‘Climate Delusion’ Or Vital Solution? Carbon Capture’s Uphill Battle

TRACY, Calif. — When Alexa Dennett’s EV glided into Heirloom Carbon Technologies’ parking lot last August, the prospects of a net-zero future looked bright. Joe Biden was still president, and his 2022 Inflation Reduction Act had turbocharged a fledgling industry for pulling carbon dioxide from ambient air, providing generous tax breaks for every metric ton of carbon sucked from the atmosphere.

On the drive to Heirloom’s new carbon capture plant in my rented electric Ford, I had passed dozens of wind turbines scattered across golden-brown hills. Electric cars, clean energy and federal investment aplenty — this felt like a society firmly on a low-carbon pathway.

Heirloom spokeswoman Dennett and her public relations colleague, Scott Coriell, were here to show me the guts of the first commercial plant in the United States to sell credits for what’s known as direct air capture (DAC) of carbon. The technology extracts carbon dioxide from the atmosphere and then puts it deep underground for permanent storage or utilizes it in applications like concrete. Heirloom’s services have been sought by companies like Microsoft, JPMorgan Chase and Shopify, who want to offset their carbon footprints.

Heirloom had recently announced a $475 million investment to build a larger facility in Louisiana and had also won $50 million — with eligibility of up to $600 million — in federal funding for a third plant, which was part of a larger endeavor called Project Cypress that would dwarf the other two in scale. Pulling carbon dioxide from the air, after years of hype and unmet optimism, seemed on the cusp of credibility.

But standing in the parking lot edged with newly planted trees, I knew the road ahead for carbon capture remained rocky. The technology under development had enemies. Influential ones. And not the ones you’d expect. A large portion of the environmentalists you might think would support the development of a carbon capture industry were deeply, and vociferously, opposed. 

A Daunting Scale

The atmospheric math is unequivocal. Carbon must be pulled from the sky to stop the Earth from warming dangerously. In its most recent assessment report, the Intergovernmental Panel on Climate Change noted that “all available studies require at least some kind of carbon dioxide removal to reach net zero.”

But even if nations slash emissions at an eye-popping rate, they will still be shoveling carbon into the atmosphere for decades to come from hard-to-abate sectors like aviation, agriculture and steel. Before the Industrial Revolution, carbon dioxide made up 280 or fewer parts per million of our planet’s atmosphere. Today’s 430 parts per million is dangerously high.

The University of Oxford-led 2024 State of Carbon Dioxide Removal report predicts that by 2050 we will need to be removing around 7 to 9 billion metric tons of CO₂ annually and permanently to avoid a dangerous rise in sea levels, catastrophic wildfires and crop failures around the world. Given the slow pace of emissions reductions to date, that amount is probably a low-ball estimate.

As an industrial task, removing this much CO₂ from the atmosphere is mind-boggling. “The oil industry extracts about 4 billion tons of fluid out of the ground every year, and it took them 150 years to build that industry,” Heirloom’s co-founder and CEO Shashank Samala told me. However, Samala added, we now have only 20 to 30 years to make this transition.

The good news is that about 2 billion tons are already being removed annually, largely due to “conventional” methods like active forest restoration, the rewetting of peatlands and the rebuilding of coastal wetlands. These conventional methods help pull CO₂ weighing the equivalent of 20,000 fully loaded aircraft carriers from the sky each year.

The bad news is that the availability of land limits how much this number can grow. There’s only so much spare land for carbon-mitigating landscape restoration given competing demands like agriculture and housing. Even worse, increasing global temperatures are reducing the effectiveness of natural carbon sinks. This puts the ball squarely in the court of approaches like DAC.

Simple Chemistry, Complex Machinery

Motors squealed intermittently as I stood alongside two dozen floor-to-ceiling towers of neatly stacked trays at the Heirloom plant. The trays look like giant baking sheets covered in a thick, white powder — Dennett later told me this was “calcium hydroxide” — about 3 inches apart. This small test facility exists mostly as a proof of concept, extracting as much as a paltry 1,000 metric tons of CO₂ per year. But Dennett told me Heirloom is confident that “dumb rocks and smart robots” will help them scale.

The dumb rock is limestone, which is mostly made up of calcite, one of the most abundant minerals on Earth. It is also relatively benign. (“It’s in your toothpaste,” Dennett said). The limestone is ground up and heated to around 1,650 degrees Fahrenheit in an electric kiln using renewable energy. Carbon dioxide released during heating is captured and compressed into a liquid destined for long-term storage. 

The powdery residue is hydrated to produce calcium hydroxide, or slaked lime, that is spread onto trays and exposed to the air. Slaked lime is hungry for CO₂ so it can return to limestone again. With a gentle breeze blowing through the open-sided warehouse, the lime gets all the CO₂ it wants without any energy input.

The smart robots are the source of the squealing noise. They whizz up and down the stacks on vertical runners. Sensors in the robots assess the percentage of slaked lime converted into limestone. Heirloom’s proprietary technology accelerates a years-long natural process to less than three days. When satisfied with the conversion, the robots extract a tray from the stack and dump the limestone for transport back to the electric kiln. The process repeats, reusing the same materials.

Heirloom envisions fleets of fast-moving robots tending to hundreds of thousands of trays. It is a modern, highly calibrated version of a process nature has performed for more than 2.5 billion years. And to make a difference, Heirloom plans to go big. 

“To not be a rounding error on climate change, you have to believe your technology has a billion-ton pathway,” Dennett told me. That’s a million times what the squealing robots manage today in Tracy.

A scale-up of this magnitude hinges on many things going right. It needs motivated engineers with ample funding. It also needs a highly motivated public willing to put their faith in a plan that sounds almost too magical to be true.

The Environmental Enemies

DAC, an engineering process first proposed in 1999 by engineer Klaus Lackner, polarized the environmental community from the start. The World Resources Institute calls it “an important part of a climate solution portfolio.” The Center for Climate and Energy Solutions insists that “engineered carbon removal solutions will be necessary … to keep the target of warming by 1.5 degrees Celsius alive.”

But Lili Fuhr, director of the Fossil Economy Program at the Center for International Environmental Law, argues that DAC is “a dangerous distraction” and a fig leaf for more fossil fuel production. Paul Rauber, a longtime former editor of the Sierra Club’s magazine, dismissed it as a “boutique technology,” adding, “it’s too late for wishful thinking.” And Zoë Schlanger with The Atlantic labels DAC dismissively as America’s latest “climate delusion.”

There are plenty of good reasons to prioritize an end to burning carbon rather than burning it and then trying to claw it back. Coal, oil and gas give off lots of energy when ignited. But the dangerous gases they release are hard to contain, despite industry promises. The Kemper Project in Mississippi, once lavishly subsidized by the Obama Administration, was designed to gasify coal and siphon off CO₂ before it reached the atmosphere. The technology proved difficult to scale. Costs tripled, and Kemper’s clean coal machinery produced electricity for only about 100 hours before being demolished in 2021.

The collapse of confidence in carbon offsets has ratcheted up skepticism. Offsets are designed to capture carbon in one place to compensate for emissions released in another. Until now, many offsets depended on the carbon absorbed by forests. But forest carbon is hard to certify, and the offset’s validity hinges entirely on the trees remaining intact. Numerous investigations have shown that timberlands set aside for offsets have later been burned or logged. 

Another black eye for DAC is that some of the biggest players in the industry are fossil fuel companies. Occidental Petroleum bought the Canadian firm Carbon Engineering in 2023 for $1.1 billion. Occidental’s subsidiary, 1PointFive, is currently putting finishing touches to what will be the world’s biggest DAC plant, named Stratos, in the Permian Basin in Texas. Not coincidentally, the basin is the source of nearly 50% of U.S. crude oil. 

Fuhr points out that oil and gas companies already capture plenty of carbon at the smokestack, only to pump it back into aging wells. The pressurized gas snakes through fissures in the rock and acts as a solvent to force out more hydrocarbons. The process, known as Enhanced Oil Recovery (EOR), is a dubious use of captured CO₂ if you are sincere about helping the climate. “It drives us away from addressing the root of the problem,” Fuhr told me.

DAC stands little chance of gaining the social license it needs to operate if sizeable portions of the environmental community oppose it. Investment is already faltering as governments and businesses pull back from their net-zero targets. DAC desperately needs a reset, but doing so requires a commodity often in short supply when it comes to climate change: trust.

Making Carbon Capture Credible

“Permanent, durable, believable.” Without these assurances, Coriell told me, as we stood beneath an imposing tower of Heirloom’s trays, the DAC industry is doomed. 

Holly Jean Buck, a sociologist in the University at Buffalo’s Department of Environment and Sustainability, agrees. Buck is the author of “Ending Fossil Fuels: Why Net Zero is Not Enough.” She spent a year in President Biden’s Office of Fossil Energy and Carbon Management creating plans for properly engaging communities on the frontlines of the energy transition. 

Buck told me the main conversation in carbon removal these days is about “trust and establishing trust infrastructure.” It is rare for an industry’s success to hinge so centrally on an ethical idea. But carbon removal exists in a strange cultural space. It responds to a slow-moving, largely invisible, global problem. It foregrounds an industry dogged by thorny questions — questions about pollution, corporate greed, global inequity and deceit. Ethical hackles go up even before a ton of carbon is siphoned into a tank.

The checklist for morally acceptable DAC will not look the same for everyone, but a picture is slowly emerging of what that might be.

The first condition for building trust is that the captured carbon must be real and not an accounting trick; it must be believable. “Our customers demand full transparency into the lifecycle emissions of the facility,” Dennett told me. The stench of fraud from the offsets of the 2010s still lingers. 

A whole sub-industry has emerged to create credible standards for monitoring, reporting and verifying (MRV) carbon removals. Anu Khan founded the Carbon Removal Standards Initiative to create consistency across policies being enacted around the globe. “We will not build the political coalition to scale carbon removal to climate-relevant volumes without broad societal trust that this is a real thing,” she told me.

The skepticism over carbon removal is understandable. Even without its checkered history, carbon credits are not like other purchasable commodities. “The buyer doesn’t ever take physical possession of the thing; they don’t ever know if it is or is not what they thought it was,” Khan told me. “The value of the product is largely reputational.” She thinks organizations firmly rooted in civil society, alongside government and industry, have a key role to play. It is early in the game, and the rules need to be set correctly by people without a vested interest.

MRV is largely a technical matter concerned with metrics and quantification. But the different players in the MRV ecosystem all know the fundamental challenge is to clear an ethical bar. Absolute Carbon, an American company founded to set benchmarks for carbon removal quality, promises “purchasing with confidence,” “mitigating the risks of greenwashing” and “leading with transparency and integrity.” The UK-based registry Isometric has developed detailed protocols for verifying carbon credits to “rebuild trust in carbon markets.” For both companies, it is ethics all the way down. 

But being believable does not only require good accounting. It requires convincing skeptics like Fuhr that DAC is not a fig leaf. About 50 million tons of CO₂ are already pulled out of smokestacks at industrial facilities each year. That is real, measurable carbon. But the Global Carbon Capture and Storage Institute reports that 70-80% of it is pumped right back into the ground for EOR.

The International Energy Agency says that EOR reduces oil’s carbon emissions by 37%, thanks to the fact that a portion of the CO₂ injected to extract the oil remains trapped in the sedimentary formations after the oil has been pushed out. That is good. But burning hydrocarbons still creates new emissions. Unless an oil company compensates for this with additional sequestration, it is still a net harm for the climate.

This is a deal-breaker for those who want to see the fossil fuel industry disappear as quickly as possible. “I think it’s really important to take note of how the industry sells the technology,” says Fuhr. They are saying, “This is going to allow us to keep drilling for decades to come.” The Science and Environmental Health Network describes EOR as “a moral failure, a climate failure, and a threat to public health and the environment.”

Many companies developing DAC facilities have adopted operating principles that swear off EOR. Many of the entities purchasing carbon credits have demanded it, knowing their own reputation for taking climate change seriously is at stake. So far, this includes the companies buying carbon credits from Occidental’s subsidiary, 1PointFive.

The Challenge of Permanent Storage

Beyond believable, the public needs reassurance that the carbon, once accurately counted, is stored somewhere it can do no harm. The storage must be permanent and durable.

One solution is to inject captured CO₂ into concrete. Concrete mixed by the Romans still stands in the Colosseum and the Pantheon. A common metric of permanence is whether carbon is sequestered for more than 1,000 years. The Colosseum checks that box.

The Canadian company CarbonCure has developed a process for putting captured carbon into concrete. They spray CO₂ under pressure into concrete slurry at the batching plant, where it mineralizes instantly into calcium carbonate. The calcium carbonate adds compressive strength to the concrete and allows a reduction in the amount of cement needed to bind the mixture together. Since cement production accounts for 4% of global emissions, the process potentially scores two carbon wins — less cement and captured CO₂ that’s turned into carbonate.

But concrete has its detractors. It is a widespread and durable material, but it is mostly laid at the Earth’s surface and rarely left intact for as long as the Colosseum. There is also some evidence that the CO₂ injected during mixing would have been absorbed anyway as the concrete dried. So, the search is on for something better.

The most satisfying answer for permanence is to put the carbon deep underground, where it can sit in sedimentary formations similar to the ones that hold oil and gas for millennia. There is an elegant poetry to the idea of injecting carbon beneath the Earth’s surface, whence it came.

A complicated licensing process exists for what are known as Class VI wells that are suitable for this kind of permanent storage. But talk of sedimentary rock holding pockets of gas raises the specter of EOR again, even if the Class VI wells have a different purpose from the wells used for extracting oil.

A potentially more persuasive version of underground storage is a new technique involving basalt. Basalt is formed by magma rising from the Earth’s mantle, which cools into distinctively shaped polygons. It is found beneath about 10% of the Earth’s landmass and most of the ocean floor. Huge basalt formations lie close to the surface in volcanic regions such as Iceland, the U.S. Pacific Northwest and the Deccan Plateau in India. 

“In broad terms, we have orders of magnitude more storage capacity than we would ever need,” Sandra Ósk Snæbjörnsdóttir, chief scientist at Carbfix in Iceland, told me. The company is the world’s first to offer commercial CO₂ sequestration in basalt. 

Carbfix has developed a technique for dissolving CO₂ in water about 1,000 feet below the surface. The pressurized liquid reacts with minerals in the basalt to create carbonate rocks. Carbfix has shown that 95% of injected CO₂ turns to rock within two years. Leakage is also highly unlikely since the dissolved CO₂ flows downwards, and the mineralization is so quick. 

To date, the company has sequestered over 100,000 tons of carbon dioxide, including all the carbon captured in Iceland by Climeworks, the world’s first commercially operating DAC company. 

I asked Snæbjörnsdóttir how far the technology still had to go. “It’s ready,” she said, “and we are working on scaling to megaton scale.” It’s an exciting frontier. Basalt in Washington State alone could store up to 18 years’ worth of the carbon dioxide that the Oxford report said will need to be pulled from the atmosphere and sequestered annually by 2050 to maintain a safe climate. 

Basalt injection may help silence the doubts about permanence inherited from earlier types of offsets that relied on forests. The guarantee, after all, is rock solid. And the geological formations where you find basalt have no associations with EOR. It is like starting from a clean slate, Snæbjörnsdóttir told me with a slight smile.

Reassurance on quantification, permanence and durability all fall on the technical side of DAC’s trust challenges. If the engineering is convincing, if the MRV proves airtight, a pathway starts to emerge for the foundational trust the new industry needs.

Unfortunately, DAC is also plagued by a whole other set of doubts. The industry promises to be massive. Are people going to want all that noise and infrastructure when these new industrial-scale facilities set up shop in their neighborhood?

Community Buy-In

“We can’t have sacrifice zones,” she told me.

I was speaking to Kasja Hendrickson, then director of technology policy at Carbon180, a non-governmental organization that works on U.S. carbon removal policy. Hendrickson knows DAC must differentiate itself from the extractive industries that came before.

DAC as an industry hopes to grow rapidly. Occidental Petroleum alone plans for up to 135 plants as big as Stratos by 2035. It will take several thousand large facilities around the world to meet the carbon capture needs anticipated by the IPCC. The industrial build-out will involve thousands of drilling rigs, storage tanks, pipelines, air contactors, worker housing and a huge energy infrastructure to support it all. “We are talking massive scale,” Fuhr told me. “An industry that has a planetary effect.”

Carbon180 has a whole team devoted to making sure the DAC industry grows in a way that is environmentally just. “DAC needs to be scaled in a way that brings people along,” Hendrickson told me. Developers must show they can build local economies while avoiding the environmental burdens that have plagued mineral extraction and energy production throughout history.

This type of trust cannot be built by engineers and MRV protocols. It accumulates slowly by engaging closely with the people who see the industry take off from their own backyards.

The progressive edge of the DAC community is working hard to ensure the build-out creates a positive legacy. A key element is to sign “community benefit agreements” before breaking ground on any new facility. These are agreements designed to ensure new carbon capture plants will be good neighbors. They require partnering with communities and learning from local people how the new industry can best serve them. An energy company’s recently signed community benefit agreement with an environmental advocacy group as part of a project to build a CO₂ pipeline, included providing funding to train first responders, creating a community fund for counties along the pipeline and promising to pay for cleanup after they are gone.

Carbon180 calls this “transformative justice” or “removing forward.” One piece of this justice is helping people who honed their skills in the oil and gas industry transfer them to carbon sequestration. “It’s part of the just energy transition,” Hendrickson told me. “There must be a transition where we use that expertise.” Matching what matters to people with what matters to the planet builds a bridge between the global challenge of carbon and the local challenge of economic and social sustainability, she noted.

Hendrickson points out that the stakeholder engagement necessary for community benefit agreements makes good business sense, whatever your politics. “There is a fundamental financial payoff to engaging communities early and often, getting them bought into the process,” Hendrickson told me. A company has a business interest in building facilities that keep local people happy. 

An Industry Ready To Launch

The fans at Occidental’s Stratos plant are nearly ready to start spinning. Soon, the dry Texas air will blow over the potassium hydroxide and water solution in the plant’s contactors, pulling carbon from the sky. Once it is fully operational, potentially by late 2025, it’s expected to scrub 500,000 tons of CO₂ from the atmosphere annually. 

1PointFive, the Occidental subsidiary building the plant, is ambiguous about where this captured carbon will go. “The CO₂ is either permanently stored in underground reservoirs through secure geologic sequestration,” its description of the technology states, “or is used to make new products.” Occidental’s CEO Vicki Hollub is hardly reassuring about rapidly ending carbon emissions. “We believe that our direct capture technology is going to be the technology that helps to preserve our industry over time,” Hollub said at a 2023 conference for oil executives.

David Keith, a professor of geophysical sciences who designed the technology bought by Occidental, thinks that despite environmentalists’ skepticism, there is reason to welcome the oil and gas industry’s entry into DAC. It is evidence that climate concerns are being taken more seriously by the industry, and it could also be helpful to political progress on climate change overall.

“Legacy oil wants low carbon prices and high energy prices,” Keith wrote in a 2023 article for The Economist. “Carbon removal wants the opposite.” The more big players pushing on the right side of the ledger, the better.

“To be clear, we should never cut them any slack on the bad stuff they are doing,” Keith told me. “But don’t block the good stuff they are doing just because they are also doing bad stuff.”

Environmentalists are right to be on alert for greenwashing, Keith said. But in the meantime, he thinks the oil and gas industry’s skillset with large industrial and chemical processes is a boon for the fledgling industry.

The Ethics Of Climate Solutions

For Hendrickson, there is a moral dimension to every climate-related question.

Rebuilding trust is a delicate process, especially in a sector that is perpetually shrouded in suspicion, Hendrickson told me. It takes time, as well as accurate math and engineering. It involves understanding what a community needs to welcome a new industry into its neighborhood. Both types of trust are essential for building the political will needed to tackle the climate problem.

As long as DAC remains market-driven rather than sponsored by governments and treated as a valuable public service, numerous potential pitfalls could prevent the building of what Buck calls the infrastructure of trust. “History,” Buck told me, “is full of people who have values that ran up against the demands and structures of capitalism and were forced to make compromises or step away from their values because of how the system operates.”

She suspects DAC may prove to be no different.

Although still optimistic about the future of Heirloom’s rocks and robots, Dennett left the company a few months after my visit and now works for an innovation incubator. Heirloom continues to raise money and is moving ahead with its two plants in Louisiana, including the one that is part of the federally funded DAC Hub.

According to the World Meteorological Organization, as of this past January, the last decade was the hottest on record. The need to remove carbon from the atmosphere is only becoming clearer. There is little evidence that reducing emissions is going to become a priority for every country in the world anytime soon. This means that carbon removal is fast becoming an atmospheric necessity. After years in development, the technology may finally be growing viable on the scale necessary to make a difference. Its advocates are still waiting for environmentalists to give the nascent industry their blessing.

Travel for this essay was supported by a Frank Allen Field Reporting Grant from the Institute for Journalism & Natural Resources.