Absorbing Carbon on Marin's Rangelands
John Wick on his Nicasio ranch, site of the carbon sequestration research / photo by Eric Slomanson
Drives through West Marin are usually noted for views of the hills, ocean, farmlands, and picturesque towns. Less visible are scientific experiments that could bring West Marin even more notoriety, since that part of the County is becoming the center of efforts to see whether carbon dioxide can naturally be absorbed by ranchlands as a way to reduce its impact on climate change.
These experiments are being supported by the Marin Community Foundation under its $10 million, five-year Strategic Initiative called Reducing the Impact of Climate Change. Under this initiative, MCF is also supporting water - and energy-efficiency efforts and ways to reduce the use of cars — all aimed at helping Marin residents make a local impact on a serious global problem.
Removing C02 from the atmosphere — a process called soil carbon sequestration — could permanently reduce atmospheric levels of CO2, explains Torri Estrada, MCF's program officer for the environment. "Marin is the perfect laboratory for this research, since we have more than 170,000 acres of rangelands that are ideal for testing, and hopefully implementing, this technique."
MCF is a lead funder of the Marin Carbon Project, a collaboration among scientists, government agencies, nonprofits, and ranchers who are working together to determine how best to maximize carbon sequestration in soils and reduce greenhouse gas emissions.
Dr. Whendee Silver — co-founder and lead scientist of the Marin Carbon Project and Professor of Ecosystem Ecology in the Department of Environmental Science, Policy, and Management at the University of California, Berkeley — explains that the experiments are taking a low-tech approach to a high-tech problem.
For example, she and her colleagues are experimenting with plows that drive holes into the ground to make it easier for rain water to be absorbed without creating erosion. They are also trying various cattle grazing patterns to determine if they have an impact on the soil's ability to absorb carbon — for example, by limiting the amount of time cattle can graze, so the grass grows back more quickly.
And they are exploring the role of spreading carbon-rich compost from cow manure on ranchlands to build up soil that can absorb more carbon.
Silver explains that for carbon sequestration to make a significant impact on climate change, the carbon must be stored for at least several years, and ideally for decades or longer. Soils in general have great potential to store carbon for long time periods, she adds.
"Doing these things takes a lot of common sense," says Silver. "It's very straightforward. If these work, they're very easy to adopt on a wide scale."
Early results, she adds, are promising. "Our first run-through suggests a very positive outcome," she says. This bodes well for the goal that's been set for this approach to reducing the impact of climate change: absorbing nearly 2,000,000 tons of CO2 from the atmosphere over the next five years.
Importantly, there's a high level of excitement among West Marin's ranchers about using land management practices that increase carbon sequestration — as well as the productivity of their land.
Some of the early research is taking place on a ranch in Nicasio owned by John Wick, project director of the Marin Carbon Project, and Peggy Rathmann. They are so invested in the project that they call themselves "carbon farmers."
"They say there's no silver bullet [to reversing global warming], but there is," says Rathmann. "It's the soil. What we're doing is using nature's strong muscles to heal itself. There's no downside to carbon-rich soil. It's the ultimate wealth."
Estrada agrees with the "double benefit" of soil carbon sequestration. "It can reduce C02 in the atmosphere while enriching the quality of the soil. And if successful, this approach could be used far beyond our County's borders."
On March 4, 2010, 16 agronomists from China's Ministry of Agriculture visited the Marin Carbon Project to learn how the techniques being tested might be used in China. An article on the visit appeared in the Marin Independent Journal.