Scientists, land managers, fire prevention officials and environmental leaders are launching a study of Marin’s biomass—the organic waste generated by forest thinning, defensible space clearing, agriculture, yard work and food scraps—in search of innovative ways to reduce carbon emissions.
The Marin Biomass Study, which received half a million dollars in funding from the California Governor’s Office of Research and Planning last month, will examine the increasing volume of organic material generated by both wildfire prevention activities and curbside collection programs in Marin, with a goal of fostering cooperative partnerships and solutions.
Biomass produces large amounts of methane emissions in landfills, which are the source of over half the Bay Area’s human-generated methane emissions. Officials from the Marin Wildfire Prevention Authority anticipate considerable growth in biomass generation in response to wildfire mitigation practices. “There are going to be thousands of acres of this kind of work done in Marin, and we’re going to generate hundreds of thousands of tons of biomass material,” said Bruce Goines, the president of the authority and a member of the study’s steering committee. “The question is what to do with this amount of material.”
Managing biomass, whose content is typically about 50 percent carbon, means managing atmospheric carbon, the primary driver behind climate change. “How you dispose of it or what you do with it has a carbon footprint associated with it,” Mr. Goines said.
Jeff Creque, the director of the Carbon Cycle Institute and also a member of the study’s steering committee, said repurposing biomass waste can reduce emissions. Some types of biomass can be converted into energy through direct means such as power generation or as an alternative source of industrial heating—similar to how coal is used but with much lower carbon emissions. Biomass can be processed into biofuel or used in animal feed, furniture making, mulching and composting.
Biomass burned slowly and at very low temperatures in a reduced-oxygen environment—a process known as pyrolysis—will turn into biochar, a charcoal-like substance that is valuable in areas with depleted soil and low water supply. Biochar shows promise as a carbon sink on agricultural lands, and creating it produces gas and oil byproducts that can be used as fuels.
Historically, most of the county’s biomass has been taken to landfills, where it slowly releases greenhouse gases into the atmosphere for years to come. “But in California that’s no longer an option,” Dr. Creque said. “Not only is it a bad idea because that organic matter generates methane, but then we’re also not taking advantage of the resources we have.”
The Marin Biomass Study is an endorsed project of MarinCAN, the initiative originally known as Drawdown Marin, which is working to eliminate greenhouse gases by 2045. A biomass study group has met weekly for two years, inspired by a set of solutions outlined by MarinCAN.
“It has complexities to it, [which is why] it’s taken us as long as it has to lay out the frameworks for the study,” said Belle Cole, chair of the steering committee and one of the study group’s founders.
The study group submitted a proposal for the Marin Biomass Study to the state’s Climate Catalyst Fund, which is designed to increase the pace and scale of private financing for climate solutions. The fund allocated money to five biomass pilot projects ranging from the Central Sierra and the North Coast to Marin. Each pilot will develop plans to address biomass logistics and productive uses for the material.
In Marin, the study’s stakeholders include the Marin Wildfire Prevention Authority and Zero Waste Marin—the two joint powers authorities that oversee the bulk of biomass flows in Marin—and their member jurisdictions, such as Marin Clean Energy and West Marin Compost. The study seeks to create a collaborative of professionals with differing backgrounds that will develop actionable solutions. The biomass collaborative would work with public agencies, private companies, nonprofits, and other partners to identify and grow a robust and sustainable system.
Many of the projects that address carbon footprint focus on emissions, but the Marin study goes a step further by assessing the life cycle of biomass and its byproducts. One example is the potential for carbon sequestration on agricultural lands and in forests. Dr. Creque said soil, including forest soil, is often ignored as a carbon sink. Moving repurposed biomass material back into local soils has many benefits for agriculture, forests and grasslands, he said.
“If we can transform this above-ground fire hazard into a below-ground beneficial material, we can achieve a number of ecosystem enhancement objectives simultaneously,” Dr. Creque said.
Marin already has data around the climate benefits of applying compost to grazed grasslands, and the study will work closely with farmers. Nancy Scolari, the executive director of the Marin Resource Conservation District, which is acting as fiscal agent for the study, says the work will also look at how biomass can be used as an economic resource. This involves asking questions such as, “Does agriculture have a need for wood chips?” “How do we connect the forestry industry to farms?”
Examining biomass waste streams in Marin, where they’re going and where they’re coming from will help the county support new biomass-to-product and biomass-to-energy facilities, avoiding the need to export that work elsewhere. For example, PG&E trucks the woody biomass it collects as part of its fire prevention work to DTE Stockton, a facility that helps the energy company meet its portfolio requirements. DTE, once a coal-fired plant, utilizes 32,000 tons of woody biomass annually, creating electricity for 45,000 homes. But trucking Marin’s debris to Stockton means a roundtrip of at least 150 miles.
Although so-called bioelectricity has been shown to have a positive carbon footprint, the current transportation process leaves a significant footprint. Mr. Goines says it’s possible that a company such as Marin Sanitary Service or Redwood Landfill would consider investing in the construction of a similar facility.
Terry Sawyer, an oyster grower and the treasurer for the Marin R.C.D., is interested in minimizing the carbon footprint of farming and believes the study will offer win-win solutions. “I think this is going in absolutely the right direction,” he said. “The spreading of compost is better to do on site than trying to truck it from one end of the county to the other, so things like biochar and the biomass aspect should really be explored.”
It’s an ambitious project, but Dr. Creque believes the study can identify best practices and recommendations for Marin. “It’s complicated. There’s no silver bullet here. But how carbon moves into and through these systems is crucial, and the biomass study is really about looking at this problem from all angles,” he said.