How a new law is bringing more attention to natural carbon sequestration

Driving through Yolo County, you’ll see the expected wide expanses of farmland. That’s nothing unusual for an agricultural area like this one, but Heather Nichols has an eye for one particularly interesting feature that others might miss: Hedgerows. 

These rows of California native trees and shrubs are planted strategically alongside farmland. As the executive director of the county’s resource conservation district, Nichols has gotten familiar with their history. 

“All these big fields have trees around them,” said Nichols, gesturing at them as she drives by. “That's not always the case in agriculture, right? Sometimes it's just crops and nothing else.” 

In the past, these rows have been used by farmers for a variety of reasons. They can offer habitat for animals and attract pollinators, for example. 

But while hedgerows have been around for a long time — centuries in Europe and introduced in recent decades to California — they’re now looked at through a new lens. Nichols said that they’re particularly good at sequestering carbon. All woody vegetation, trees and shrubs included, draw in and sequester carbon, even helping store that carbon in the soil around them. 

“[About] one meter down is what researchers are saying hedgerows are able to do, get it in one meter into the soil,” said Nichols. “And it's there, it’s not going back into the atmosphere.”

Nichols said it wasn’t until very recently, perhaps the last five to ten years, that hedgerows’ ability to sequester carbon could be quantified. Now, she said the science around carbon sequestration allows their effectiveness to be measured. This makes it possible for state and local agencies to factor hedgerows, and other farming techniques, into their climate plans. 

A law passed last year, supported by environmental advocates, aims to refocus the state on natural approaches to carbon sequestration like this one. It requires state agencies to set targets for natural carbon removal and emissions reductions on natural and working lands. The approaches range from restoring wetlands to greening urban areas – in short, anything that boosts the environment’s ability to store carbon. 

Baani Behniwal, the Climate Center’s natural carbon sequestration initiative manager, helped pass the law. She describes natural carbon sequestration as “harnessing the Earth’s carbon cycle,” drawing carbon into lands and waters. 

“No matter what, there will be carbon released from our natural systems,” she said. “But it's all about ensuring that we're deploying the strategies needed to be netting more carbon in the ground and in our biomass than we are releasing from our natural and working lands.”  

Advocates of the law say that California needs to focus more on these kinds of  methods of carbon sequestration, looking at the state’s climate change scoping plan as evidence. Late in 2022, California’s air resources board finalized that plan, which outlines how the state will reach its goals for reducing emissions and accomplishing carbon neutrality by 2045. Many of its measures target vehicle emissions and boosting mass transit projects throughout the state. 

But controversy surrounded the plan’s approach to carbon removal. Some environmental groups criticized its reliance on engineered methods like carbon capture and storage, advocating for more resources to be invested in natural carbon sequestration instead. 

Behniwal said she sees a place for some of these technologies in California’s future, like direct air capture, but the state’s plans rely on these methods at a scale exceeding their proven ability. 

“Right now, it's nowhere near where it needs to be to scale up in a meaningful way,” she said. “CARB’s over-reliance on the technological carbon removal strategies is a really dangerous bet to make to reach the statewide goals.”

States throughout the country have made moves toward conserving natural lands, an effort that boosts the environment’s ability to store carbon, which culminated in a conservation plan announced in 2021. The plan, called 30x30, aims to conserve 30% of U.S. lands, freshwater and ocean areas by 2030. Taryn Finnessey, managing director of the U.S. Climate Alliance, said the elevation of these goals helped boost the concept of natural carbon sequestration to a national level.

But Finnessey said California’s approach in its new law is unique. She said it’s the most comprehensive measure she has seen when it comes to different methods of natural carbon sequestration. 

“There are other states that are doing certain pieces of this, but… not where they are taking it from setting statewide targets and goals to really scaling that down to what it would mean across different agencies,” Finnessey said. 

Nichols said she hopes the law will help bring more funding to the people doing these projects, like farmers. She said she’s already seen plenty of interest among farmers in her area. Right now, Nichols said she’s working with a few of them to create and execute plans that are centered around methods that sequester carbon. 

“We just need more money to do the projects,” she said. “That’s really the limiting factor.” 

The new law gives California’s natural resources agency until January 2024 to set natural carbon sequestration targets, supporting the state’s overall goal of carbon neutrality by 2045.