Soil carbon sequestration — the process of converting gaseous carbon dioxide into carbon in the soil — offers a promising (and possibly necessary) route to addressing climate change because it could be a massive carbon sink. Indeed, a report by the Pew Center on Global Climate Change estimated that use of best practices to store carbon in soil, the agricultural sector could lock away the equivalent of a few percent of the U.S.'s total greenhouse gas emissions each year. Thinking beyond climate considerations, increasing carbon sequestration can improve soil health, which then leads to better water-holding capacity, improved fertility, higher water quality around farms, and much more. But plenty of questions remain unanswered. How much carbon is stored? How long does it stay there? Can we predict how much carbon would be stored in a particular piece of land? Are some management techniques more effective than others?
The Marin Carbon Project aims to answer some of these questions. The Northern California research effort is a collaboration between a number of organizations, including the University of California and the Natural Resources Conservation Service of the USDA (the full list of collaborators is at the bottom of the post). I first learned about the project in the Spring 2010 newsletter (PDF) from the Marin Agricultural Land Trust (MALT), a non-profit that protects agricultural land in Marin County, the county immediately north of San Francisco across the Golden Gate Bridge. Thanks to careful land-use planning (and a challenging topography), Marin is home to many great food producers and grazing animals like beef cattle, diary cattle, sheep and goats (a partial list of producers can be found at Marin Organic).
Although the phrase "carbon sequestration" sounds fancy and modern, the process is as old as dirt. In fact, it's part of the soil creation process: plants use photosynthesis to extract carbon dioxide from the atmosphere and convert some of the carbon into leaves, roots and other structures. As parts of the plant are attacked by insects and microorganisms or undergo chemical reactions (e.g., oxidation), some of the carbon becomes part of the soil organic matter (the Marin Carbon Project's materials state that carbon makes up about half of the soil organic matter).
A status report on the Marin Carbon Project website (PDF) explains the project in detail. To summarize, the team will be involved in basic research, verification of results, implementation of project lessons on farms and ranches, education of land managers and the public, and development of markets for carbon storage.
The status report lists three research projects that are being led by Professor Whendee L. Silver of the Department of Environmental Science, Policy, and Management at U.C. Berkeley in research fields in Marin Country and the foothills of the Sierra Nevada mountains:
Other projects are currently being reviewed by the Steering Committee. It would be interesting to see some examination of how manure decomposition occurs in grasslands as compared to the manure at a feedlot, and examination of other pasture phenomena that could help improve life cycle analysis calculations for pastured animals.
The team plans on publishing their results in peer-reviewed journals and I expect that they will also be presenting results at conferences, writing status reports and so on. If you are interested in subjects like climate change mitigation, how to rebuild soil, or raising animals on pasture, the Marin Carbon Project is something to watch out for.
* The full list of collaborators: USDA (NRCS), the University of California, the University of California Cooperative Extension, Marin Resource Conservation District, Marin County Agricultural Commissioner, Marin Organic, and Marin Agricultural Land Trust. The project is receiving funding from the Marin Community Foundation, Rathmann Family Foundation, and the Lia Foundation.
Creative Commons License. Lower photo of cattle at Marin Sun Farms by Bonnie Powell.from , subject to a