I spent the second half of my pilgrimage to California last month in the Bay Area, visiting an olive farm, a winery, catching up with a climate activist, and spending a day with John Wick, a landowner and founding member of the Marin Carbon Project, located near Nicasio, in Marin County. I met John two years ago, on my initial carbon pilgrimage to the Golden State, and was deeply impressed by what I learned. In response, I invited John to speak at Quivira’s Annual Conference in 2010, along with Dr. Jeff Creque, an agroecologist and fellow founding member of the Marin Carbon Project (MCP).
On this return trip, I was eager to find out how things were coming along. But I should back up a bit first.
The principle goal of the MCP is to explore the value of local soil carbon sequestration in rangelands – private ranches and publicly owned open space – to provide ecological and agricultural benefits to rural communities. Rather than get into the “weeds” here, however, I think the best way to explain the promise of the Project is to quote from a National Public Radio story, reported by Christopher Joyce, titled “Scientists Help Ranchers Wrangle Carbon Emissions.”
It ran on December 10th, 2009, just as the critically important United Nations Conference on climate was beginning in Copenhagen, Denmark. I heard the story in the kitchen of my house, while doing the dishes. The general news from Denmark was already rotten, I thought. A comprehensive agreement to reduce greenhouse gas emissions looked like an impossibility, so I pricked up my ears when the NPR story started. Joyce reported:
“…some people in Marin County, California, 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 the world.
Whendee 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.
“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 carbon-producing microbes.
Scientists are experimenting with grassy pastures like this one in California to increase how much carbon dioxide the pastureland captures from the air. 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 untouched plots. 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.
“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.
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.
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.”
As we know, negotiators in Copenhagen failed to produce anything substantive and follow-up meetings in meetings in Cancun, Mexico, and Durban, South Africa, likewise failed. John remained undaunted, however. That’s because he knew that the potential the planet’s grasslands to sequester CO2 in its soils was huge. “We can solve climate change right here on the ranch,” he told me during my first visit. “There’s no doubt about it.”
John’s revelation began in November, 2007, when he went to hear permaculture guru Darren Dougherty speak about soil carbon – the stuff that makes life thrive underground. What he heard changed John’s life. Like many people, John worries about the buildup of greenhouse gases in the atmosphere. This buildup began with the invention of agriculture nine thousand years ago, expanded with the advent of fossil fuel combustion during the Industrial Revolution, and dramatically accelerated in recent decades.
The main culprit is carbon dioxide, a colorless and odorless gas which has existed on Earth in small, but varying, quantities for billions of years. In many ways, carbon dioxide (CO2) has been given a bad rap. It is, after all, an essential gas for the maintenance of life on the planet. As every schoolchild knows, all green plants require CO2 to live. In other words, CO2 is a good gas. But like any substance, it’s only good in proper amounts. Scientists warn us that there is too much CO2 in the atmosphere, creating a potentially toxic situation for life on Earth. Levels of CO2 must come down, they insist, way down.
This is where Darren Dougherty’s talk comes in.
Dougherty reported that a mere 2% increase in the organic content of the planet’s soils, particularly in its grasslands, could soak up all the excess carbon dioxide in the atmosphere within a decade. The hairs on John’s neck stood up. Soils around the planet, Dougherty continued, have been mismanaged for centuries, resulting in the depletion of their original organic content – and thus their capacity to soak up CO2. But now, in a big irony, all these depleted soils were available to start absorbing all that troublesome atmospheric CO2 again – if we rebuilt their organic content through better land management. Our mission, Dougherty said, is to build topsoil – and save the planet.
John was stunned. Could it be true? Could it be that simple? It’s estimated that the original soil carbon content of the rich, dark prairies of the American Midwest, before the Great Plow-up began in the mid-1800s, was as high as 25%. Today, this total has fallen to around 4% in many places, thanks to plowing and erosion, all of which depleted the soils of its organic content. Doughtery’s idea to reverse this slide was highly intriguing, John thought. But soak up all the excess CO2 in the atmosphere? That was crazy talk!
Or maybe it wasn’t.
The wheels in John’s head were turning, so as soon as he returned home he began to read about the carbon cycle. This is the process by which carbon dioxide flows out of the atmosphere and into the soil via photosynthesis and green plants, as organic carbon, then back out again into the air via decomposition and respiration, round and round in a perpetual circle – sustaining nearly all life on Earth. It wasn’t a complete circle, however. A bunch of the carbon stayed in the soil, having exited the plants roots in order to feed the microbial life there, where it stayed for decades if it wasn’t disturbed.
In other words, Dougherty was right, at least in principle – excess CO2 not only could be pulled out of the air by a natural process, it could be stored safely in the soil for long periods of time. It’s called sequestration, which the dictionary defines as the process of “safekeeping, withdrawing, or seizing for the purposes of placing in custody.” What if we became carbon sheriffs, John thought, seizing excess CO2 and placing it into custody of soils for a lengthy jail term – where it would feed plants and promote life.
Now John’s wheels really began to turn. Three ideas leapt to mind after Dougherty’s talk:
- Could farming and ranching actually play a significant, positive role in reducing excess CO2?
- Could the practices that sequester CO2 in the soil also improve land health – and profits?
- Could this be the basis of a new carbon economy?
John decided to find out. And in early 2008, the Marin Carbon Project was born.
Here is a photo of John speaking to a Chinese delegation about CO2 in 2010: