less like a geo-engineered landscape and more like, well, "Home
on the Range."
Perhaps the most steadfast
advocate of this future is Allan Savory. A 76-year-old native of
Zimbabwe, Savory has the relaxed, weathered look of a lifelong outdoorsman
more attuned to the etiquette of the bush than that of the boardroom.
In the 1960s, as a young wildlife biologist in what was then called
Southern Rhodesia, he noticed that, when livestock were removed
from land set aside for future national parks, "almost immediately,
these wonderful areas suffered severe loss of both plant and animal
species." Cattle, he began to realize, could play-if properly
managed-the crucial role in grassland ecology that used to be occupied
by herds of wild herbivores. They could help prevent and even reverse
land degradation and the desertification of grasslands, combating
in the process both human poverty and the disappearance of wildlife.
Over the course of several eventful decades-during which he was
elected to the parliament, served as an opposition leader against
Rhodesia's white-minority government, and spent four years in political
exile-Savory developed a program to put these ideas into action.
Savory's singular insight
is that grasslands and herbivores evolved in lockstep with one another.
This means that to be healthy, grasses need to be grazed. Animals
eat plants and stimulate their growth; they cycle dead plants back
to the surface, which allows sunlight to reach the low-growing parts;
their waste provides fertilizer. When a predator-say, a lion-comes
into this bucolic scene, the animals bunch together and flee as
a herd, their hooves breaking up and aerating the soil. Then, on
a new patch of land, the process starts again. This way all plants
get nibbled, but none are overgrazed. And none are overrested, which
leads to accumulated dead plant material that blocks sunlight and
hinders new growth.
To Savory, the conventional
wisdom that grazing degrades the land is an oversimplification;
what matters is how livestock are applied. He readily acknowledges
that the confined animal feeding operations usually associated with
large-scale cattle ranching are problematic, and he opposes cramming
cattle into lots on industrial farms. But he contends that this
degradation by overgrazing is a matter of time rather than numbers;
he's fond of saying that one cow continually foraging in one spot
will do damage where a hundred moving from place to place will not.
Where feedlots will harm the land, he claims, herds of well-managed
grazing animals, nibbling on native grasses and roaming from spot
to spot to elude predators and seek fresh pasture-managed in a way
that mimics their behavior in the wild-will restore the land's natural
dynamics.
For years, many in the
academic and ranching establishment dismissed Savory as a gadfly,
someone outside the agricultural and scholarly mainstream who did
his research in the open air and presented his counterintuitive
conclusions in unscientific language. Undeterred, Savory continued
to refine his framework and expand his training programs, and today
his successes have become hard to ignore. Farmers, ranchers, and
other land stewards who have attended his training programs have
brought land back from the brink across Africa, Australia, New Zealand,
and the U.S. In 2010, his Zimbabwe nonprofit, the Africa Centre
for Holistic Management, received a $4.8 million grant from the
United States Agency for International Development (USAID) to expand
its work in Africa. More recently, Savory won the 2010 Buckminster
Fuller Challenge prize, a prestigious award that supports a proposal
with "significant potential to solve humanity's most pressing
problems."
The centerpiece of Savory's
work is the 2,630-hectare Dimbangombe Ranch in northwestern Zimbabwe
near Victoria Falls, home to his Africa Centre for Holistic Management.
In the hot, dry, depleted landscape of this region, "the rains
are not what they used to be" is a frequent refrain. But Dimbangombe
looks as though it's been uniquely favored by the rain gods. It
has lush, varied grasses, flowing rivers and streams, and thriving
livestock—some four times the number of neighboring ranches.
Thanks to the renewed flow of the Dimbangombe River, elephant herds
no longer have to travel to pools but can water on the river. Women
who used to walk as much as five kilometers daily for water now
have it available in their communities. Dimbangombe has become productive
and vibrant while its neighbors, and similar environments around
the globe, are turning to desert. How? "Two things: we brought
in increased cattle numbers with holistic planned grazing, and [we]
minimized the fires," says Savory.
The Dimbangombe experiment
began in 1992, when Savory donated land he had purchased in the
1970s to develop the ranch as a nonprofit demonstration site. (A
larger parcel of land owned by Savory is now the Kazuma Pan National
Park, part of the five-nation Transfrontier Conservation Area.)
In the early days, when funds were tight, he generally camped on
the land. Even now, Savory and his wife, Jody Butterfield, director
of development at the Centre, live in a mud-and-thatch hut on the
riverbank. Savory says this is "not a hardship, as I have lived
much of my life like this and simply enjoy living amongst Africa's
big game and wildlife more than in a house."
As the ranch grew, Savory
and his colleagues ran cattle on the land, beginning with what they
could afford. "We also invited farmers in the neighboring community
who had run out of feed to add their cattle to the herd," Butterfield
says. "They needed to keep their animals alive, and we needed
numbers to restore the land. Sometimes we had 600 cattle, sometimes
300. We kept them constantly on the move."
The other key intervention,
creating firebreaks, put a stop to uncontrolled clearing fires and
to fires set by animal poachers, who sometimes torch the grass to
obliterate their tracks. These woodland and grassland fires, Butterfield
says, can go on for hundreds of miles. "Africa is burning to
death, many parts of it," adds Savory. "809 million hectares
of grassland are burned annually. The reason we're burning them
is that there are not enough herbivores to keep the grass alive."
What he means is that fires are used to clear decaying plant material
and promote fresh growth-functions that grazing herbivores are uniquely
equipped to do better. Savory contends that planned grassland fires
cause numerous problems, including leaving exposed soil (which oxidizes
and leads to runoff) and promoting fire-dependent plant species
over the more diverse and soil-enriching grasses that animals eat.
Another result of grassland fires is added atmospheric CO2. In one
hour, says Savory, a half-hectare fire pumps as much CO2 and other
pollutants into the air as 4,000 car trips.
With these strategies
applied in Dimbangombe, "each year things got better and better,"
Butterfield recalls. "Gradually over the years, the grass was
thickening up and the ground would close in, covered with plants.
Then we started noticing, 'oh, the wetlands are expanding along
the upper reaches of the river.' We started seeing sedges and reeds
growing many yards up from the riverbanks and could now see a huge
swath that was becoming wetland. In the past few years especially,
it's been quite dramatic."
Allan Savory, in his
laconic way, makes it all sound elementary. "All we've done
really is make the rainfall more effective." Parched and unproductive
regions throughout the world are not necessarily suffering from
less rain, he says. The problem is that the water leaves too quickly,
through runoff or evaporation from bare soil. Water needs to infiltrate
and remain in the soil, entering the stream and river system, and
leave only through plant growth or by entering aquifers. "All
of this we're doing with the livestock," says Savory. "We
keep operating on sound scientific principle, enhancing the organic
matter and porosity of the soil, and keeping water in the system."
The key to improving
water conditions lies in the carbon cycle. In Savory's words, "The
fate of carbon and water tend to follow each other." Carbon
in the soil acts as a giant sponge, keeping rain water in the ground
rather than allowing it to stream off. "Every one-percent increase
in soil carbon holds an additional 60,000 gallons of water per acre,"
says Steven Apfelbaum, founder of Applied Ecological Services, Inc.,
a landscape-restoration company based in Brodhead, Wisconsin. "This
means reduced erosion and sedimentation and downstream flooding."
Desertification-and associated
problems such as flooding, wildfires, and water shortages-can be
seen as a symptom of the carbon cycle gone awry, says Savory. In
the same way that plants need animals, as seen in the relationship
between ruminants and grasses, soil needs plants. "For soil
to form, it needs to be living, and to be living, soil needs to
be covered," says Australian scientist Christine Jones. Without
a cover of plants in various stages of growth and decomposition,
much of the carbon oxidizes and enters the atmosphere as CO2.
So soil carbon has huge
implications for climate change. Rattan Lal, Distinguished Professor
of soil science in the School of Environment and Natural Resources
at Ohio State University, estimates that soil-carbon restoration
can potentially store about one billion tons of atmospheric carbon
per year. This means that the soil could effectively offset around
one-third of human-generated emissions annually absorbed in the
atmosphere. Building soil carbon would also enhance food production;
and, because carbon-rich soil holds significantly more water than
its dried-out counterpart, it would help to secure watersheds and
protect against flooding and drought.
"I teach my students
that the goal [in agriculture] is to produce a positive carbon budget:
the amount of carbon returned to the land should be more than the
amount that is leaving the land," says Lal, noting that soil-carbon
levels worldwide are dropping wherever extractive farming is practiced.
He says much of Africa, Asia, and parts of Central Asia have soils
which contain as little as 0.1 percent carbon, whereas the minimum
for functionality is 1.5 percent to two percent. Savory's model,
he says, offers valuable insight on how to increase soil-carbon
levels and therefore increase fertility.
Despite his evident successes,
Savory still occupies an equivocal position in the ranching and
agricultural world. His methods have stirred surprising passions
not only among farmers and ranchers who have used them with success
but also among skeptics and detractors, who have called them "hocus-pocus"
and "more religious belief than science." Savory himself
has been likened to "the Wizard of Oz"-big on fanfare,
empty of real ideas.
This may be as much about
delivery as about science. Part of the resistance stems from the
far-reaching nature of Savory's claims. Some skeptics who might
be receptive to his ideas in the realm of animal husbandry balk
at proclamations of a total "paradigm shift" with the
ambition to rethink agriculture from the ground up. Others associate
the language of his programs-"holistic management," "holistic
decision-making"-with a New Age sensibility that seems unscientific.
Then there's the inevitable resistance to new ideas, especially
ones that bypass established business and technological systems.
Apfelbaum says that most practitioners who balk at holistic management
"simply are skeptical of change from their status quo and 'the
way ranching has always been done.'"
Another factor is that
Savory's system is less a recipe than a way of understanding the
land. This means that even when his methods work, it can be hard
to know exactly what prompts success. George Wuerthner, a photographer
and author who has written extensively about western landscapes,
says, "One thing Savory's methodology does is make ranchers
pay more attention to what they're doing on the land. That may help
in and of itself, regardless of the ecological assertions, which
I don't buy."
Some ecologists are also
concerned by the impression that Savory promotes "bring in
the cows" as a one-size-fits-all panacea. These critics often
conflate planned holistic grazing, which involves continual monitoring
and adjustment, with more formulaic grazing strategies such as "short
intensive grazing" (scheduled on-off grazing cycles) and, the
latest craze, "mob grazing" (very large herds moved several
times a day). "Grasslands are tremendously diverse," says
Jason Neff, associate professor of geological sciences at the University
of Colorado at Boulder. "Some have been grazed for thousands
of years, and some not at all. You need to look at the cultural
and ecological history of a place. I work in semi-arid lands that
are sensitive to grazing. For example, the Colorado plateau-increase
grazing out there, and the land will suffer."
Savory himself does not
claim that his methods are equally applicable everywhere. They must
take the specific local ecology into account and are best suited
to what he calls "brittle environments," parts of the
world that are dry most of the year, with seasonal rainfall. These
areas are less forgiving of land management problems than are more
temperate regions: "If, say, England had the climate of Israel,
it would have desertified," he says. "The dry periods
show up the faults [in how the land is managed]." But given
that the grassland, rangeland, and savanna-where holistic management
is most successful-cover two-thirds of the world's landmass, the
potential of his ideas is still vast.
The strength of Savory's
ideas may derive from the fact that he brings an outsider's eye-even
a poet's eye-to environmental cycles. (Nature writer Gretel Ehrlich,
who has spent time with Savory in the African bush, calls him "the
best observer of wildlife I've ever met.") Seen from a holistic
perspective, the secret of Dimbangombe is no secret. It simply required
looking back to the land's prehistory-and learning a management
principle from no management at all.
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