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Bea Alvarez pierced the Pauma Valley earth with the metallic bit of her cylindrical soil tester.
She’s been tracking the amount of carbon her farm retains if she adds compost and rarely tills the land. Tilling exposes carbon from dead plants to oxygen in the air, creating carbon dioxide, which is the planet’s most troublesome climate-changing gas.
“The ultimate goal is to restore the cycles of nature,” Alvarez said. “We don’t have time to have these decades-long conversations to prove it can work. It’s not rocket science. The soil is getting healthier.”
Alvarez thinks the government should value the progress she’s made offsetting carbon emissions through farming, either by allowing investors to support her work on the carbon trading marketplace or though direct investment from the government itself. But her citizen science results don’t officially count as a means of slowing down the warming of the planet yet.
San Diego County recently committed to becoming carbon-neutral by 2035, which means cutting as much emissions as the county’s economy emits. But the state may have backed the county into a regulatory corner by limiting the ways it can take credit for cutting greenhouse gases.
Right now, when counties want to encourage investment in projects that suck carbon out of the atmosphere and bury it for good, there are only a handful of project types that truly and permanently eliminate greenhouse gases from the atmosphere and count outside of what’s already regulated like replanting a forest, capturing landfill gas or even growing rice in water-flooded fields. And the county is having trouble finding enough of them.
It’s a similar struggle for the city of San Diego, which claimed it reduced emissions by 25 percent but most of that was due to requirements from the state. Local governments have to come up with their own unique ways of curbing greenhouse gases outside of what they’re already required to do and make sure the effort is scientifically sound.
To reach the county’s goals, local governments and companies will need to have projects to invest in. Maybe a new wetlands project or a big carbon scoop in the sky, called direct-air capture technology, which theoretically sucks carbon out of the atmosphere. But that doesn’t exist yet.
A group studying the problem identified only one potential project in San Diego that fits the rules in the carbon offset marketplace, where people can go to invest in green projects. That’s replanting a burned tract of forest land in the Cuyamaca Rancho State Park, said Scott Anders, director of the Energy Policy Initiatives Center, which has contracted with the county on climate work in the past.
“The market players, up until now, have not seen an opportunity in San Diego,” Anders said. “It doesn’t mean that as time goes on, the cost of carbon goes up and policies change that it won’t change.”
That’s still frustrating for local farmers. They see the commitment to net zero emissions as a business opportunity. Deep within the county’s first Climate Action Plan lies the framework for setting up a local marketplace where the government could put local projects on the carbon offset marketplace for private investors or developers to invest in to offset whatever increases in emissions they may be causing, or to sell credits to others and help cut greenhouse gases created by San Diego’s own economy.
Farmers like Alvarez and her business partner Elle Igoe are purposefully growing crops to keep as much carbon in the soil as possible, practices now called carbon farming, an en vogue term in the climate policy space.
“It seems a lot of regulatory agencies have a lot of hardline positions instead of opening their ears to have conversations with the farmers that can show progress, and put money toward the health of the soil with really good results,” Alvarez said.
The county’s climate team is looking at carbon farming as part of its effort to write a new Climate Action Plan, county spokeswoman Donna Durckel wrote in an email. But the county says there’s limited data available on how effectively these practices sequester carbon.
“If the county were able to determine an accurate method for quantifying, verifying, monitoring and reporting carbon sequestration in this sector, reductions would likely be used in the County’s (Climate Action Plan) update as a new measure to strive toward carbon neutrality,” Durckel wrote.
That’s precisely what Matt Costa does for a living. The biological oceanographer at Scripps Institution of Oceanography spends a lot of time ankle-deep in mud on San Diego’s precious few coastal wetlands. He takes core samples of that mud, dries it, sifts it and counts carbon atoms to determine how much the whole wetland sequesters.
“Wetland soils are super high in (organic) carbon … around 70 percent,” Costa said.
But wetlands and farms share a similar problem.
“There’s no verified standard for quantifying wetland restoration as carbon greenhouse emissions (reductions),” Costa said. “If that existed, then it would probably make it more attractive for the county or city to connect their wetlands with their climate action plans but unfortunately that’s not the case.”
One Scripps study showed restoring wetlands in the county could eliminate 744 tons of carbon each year, which could translate into offset credits supported by a government or developer in the marketplace. But that’s a low number compared with the demand. The University of California system, by comparison, generates up to 500,000 tons. The San Diego International Airport says it generates about 19,000 tons of carbon emissions.
“We’ve always wanted to purchase local offsets … that’s always been the goal and we’ve had trouble finding any,” said Brenden Reed, director of planning and environmental affairs at the Airport Authority.
The unincorporated parts of San Diego County – the areas that aren’t part of another city – don’t have a lot of wetlands anyway. But the county is home to tons of farms, the most small farms in any county in the United States, in fact.
Since the concept of planting trees is a verified way by carbon offset marketplaces to reduce planet-warming emissions, Hannah Gbeh, executive director of San Diego’s Farm Bureau branch, wonders why citrus or avocado trees wouldn’t count.
“(San Diego County) has tree planting goals … and we do this for a living,” Gbeh said. “How can we incentivize them to get more root stock in the ground, sequester more carbon and make a national model for this success?”
Despite its prevalence of small farms, San Diego lost over 70,000 acres of farmland over the last nine years due to high water costs and competition with real estate developers, Gbeh said. Perhaps now the two competitors can work hand in hand.
“It’s not that complicated. We are trying to bust this myth,” Gbeh said.
But replanting tree-based farms is different than replanting a regular forest. It takes a significant amount of water to keep avocados and citrus happy, a resource that does not flow so naturally through Southern California. It takes massive amounts of energy to pump San Diego’s main source – the Colorado River – to quench demands already. A lot of that energy comes from dirty sources like natural gas-fired power plants or worse.
Alvarez and Igoe believe farms can strike a balance. They say their 80-ish acre farm on Pauma Band of Indians land retains much more water after three years of carbon farming practices.
“For every 1 percent of soil organic matter we increase … we can save an acre foot of water,” Igoe said.
And the organic carbon content of the soil is growing richer and deeper as well. Alvarez said her soil tests showed that organic carbon is seeping deeper into the soil. At first, just the first six inches were richer. After the third year, Alvarez said now the top 17 inches of soil is spongy and carbon-rich.
The two have a grant from a restaurant collaborative called Zero Food Print to do this work because soil testing is costly and most farmers operate on a razor-thin profit margin anyway. It’s hard enough just to stay in business despite all the other methods and testing they’re trying out, Igoe said.
“We’re trying to do both but the data we collect isn’t scientifically validated,” she said.
Alvarez and Igoe are part of San Diego’s Carbon Farming Task Force, which is trying to bend the ear of the county’s Board of Supervisors during the climate action planning process. Whether it shakes out as a valid way for the county to help meet its greenhouse gas reduction goals remains to be seen.
“We need healthy food. We need jobs with dignity and we need people to treat the land with respect. Carbon farming is a solution,” Igoe said.