A Lawrence Livermore National Laboratory team has developed a program that it believes can guide California to carbon neutrality by 2045.

The program offers a three-pronged strategy for removing carbon dioxide from the atmosphere before sequestering 125 million metric tons of the greenhouse gas every year through storage underground.

Carbon neutrality means that, as a whole, California’s net carbon emissions would be zero. That is, the 125 million tons removed would balance 125 million tons emitted.

Cost of the program would be between $5 billion and $15 billion, or less than one percent of the state’s gross domestic product, according to a detailed report published last month. The exact final cost would depend largely on the technologies chosen.

The effort to develop the program cost $400,000 in private funding and took six months of “pedal to the metal” effort, according to Roger Aines, chief scientist for the Laboratory’s energy program.

Confidence that the CO2 can be stored safely and reliably underground comes from research that the Laboratory has carried out since the mid-1990s for the U.S. Department of Energy.

The effort to help California reach carbon neutrality was not funded by the Laboratory’s federal sponsors, Aines said. Instead, support came from the Climate Works Foundation via the Livermore Lab Foundation, a 501(c)3 non-profit established to provide external support to LLNL research programs.

Aines explained the program last week to a meeting of the Valley Study Group in Livermore.

Making California more aggressive

By chance, Aines’s talk followed by a week a related presentation at Livermore’s Bankhead Theater. The earlier speaker was Ellie Cohen, CEO of the Santa Rosa-based Climate Center, who addressed the importance of getting California to be more aggressive in addressing climate change.

Cohen’s talk was part of the Rae Dorough Speaker Series. It set forth an argument for going beyond carbon neutrality to negative emissions; that is, “sequestering a lot more (carbon) than we are putting out.”

She warned of dangerous, and approaching, “tipping points” such as the melting of so much ice in the northern Atlantic that cold water blocks the ocean current that carries warmth from the tropical Americas to Europe.

There is evidence that the current, known formally as the Atlantic Meridional Overturning Circulation, is slowing already, she said.

“11,000 scientists have warned that we are in a climate emergency and that decision-makers must promptly respond to the climate emergency and act to sustain life on the planet,” she said.

Her talk was co-sponsored by the Livermore Lab Foundation.

In her view, the key for California to do its part it forestalling climate disaster -- to “keep our finger away from the tipping point button,” as she put it – is to take strong action now, not wait for technologies that may or may not develop in future years.

California is admired around the world as a leader in climate protection, she said, but as the climate crisis has accelerated in recent years, the state has not kept pace.

The organization she leads, The Climate Center, advocates nature-based climate reduction strategies that can be brought to bear in the coming decade.

For example, she said, instead of disking over the soil on farms, maintaining land with cover crops allows roots to grow deep and spread, storing carbon underground. Planting perennials whose roots get longer year after year would similarly store carbon in the soil.

Even an activity as simple as applying compost to the soil preserves its carbon retention, she said.

“If we did (these things) instead of disturbing soil, we could sequester one-fifth of all our emissions annually… We have to educate farmers and ranchers. We have the know-how, we just need the funding and support to do it.”

She warned of unmeasured carbon emissions embedded in our consumer economy, particularly fuel and transportation costs, because it is so easy to order goods online that come from great distances, sometimes overnight.

While working on a local carbon sequestration task force in San Anselmo, she said, she learned that such “consumption based emissions are three times more than emissions that are measured.”

Labor unions can be more powerful than the governor or the legislature in determining the success of the decarbonization effort, she said.

Even with a legislature and governor who believe in the threat posed by climate change and the need to reduce carbon emissions, success for California will still depend on coalition building, marketing and political advocacy.

Well Received

To Roger Ahearn, chief scientist of LLNL’s energy program, the carbon neutrality program the Laboratory put before the state was well received for two main reasons.

One, its goals were limited and carefully defined. It did not presume to instruct policymakers on policy. It said, “If you want 125 million tons (of carbon dioxide sequestered) this is the set of technologies to do it.”

Two, the program did not call for unrealistic sacrifices on the part of California citizens. “Our approach was, ‘Don’t ask people to shiver in the dark.’ Instead, it was, ‘Can we achieve these final goals with the lifestyle that we all have become accustomed to, and how much will that cost?’”

There are three basic thrusts, which the report calls “pillars,” to the carbon reduction effort. None of them require resources from outside California. The “overwhelming majority” of funds would be spent within the state.

First, along the line of natural solutions that Cohen spoke of at the Rae Dorough talk, the program proposes “changes to forest management to increase forest health and carbon uptake, restoration of wood lands, grasslands and wetlands, and other practices that increase the amount of carbon stored in trees and soils.”

This approach can remove about 25 million tons of carbon dioxide per year at the relatively low cost of about $11 per ton, according to the report. In addition it has “important co-benefits to air and water quality, ecosystem and oil health, resilience to a changing climate and protection of life and property through fire risk reduction.”

The main limitation of this pillar is limited availability of the lands to make use of.

The second pillar would sequester the largest amount of carbon dioxide, about 84 million metric tons per year. It would make use of waste biomass, such as agricultural residue, forest waste and municipal garbage.

This waste today “returns its carbon to the atmosphere when it decays or burns in prescribed fires or wildfires or is used to produce energy at a power plant that vents its carbon emissions.”

The most efficient of many approaches to dealing with biomass is to convert it to hydrogen and CO2, pumping the greenhouse gas underground while making use of the hydrogen as fuel, according to the report. This has “the lowest cost and aligns with the State’s goals on renewable hydrogen.”

The third pillar is the most expensive because it requires the most energy: direct air capture, meaning removing CO2 by pulling air through a chemical processor.

Direct air capture is done on a limited scale today, so it has the potential of becoming more efficient with further experience and at a larger scale.

In all cases, the CO2 will be sequestered and injected underground in wells at depths of several thousand feet, Aines said. California has large numbers of oil wells where this can be done, as well as experienced work crews to do it.

At depth and under pressure, the carbon dioxide becomes liquid and behaves much like oil, he said. It would be stored in areas where groundwater quality is poor and not fit for drinking.

The Laboratory has years of practical experience with the underground storage process, he said, and is confident that it can be done safely and reliably.

Even the most conservative estimates of storage capacity in Central Valley wells, especially around Bakersfield but also in theSacramento Basin, suggest that billions of metric tons of CO2 can be stored there – enough for decades of sequestration.