[permaculture] Carbon Ranching/Dec 10 NPR All Things Consider/Scientists Help Ranchers Wrangle Carbon Emissions by CHRISTOPHER JOYCE/
Wesley Roe and Santa Barbara Permaculture Network
lakinroe at silcom.com
Thu Dec 10 22:41:46 EST 2009
Scientists Help Ranchers Wrangle Carbon Emissions
by CHRISTOPHER JOYCE
December 10, 2009
Listen to the Story
All Things Considered NPR
As the world's climate negotiators meet in Copenhagen to discuss how
to curb global warming, some people in Marin County, Calif., may
already have a partial solution. They call it "carbon ranching."
The idea was hatched by scientists who are trying to coax carbon
dioxide out of the air and into cattle pastures. Proponents of the
idea say if it proves effective, the practice could be used around
When dee Silver is a soil scientist at the University of California,
Berkeley. If soil is the earth's skin, then Silver might be
considered its dermatologist. Silver is steering a jeep up a hill as
steep as a ski slope in Marin County to get to plots of pastureland
she is experimenting on.
"What we're interested in doing out here is figure out how much
carbon is added to the soil and how much carbon is lost," she says.
Soil and the plants that grow in it depend on carbon. Essentially,
carbon dioxide is plant food and Silver wants them to eat more.
To encourage the uptake of carbon dioxide, Silver has spread compost
over these plots of pastureland. The compost is a mix of plant
clippings and animal manure, the same kind you might put on your
garden at home.
The compost, she says, "increases plant growth, it actually also
lowers the temperature a little bit, so the soil doesn't get quite as
hot, it doesn't stimulate as much microbial activity."
Her experiment seems to be going well. The grass here is visibly
taller, which means there is more carbon in the plant, which also
means more food for cows. Ranchers like that part.
But those microbes she mentions complicate the process. Soil is full
of them, and when they eat plants, animals and bugs, they emit carbon
dioxide into the air. So Silver's composting has to work a balance
between supercharging carbon-consuming plants - without beefing up
"What we're really trying to do here is understand what makes the
microbes go and what makes the plants go," says Silver.
So far, the grass in the composted plots grows so well that it
captures 50 percent more carbon from the air than grass in the
And the soil is taking up almost all the carbon in the compost -
carbon that likely would have gone up into the atmosphere if it
hadn't been added to the pastureland. Silver is now measuring exactly
how much that is.
To do that, her team pounds plastic domes into the ground that
capture the greenhouse gases seeping up from the soil. But Silver
says just the extra grass from composting could make a big dent in
greenhouse gas emissions, especially in this part of California.
"Grasslands, because they are in these dry regions, have really,
really high root biomass, and it tends to go pretty deep, these
plants are looking for water and that's what builds that dark,
organic rich soil and that carbon-rich soil," says Silver.
Turning A Profit
Silver thinks composting could work for thirty years before the soil
is saturated with carbon. During that time, Silver says ranchers
could see a payoff of sorts for their work. "Hopefully, they'll be
able to participate in a carbon market, where we can quantify how
much carbon is being stored on the land, and we can sell that as a
carbon offset," she says.
That idea intrigues John Wick, a rancher who owns grazing land where
Silver is conducting her experiments for the Marin Carbon Project.
"Now I think about carbon in everything I'm doing, and it's
completely changed my life. This whole ecosystem down there, is
alive, I mean up until this point it was just dirt to me, something I
pushed around with my bulldozer," says Wick.
Some farmers are a little more skeptical, though. Bob Giacomini owns
a dairy farm in Marin County. Silver is trying to persuade him to try
composting to see if his pastures will grow better, as well as store
But Giacomini is worried about the costs of these experiments. "You
know all these things sound good, but you have to look at the cost of
them all and see what the payback is."
Giacomini says he's interested in finding out that answer, but not
sure how much time and money he has to invest in figuring it out for
Creating A Market
That's where a carbon market comes in. If a climate law is passed,
industries will be looking for ways to reduce their carbon
"footprint." Paying farmers to soak up carbon in their pastures could
be one way to do that.
As for the time and know-how, there's a new office in the U.S.
Department of Agriculture in Washington designed to create a market
for exchanges like that. "The potential for landowners is huge" when
it comes to carbon ranching, says Sally Collins, director of the new
USDA Office of Ecosystem Services and Markets.
Land that stores carbon would generate extra income. Actually
measuring carbon in soil and plants isn't easy, though. Collins
acknowledges that a market won't work unless the buyers and sellers
know exactly what they're getting.
"We have got to figure out how to have one set of scientifically
based, credible standards," says Collins.
These standards would measure exactly how much carbon stays in the
soil and the grass. And even what happens to it after microbes and
cows eat it. This all sounds complicated, and it is. But as
negotiators at the Copenhagen climate meeting struggle with ways to
reduce carbon dioxide in the atmosphere, storing carbon in soil and
plants may start to look like an attractive option.
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