Credits<\/p>\n
Christopher J. Preston is a Missoula, Montana-based philosophy professor and author of \u201cTenacious Beasts: Wildlife Recoveries that Change How We Think About Animals.\u201d<\/p>\n
TRACY, Calif. \u2014\u00a0When Alexa Dennett\u2019s EV glided into Heirloom Carbon Technologies\u2019 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<\/a> sucked from the atmosphere.<\/p>\n<\/p>\n On the drive to Heirloom\u2019s 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 \u2014 this felt like a society firmly on a low-carbon pathway.<\/p>\n Heirloom spokeswoman Dennett and her public relations colleague, Scott Coriell, were here to show me the guts of the first commercial plant<\/a> in the United States to sell credits for what\u2019s known as direct air capture<\/a> (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\u2019s services have been sought by companies like Microsoft, JPMorgan Chase and Shopify, who want to offset their carbon footprints.<\/p>\n Heirloom had recently announced a $475 million investment<\/a> to build a larger facility in Louisiana and had also won<\/a> $50 million \u2014\u00a0with eligibility of up to $600 million \u2014 in federal funding for a third plant, which was part of a larger endeavor called Project Cypress<\/a> that would dwarf the other two in scale. Pulling carbon dioxide from the air, after years<\/a> of hype and unmet optimism, seemed on the cusp of credibility.<\/p>\n 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\u2019d 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>.\u00a0<\/p>\n A Daunting Scale<\/p>\n 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<\/a>, the Intergovernmental Panel on Climate Change noted that \u201call available studies require at least some kind of carbon dioxide removal to reach net zero.\u201d<\/p>\n 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<\/a> of our planet\u2019s atmosphere. Today\u2019s 430<\/a> parts per million is dangerously high.<\/p>\n The University of Oxford-led 2024 State of Carbon Dioxide Removal report<\/a> 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<\/a> of emissions reductions to date, that amount is probably a low-ball estimate.<\/p>\n As an industrial task, removing this much CO2 from the atmosphere is mind-boggling. \u201cThe 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,\u201d Heirloom\u2019s co-founder and CEO Shashank Samala told me. However, Samala added, we now have only 20 to 30 years to make this transition.<\/p>\n The good news is that about 2 billion tons are already being removed annually, largely due to \u201cconventional\u201d 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.<\/p>\n The bad news is that the availability of land limits how much this number can grow. There\u2019s only so much spare land for carbon-mitigating landscape restoration given competing demands like agriculture and housing. Even worse, increasing global temperatures are reducing<\/a> the effectiveness of natural carbon sinks. This puts the ball squarely in the court of approaches like DAC.<\/p>\n Simple Chemistry, Complex Machinery<\/p>\n 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 \u2014 Dennett later told me this was \u201ccalcium hydroxide\u201d \u2014 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 \u201cdumb rocks and smart robots\u201d will help them scale.<\/p>\n \n \u201cA large portion of the environmentalists you might think would support the development of a carbon capture industry were deeply, and vociferously, opposed.\u201d <\/p>\n 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. (\u201cIt\u2019s in your toothpaste,\u201d 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.\u00a0<\/p>\n 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.<\/p>\n 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\u2019s 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.<\/p>\n 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.\u00a0<\/p>\n \u201cTo not be a rounding error on climate change, you have to believe your technology has a billion-ton pathway,\u201d Dennett told me. That\u2019s a million times what the squealing robots manage today in Tracy.<\/p>\n 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.<\/p>\n The Environmental Enemies<\/p>\n DAC, an engineering process first proposed in 1999<\/a> by engineer Klaus Lackner, polarized the environmental community from the start. The World Resources Institute calls it<\/a> \u201can important part of a climate solution portfolio.\u201d The Center for Climate and Energy Solutions insists<\/a> that \u201cengineered carbon removal solutions will be necessary \u2026 to keep the target of warming by 1.5 degrees Celsius alive.\u201d<\/p>\n But Lili Fuhr, director of the Fossil Economy Program at the Center for International Environmental Law, argues<\/a> that DAC is \u201ca dangerous distraction\u201d and a fig leaf for more fossil fuel production.\u00a0Paul Rauber, a longtime former editor of the Sierra Club\u2019s magazine, dismissed it as a \u201cboutique technology<\/a>,\u201d adding, \u201cit\u2019s too late for wishful thinking.\u201d And Zo\u00eb Schlanger with The Atlantic labels<\/a> DAC dismissively as America\u2019s latest \u201cclimate delusion.\u201d<\/p>\n 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<\/a> to scale. Costs tripled, and Kemper\u2019s clean coal machinery produced electricity for only about 100 hours before being demolished<\/a> in 2021.<\/p>\n 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\u2019s validity hinges entirely on the trees remaining intact. Numerous investigations<\/a> have shown that timberlands set aside for offsets have later been burned or logged<\/a>.\u00a0<\/p>\n 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\u2019s subsidiary, 1PointFive, is currently putting finishing touches to what will be the world\u2019s biggest DAC plant, named Stratos, in the Permian Basin in Texas. Not coincidentally, the basin is the source of nearly 50%<\/a> of U.S. crude oil.\u00a0<\/p>\n 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<\/a> more hydrocarbons. The process, known as Enhanced Oil Recovery (EOR), is a dubious use<\/a> of captured CO2 if you are sincere about helping the climate. \u201cIt drives us away from addressing the root of the problem,\u201d Fuhr told me.<\/p>\n \n \u201cThe collapse of confidence in carbon offsets has ratcheted up skepticism.\u201d <\/p>\n 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<\/a> 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.<\/p>\n Making Carbon Capture Credible<\/p>\n \u201cPermanent, durable, believable.\u201d Without these assurances, Coriell told me, as we stood beneath an imposing tower of Heirloom\u2019s trays, the DAC industry is doomed.\u00a0<\/p>\n Holly Jean Buck, a sociologist in the University at Buffalo\u2019s Department of Environment and Sustainability, agrees. Buck is the author of \u201cEnding Fossil Fuels: Why Net Zero is Not Enough<\/a>.\u201d She spent a year in President Biden\u2019s Office of Fossil Energy and Carbon Management creating plans for properly engaging communities on the frontlines of the energy transition.\u00a0<\/p>\n Buck told me the main conversation in carbon removal these days is about \u201ctrust and establishing trust infrastructure.\u201d It is rare for an industry\u2019s 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 \u2014 questions about pollution, corporate greed, global inequity and deceit. Ethical hackles go up even before a ton of carbon is siphoned into a tank.<\/p>\n The checklist for morally acceptable DAC will not look the same for everyone, but a picture is slowly emerging of what that might be.<\/p>\n The first condition for building trust is that the captured carbon must be real and not an accounting trick; it must be believable. \u201cOur customers demand full transparency into the lifecycle emissions of the facility,\u201d Dennett told me. The stench of fraud from the offsets of the 2010s still lingers.\u00a0<\/p>\n 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. \u201cWe will not build the political coalition to scale carbon removal to climate-relevant volumes without broad societal trust that this is a real thing,\u201d she told me.<\/p>\n The skepticism over carbon removal is understandable. Even without its checkered history, carbon credits are not like other purchasable commodities. \u201cThe buyer doesn\u2019t ever take physical possession of the thing; they don\u2019t ever know if it is or is not what they thought it was,\u201d Khan told me. \u201cThe value of the product is largely reputational.\u201d 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.<\/p>\n 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 \u201cpurchasing with confidence,\u201d \u201cmitigating the risks of greenwashing\u201d and \u201cleading with transparency and integrity.\u201d The UK-based registry Isometric has developed detailed protocols for verifying carbon credits to \u201crebuild trust in carbon markets.\u201d For both companies, it is ethics all the way down.\u00a0<\/p>\n 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<\/a> 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.<\/p>\n The International Energy Agency says that EOR reduces<\/a> oil\u2019s 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.<\/p>\n This is a deal-breaker for those who want to see the fossil fuel industry disappear as quickly as possible. \u201cI think it\u2019s really important to take note of how the industry sells the technology,\u201d says Fuhr. They are saying, \u201cThis is going to allow us to keep drilling for decades to come.\u201d The Science and Environmental Health Network describes EOR<\/a> as \u201ca moral failure, a climate failure, and a threat to public health and the environment.\u201d\n <\/p>\n \n \u201cIt is early in the game, and the rules need to be set correctly by people without a vested interest.\u201d <\/p>\n 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\u2019s subsidiary, 1PointFive.<\/p>\n The Challenge of Permanent Storage<\/p>\n 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.<\/p>\n 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.<\/p>\n 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 \u2014 less cement and captured CO2 that\u2019s turned into carbonate.<\/p>\n But concrete has its detractors. It is a widespread and durable material, but it is mostly laid at the Earth\u2019s surface and rarely left intact for as long as the Colosseum. There is also some evidence<\/a> that the CO2 injected during mixing would have been absorbed anyway as the concrete dried. So, the search is on for something better.<\/p>\n 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\u2019s surface, whence it came.<\/p>\n 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.<\/p>\n A potentially more persuasive version of underground storage is a new technique involving basalt. Basalt is formed by magma rising from the Earth\u2019s mantle, which cools into distinctively shaped polygons. It is found beneath about 10%<\/a> of the Earth\u2019s 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.\u00a0<\/p>\n \u201cIn broad terms, we have orders of magnitude more storage capacity than we would ever need,\u201d Sandra \u00d3sk Sn\u00e6bj\u00f6rnsd\u00f3ttir, chief scientist at Carbfix in Iceland, told me. The company is the world\u2019s first to offer commercial CO2 sequestration in basalt.\u00a0<\/p>\n 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<\/a>. Leakage is also highly unlikely since the dissolved CO2 flows downwards, and the mineralization is so quick.\u00a0<\/p>\n To date, the company has sequestered over 100,000 tons of carbon dioxide, including all the carbon captured in Iceland by Climeworks, the world\u2019s first commercially operating DAC company.\u00a0<\/p>\n I asked Sn\u00e6bj\u00f6rnsd\u00f3ttir how far the technology still had to go. \u201cIt\u2019s ready,\u201d she said, \u201cand we are working on scaling to megaton scale.\u201d It\u2019s an exciting frontier. Basalt in Washington State alone could store up to 18 years\u2019 worth<\/a> 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.\u00a0<\/p>\n 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, Sn\u00e6bj\u00f6rnsd\u00f3ttir told me with a slight smile.<\/p>\n Reassurance on quantification, permanence and durability all fall on the technical side of DAC\u2019s 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.<\/p>\n 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?<\/p>\n \n \u201cThere is an elegant poetry to the idea of injecting carbon beneath the Earth\u2019s surface, whence it came.\u201d <\/p>\n \u201cWe can\u2019t have sacrifice zones,\u201d she told me.<\/p>\n 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.<\/p>\n 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. \u201cWe are talking massive scale,\u201d Fuhr told me. \u201cAn industry that has a planetary effect.\u201d<\/p>\n Carbon180 has a whole team<\/a> devoted to making sure the DAC industry grows in a way that is environmentally just. \u201cDAC needs to be scaled in a way that brings people along,\u201d 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.<\/p>\n 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.<\/p>\n 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 \u201ccommunity benefit agreements<\/a>\u201d 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\u2019s recently signed community benefit agreement<\/a> with an environmental advocacy group as part of a project to build a CO2 pipeline, included<\/a> 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.<\/p>\n Carbon180 calls this \u201ctransformative justice<\/a>\u201d or \u201cremoving forward<\/a>.\u201d One piece of this justice is helping people who honed their skills in the oil and gas industry transfer them to carbon sequestration. \u201cIt\u2019s part of the just energy transition,\u201d Hendrickson told me. \u201cThere must be a transition where we use that expertise.\u201d 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.<\/p>\n Hendrickson points out that the stakeholder engagement necessary for community benefit agreements makes good business sense, whatever your politics. \u201cThere is a fundamental financial payoff to engaging communities early and often, getting them bought into the process,\u201d Hendrickson told me. A company has a business interest in building facilities that keep local people happy.\u00a0<\/p>\n An Industry Ready To Launch<\/p>\n The fans at Occidental\u2019s 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\u2019s contactors, pulling carbon from the sky. Once it is fully operational, potentially by late 2025, it\u2019s expected to scrub 500,000 tons of CO2 from the atmosphere annually.\u00a0<\/p>\n 1PointFive, the Occidental subsidiary building the plant, is ambiguous<\/a> about where this captured carbon will go. \u201cThe CO2\u00a0is either permanently stored in underground reservoirs through secure geologic sequestration,\u201d its description of the technology states<\/a>, \u201cor is used to make new products.\u201d Occidental\u2019s CEO Vicki Hollub is hardly reassuring about rapidly ending carbon emissions. \u201cWe believe that our direct capture technology is going to be the technology that helps to preserve our industry over time,\u201d Hollub said<\/a> at a 2023 conference for oil executives.<\/p>\n David Keith, a professor of geophysical sciences who designed the technology bought by Occidental, thinks that despite environmentalists\u2019 skepticism, there is reason to welcome the oil and gas industry\u2019s 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.<\/p>\n