New California CCS project has injected 7% of advertised capacity
In the spring of 2005, the United Nations convened more than 100 of the world’s top scientists in the medieval town of Oviedo, Spain, to finish a report on carbon capture and storage, or CCS — the practice of stripping carbon dioxide from smokestacks and pumping it into porous rock underground. The meeting’s hosts handed out bottles of cava, Spanish sparkling wine, with tongue-in-cheek labels saying they were to be opened only by those who truly believed the technology could work. Belief was necessary: the scientists were writing the report only because Saudi Arabia and other oil-exporting countries had pressured the U.N. to produce it despite sparse evidence, according to U.N. officials and records cited in the investigation. In turn, the U.N. hoped the report would draw the oil-producing nations into its search for climate solutions. So despite objections from some nations and environmental organizations — which warned that the report would distract from the imperative to phase out fossil fuels — the U.N.’s preeminent climate science authority, the Intergovernmental Panel on Climate Change, went ahead. For the first time, it invited a large contingent of industry researchers into the process, alongside representatives of environmental groups; the storage chapter co-led by geoscientist Sally Benson, then at Lawrence Berkeley National Lab, included authors and editors from Shell, Chevron and Saudi Aramco.
The chapter’s scientists had clashed for years over what the report should say, first at a meeting in Canada, then in Norway, Australia and Brazil. The evidence was scant: three large-scale experiments were underway, but only one — a Norwegian operation that captured carbon from a natural gas field and pumped it under the bed of the North Sea — had rigorously tested permanent storage. There, the injected CO2 astonished engineers by floating 700 feet upward through a series of geologic formations before hitting a ceiling of shale that kept it underground, and the project was deemed a success. With so little to go on, the scientists warned in their first draft that any broad statement about leakage risk would be “almost meaningless.” Bert Metz, one of the highest-ranking U.N. officials at the meeting, pressed the group for the hard numbers the report lacked: precisely how many gigatons of storage capacity the planet likely had, and whether a well-designed reservoir would hold its CO2 for more than a year or a thousand years. The IPCC’s procedures stated that reports should assess the existing research on a topic based on peer-reviewed literature, and that exceptions must be reviewed and clearly cited. David Keith, a Canadian physicist, proposed a workaround: an “expert elicitation,” an anonymous survey in which the authors would record what they expected the evidence to eventually show. Some scientists resisted, worried that educated guesses would mislead the public, they told the outlets; Benson and Metz argued that informed advice was better than nothing. The group agreed to take the survey and to keep it off the record — they would “burn it afterward,” Keith recounted — and the official report made no mention of it. “It’s not the hard science that you would prefer, obviously,” Metz later told ProPublica and Drilled.
Five months later, the IPCC published the special report. The 431-page document portrayed CCS as a potential savior for the climate, one that could enable countries “to continue to include fossil fuels in their energy mix.” It said the technology could lower the cost of stabilizing global CO2 concentrations by at least 30% and, if fully supported by policy, could account for as much as 55% of the world’s efforts to limit climate change through this century. The report acknowledged that there were still gaps in research and experience with the technology, offering extensive detail deep within its pages about the challenges and uncertainties of piecing together separate but proven steps in the CCS process. Its summary declared that “there are no major technical or knowledge barriers” to storing captured CO2 underground. Benson’s group wrote that the planet offered vast storage capacity and that well-selected, well-managed sites would likely retain 99% of the carbon pumped into them for at least 1,000 years.
The conclusions have had profound, compounding consequences, the investigation found. The report has been cited in thousands of academic papers, in legislative testimony and in media coverage. Climate modelers folded CCS into their calculations; world leaders counted on “negative emissions” when they signed the Paris Climate Agreement in 2015; governments and corporations — from most of the world’s nations to the city of Omaha, Nebraska, the band Coldplay, ice cream chains, funeral homes and ExxonMobil — made net-zero pledges premised on the technology working; and policymakers gave energy companies billions of public dollars to develop “clean coal.” By 2018, when the IPCC published its special report on reaching the 1.5-degree goal, 89 of its 90 scenarios included large-scale CCS. The presumption, the investigation found, shifted the world’s discourse from how to limit carbon pollution to how to remove it from the atmosphere after the fact.
Twenty-one years after Oviedo, a staggering gap lies between expectations and operational reality. Since 1996 — when the first large-scale project began under the North Sea — just 12 large-scale geological storage projects have been constructed, and collectively they bury less CO2 than a single power plant can emit in a year, according to the outlets’ analysis of sites listed in an International Energy Agency database. Seven of the 12 have faced technical, financial or performance issues. Scaling the technology as much as U.N. analyses suggest is needed to limit warming to 2 degrees Celsius would require CO2 injection to increase by more than 400 times, more than 2,000 new geological storage sites — a new large-scale project every four days, on average, for the next 25 years — and a CCS industry the size of the entire global oil production industry built by 2050. Transporting the gas would require 68,000 miles of specialized pipeline in the U.S. alone and at least 85 custom-built tankers worldwide, of which just four exist, at an estimated cost of tens of trillions of dollars.
The investigation traces the record through the marquee projects that followed Oviedo. Days before the meeting, BP flew Benson and a handful of other scientists to Algeria to tour In Salah, the world’s second major geologic carbon storage experiment, which the report later listed among key sites that “indicate that it is feasible to store CO2” underground at significant scale. The assessment has not held up. On a 118-degree day in 2007, inspectors heard CO2 whistling through the top of an abandoned oil well nearly a mile from the nearest injection site; workers poured cement to plug it. Satellite data then showed the desert floor above the injection sites had bulged, and mapping revealed that pressurized CO2 had sent cracks a quarter of the way up through the 3,000-foot-thick mudstone that engineers had believed impermeable — a breach that could have acidified the pan-Saharan aquifer, a source of drinking water millions of people depend on. BP and its partners eventually summoned Benson and the other science advisers to London; the dangerous gas, they could now see, was moving in ways they had predicted it could not. Nonetheless, the advisers suggested that injection proceed temporarily to see whether it could safely be done under lower pressure and with careful monitoring. But the Algerians had had enough: in 2011 BP and its partners stopped injection, and in 2012 they quietly scrapped the project. Benson described In Salah as a technical failure but a triumph of detection. “It was monitored and people found a problem,” she told the outlets. “Then,” she added, they “learned from it.”
Other flagship sites hit critical obstacles. Norway’s Snøhvit, several hundred miles north of the Arctic Circle, began injecting in 2008 on the basis of an 18-year capacity calculation, only to be relocated after three years when the site absorbed far less than expected. In the U.S., a decadelong effort to build a “clean coal” power plant outfitted with CCS was abandoned in 2015 after the government had spent $378 million in taxpayer money; Benson sat on the project’s advisory board for part of that time. The same year, Shell opened Quest, a $1 billion facility in Canada connected to open-pit oil sands mines and largely paid for by the country’s taxpayers. Once the energy required for the capture process itself is counted, Quest’s capture rate has hovered around 68%, far below the at-least-90% the industry routinely promises, according to a report by the Institute for Energy Economics and Financial Analysis. The site has also caused hundreds of microearthquakes. Shell did not respond to a request for comment.
The biggest failure came in Australia. The country allowed Chevron, ExxonMobil and Shell to drill a major natural gas field there on the condition that they bury at least 80% of the CO2 that came out of the ground with it, and the project, Gorgon, was billed as the world’s largest CCS operation. Instead, clogged injection wells and underground pressure spikes have plagued it: in the operating year ending in 2025, the companies injected just a quarter of the CO2 collected there, venting the remainder and making Gorgon the largest single source of industrial carbon pollution on the continent. “Like any pioneering endeavour, it takes time to optimise a new system to ensure it performs reliably over 40-plus years of operation,” a Chevron spokesperson wrote in an emailed response. “We realise that people refer to the challenges at Gorgon in an attempt to discredit CCS, however, as we have shown, we can capture and store greenhouse gas at scale.” Shell and ExxonMobil did not respond to requests for comment.
The investigation’s most consequential finding concerns how the 2005 report’s headline numbers were produced — and when the outlets described the process to prominent climate researchers, several were disconcerted. Oliver Geden, a vice chair of the IPCC’s forthcoming climate assessment, called the expert elicitation “an inappropriate way of assessing the literature.” Roger Cooke, a lead author on a subsequent IPCC report, said authors “are not supposed to do original research. They’re supposed to just collect what’s out there,” and that “just asking a bunch of experts to give their best guess is one of the worst things you can do.” The outlets spoke with more than 100 experts on carbon capture, climate modeling and influence in academia, including a dozen people who attended the Oviedo meeting.
In a detailed written response, Benson said she did not believe the 2005 survey violated IPCC norms, said the group’s leadership was aware of it, and disputed that the approach amounted to an informed guess, writing that “there was an enormous amount of data” to draw on. She rejected the notion that industry funding influenced her research or career, saying she has worked “tirelessly for 30 years on CCS and other climate solutions,” and described CCS as one valuable tool among many needed to address climate change. Keith, whose carbon-capture company Occidental Petroleum bought for more than $1 billion, said the survey’s goal was to provide a sense of the orders of magnitude of the capacity and risks, “because that’s what’s relevant to public policy.” He said even sites with problems have not leaked large amounts of CO2 and that the report’s broad statements “have stood the test of time”; the authors’ confidence, he said, does not suggest “that a bunch of us are tools of the fossil fuel industry.” The IPCC said it was “not in a position to comment on individual recollections,” that its process was consistent with the organization’s procedures at the time, and that its role “is to assess the full range of available scientific knowledge.” It did not provide requested records detailing the scientists’ vote. Chevron, Shell and Saudi Aramco did not respond to requests for comment. Metz referred to the IPCC’s response.
The investigation places the special report within a longer industry strategy. Internal Exxon documents obtained by the outlets show that in 1988 the company determined that any climate research it supported should serve the dual purposes of protecting the value of its oil, gas and coal while preserving the company’s business options. The American Petroleum Institute wrote in internal communications that the industry’s “license to operate” depended on companies lowering climate pollution, and that CCS “enables the use of petroleum and natural gas by providing an opportunity to capture and/or offset emissions.” At a 2023 industry conference in Houston, Occidental Petroleum CEO Vicki Hollub said a form of CCS that removes carbon from the air “is going to be the technology that helps to preserve our industry over time.” Yet even as oil industry leaders pushed the world to embrace CCS, the outlets found, they remained privately skeptical. In 2007, former ExxonMobil CEO Lee Raymond told an audience of industry leaders that carbon storage might be considered “kind of the Holy Grail” but that executing it would be “a whole different animal” than enhanced oil recovery: “You can’t assume that’s going to happen. And the cost is going to be very, very significant.” A 2011 internal BP slide deck said “the pace of CCS development has been slow and the future pace remains uncertain,” and a 2018 ExxonMobil internal presentation predicted hardly any CCS would be deployed by 2050 even as it modeled soaring emissions. A 2021 ExxonMobil document described a public relations campaign aimed at persuading political and financial elites to “believe ExxonMobil is committed to helping solve climate change,” in part by showing its CCS efforts will “play an indispensable role” in a greener economy.
Benson came to CCS only after first reacting with skepticism. She has said she first heard of the technology not long after the first large-scale project began in the North Sea in 1996, when a colleague at the Department of Energy sent her a slide deck by Princeton’s Robert Socolow about the technology. “I was like, ‘I think this is nuts,’” she told the outlets. “I just couldn’t really picture it working at scale.” But, as both an idealist and a pragmatist, she was drawn to the potential for science to solve difficult environmental problems. She made a crude calculation of how much CO2 might fit beneath California and was surprised by the answer: a lot, at least in theory. It changed her mind. As she became one of CCS’s leading experts and champions, she increasingly found herself in rooms full of oil industry veterans. In 2000, she helped establish a partnership between the Department of Energy and companies including Chevron, Texaco and BP with a focused mission: make large-scale geological storage an operational reality by 2015.
Benson’s ties to industry-supported research centers run back to the early 2000s. In 2002, she was asked to sit on the advisory council of a new BP and Ford Motor Co.-funded climate research center at Princeton University. At a summit there the following year, Benson expressed concern that focusing on leaks could undermine public support for CCS, according to meeting records and the account of another person in attendance; minutes recapping her presentation said, “Need to present optimistic estimates.”
Benson is the investigation’s central example of how closely the academic CCS world has been tied to its would-be customers. ExxonMobil’s then-CEO, Lee Raymond, had put up $100 million of the company’s money, joined by $125 million from three other companies, to create Stanford University’s Global Climate and Energy Project, one of the best-funded climate research centers in America. By 2007, Benson was helping to run that industry-funded center. The sponsorship came with a string: ExxonMobil and the other sponsors held veto power over which research projects received funding, a structure students and activists protested as a replay of the tobacco industry’s research funding. Benson defended the arrangement, saying the sponsors approved every grant Stanford recommended and never exercised the veto; the outlets’ reporting did not contradict that. When Stanford University later sought a new director for its ExxonMobil-funded climate research center, it tapped her, according to the investigation. She has published more than 50 papers on geologic carbon storage since joining Stanford, many of them underwritten by ExxonMobil and other industry sources. “I don’t know anybody else,” she told the outlets, “who would eventually provide, you know, $225 million of funding” to study climate solutions. The investigation found no evidence that Benson, widely described by colleagues as scrupulous, skewed her findings to suit her industry patrons, and she has described CCS’s flaws in her publications.
But in speeches, presentations and congressional testimony, Benson has been a persistent champion of CCS, repeatedly describing it as safe and ready for large-scale deployment despite a ringside view of its setbacks, the investigation found. In a keynote at a 2018 conference in Sweden, she showed a map of CCS facilities that included the shuttered In Salah and said, “The operations have been very good at all of these projects. And they’ve gone well in terms of safety”; she also pointed to the 2005 report’s statement that an appropriately selected, well-managed reservoir would likely retain 99% of its carbon for more than 1,000 years. “This was an expression that if you find the right site, the CO2 should be permanently stored,” she said. In a written response, Benson said she continues to cite the report’s conclusions on leakage because “the methodology was sound then and remains so,” and said she is careful to qualify her characterizations and show evidence in her presentations; she did not directly address the status of the projects portrayed in her map. She points to the natural gas industry’s underground storage and to enhanced oil recovery — where American companies have injected 100 times more CO2 over the last 40 years than into dedicated storage reservoirs, with few reported leaks — as evidence the mechanics work, though the outlets note those enhanced-recovery sites are less prone to pressure buildup and can add CO2 to the atmosphere by producing still more oil. “It seems like a credible solution because you have credible people at credible institutions working on it,” said Naomi Oreskes, a historian of science at Harvard. Stanford, asked for comment, pointed to former law school dean Paul Brest, who said faculty may seek any funding they choose so long as sponsors cannot direct the work. Benson was among the scientists recognized when the IPCC won the 2007 Nobel Peace Prize, and she later served nearly two years in the Biden White House as head of the energy division of the Office of Science and Technology Policy, where she said she provided periodic scientific advice as the Inflation Reduction Act was pushed through Congress. One of the most ambitious climate policy efforts in history, the act offered a large set of incentives for CCS that the fossil fuel industry had lobbied for intensely.
The report’s legacy now shapes the most ambitious U.S. carbon burial endeavor. In 2021, as California’s air regulator formulated the state’s climate plan, it invited Benson to present on the role CCS could play. “The fraction of CO2 retained underground is likely to be very high,” she told the California Air Resources Board, again citing the 2005 report: “This study said 99% over 1,000 years.” The board set a goal of burying more than 100 million tons of CO2 a year by 2045 — more than all the carbon that has ever been geologically stored around the world combined. This spring, California Resources Corp. began injecting CO2 beneath the Central Valley, and more than 100 applications for storage sites are pending in the U.S. alone; while President Donald Trump has cut most programs addressing the climate, the investigation notes, he has expanded subsidies for CCS. Since the California project opened in May, it has injected just 7% of its advertised capacity. California Resources Corp. is seeking permits for eight more CCS projects across the state, and other oil and gas companies have proposed four more, including two that Stanford is directly involved with. The company said in a written response that it is injecting the amount planned for early operations and will increase to capacity as the project develops.
Asked whether California could truly bury more than 100 million tons of CO2 a year by 2045, Benson hesitated for the first time in the interview. “I think it’s very challenging,” she said. “That’s a lot of infrastructure, a lot of money, a lot of projects.” Asked a second time, she demurred: “Oh gosh. If we really set our mind to it. If we could wave a wand.” She continues to argue CCS is on the rise, citing 77 operating projects identified by the Global CCS Institute and what she described as a tenfold growth in CO2 injected underground since 2005. When the outlets reviewed the same data and excluded enhanced oil recovery projects, they found just eight operating large-scale carbon burial projects on that list — 10 using the group’s more recent data — and half the increase in annual injections that Benson stated. Still, she retains faith in the technology. “These are big projects, right?” she said. “The idea that everything goes exactly according to plan, especially for these first-of-a-kind projects — it’s unrealistic.”
Many experts interviewed for the investigation insisted — often in an anguished timbre — that CCS simply must work, because decades of delay have foreclosed other paths to a stable climatic future, even as the record gives reason for doubt. “It’s always some issue,” said Glen Peters, a senior researcher at the Cicero Center for International Climate Research in Oslo, who said the community has lacked a willingness to say “it’s harder than we thought.” In September, the U.N. released an urgent new report declaring that the race to avert disruptive warming has been all but lost and that “overshoot” — temperatures rising above the world’s adopted goal of 1.5 degrees Celsius — is now a certainty. Carbon capture and storage, that report said, is one of the only ways to bring the temperatures back down.