Climeworks’ Mammoth facility in Iceland began pulling carbon dioxide directly out of the open air in 2024, its rows of fan units drawing in ambient atmosphere and chemically stripping out CO2 before injecting it deep underground into basalt rock formations where it mineralizes into stone over a period of years.
The plant represents one of the largest operating direct air capture facilities in the world, and it can remove a volume of carbon dioxide each year that amounts to a rounding error against global annual emissions, a gap that captures both the technical achievement and the sobering scale problem still facing the entire carbon capture industry.
Visitors touring the facility often describe a similar reaction: real awe at the engineering, followed almost immediately by a sense of how much larger the effort would need to become before it registers as more than a demonstration project against the scale of the global emissions problem it is meant to address.
Direct Air Capture Plants Now Operating
Direct air capture technology pulls carbon dioxide directly from ambient atmospheric air, distinguishing it from point-source capture systems that intercept emissions at their origin, such as a power plant smokestack. Climeworks, Carbon Engineering, and Global Thermostat represent the most prominent companies operating or developing large-scale direct air capture facilities, each using slightly different chemical processes to bind and extract CO2 from the surrounding air before it can be concentrated and stored.
- Chemical binding methods: most direct air capture systems use either liquid solvents or solid sorbent materials that chemically bind to carbon dioxide molecules, later releasing concentrated CO2 through a heating process.
- Energy intensity: the extraction and regeneration process requires substantial energy input, making the facility’s own carbon footprint and energy source a critical factor in its net climate benefit.
- Iceland’s geological advantage: several major direct air capture facilities have located in Iceland specifically to access abundant geothermal energy and nearby basalt rock formations suitable for mineral storage.
- Scale limitations: even the largest currently operating facilities capture a volume measured in tens of thousands of tons annually, a small fraction of what would be needed to noticeably affect global atmospheric concentrations.
The technology works as demonstrated, chemically and physically, but the central challenge facing direct air capture has never been proving the concept works; it has been scaling it to a size relevant to the multi-billion-ton scale of global annual emissions while keeping costs manageable.
Occidental Petroleum’s Stratos facility in Texas, developed through its subsidiary 1PointFive, represents the next generation of direct air capture ambition, designed to capture a substantially larger annual volume than earlier facilities once fully operational.
The project’s backing by a major oil company has drawn its own scrutiny, with critics questioning whether an oil producer’s investment in carbon removal reflects real climate commitment or a strategic hedge that helps justify continued fossil fuel production under a broader net-zero framing.
Point-Source Capture at Industrial Smokestacks
Point-source carbon capture, which intercepts carbon dioxide at concentrated emission sources like power plants, cement factories, and steel mills, has a longer commercial track record than direct air capture and benefits from working with far more concentrated CO2 streams that require less energy to process per ton captured.
Facilities including the Petra Nova plant in Texas and Boundary Dam in Saskatchewan have demonstrated the technology’s viability at industrial scale, though both projects also illustrate the operational and financial challenges that have limited broader adoption.
- Higher concentration advantage: exhaust streams from industrial sources contain far more concentrated CO2 than ambient air, making point-source capture inherently more energy-efficient per ton captured than direct air capture.
- Retrofit complexity: adding capture equipment to existing industrial facilities requires significant engineering integration and can reduce a plant’s overall energy output, since some portion of generated power must run the capture system itself.
- Cement and steel applications: heavy industry sectors with few viable decarbonization alternatives, including cement and steel production, have drawn particular interest for point-source capture given the difficulty of eliminating emissions through other means in these industries.
- Mixed operational track record: several high-profile point-source capture projects have underperformed their designed capture rates or faced extended shutdowns, tempering some of the optimism from earlier project announcements.
Petra Nova, one of the most closely watched large-scale point-source projects, was mothballed for several years following economic pressures before restarting, an experience that industry analysts frequently cite as a cautionary example of how capture project economics remain fragile even at demonstrated technical scale.
Natural gas processing facilities have quietly become one of the more successful point-source capture applications, since separating naturally occurring CO2 from extracted gas is a technically simpler process than capturing combustion emissions, and several long-running projects at gas processing sites have compiled multi-decade operational track records with comparatively little public attention despite representing some of the most consistently reliable capture operations currently running anywhere in the world.
Storage and Sequestration Challenges Underground
Captured carbon dioxide must go somewhere permanent to deliver real climate benefit, and the primary storage approaches each carry their own technical and logistical considerations. Geological sequestration, injecting CO2 deep underground into depleted oil and gas reservoirs or saline aquifers, represents the most common storage method currently deployed, while mineralization, converting CO2 into stable carbonate rock, offers a more permanent but slower-acting alternative.
- Geological storage: injected CO2 is monitored for leakage risk over long time horizons, requiring regulatory frameworks and monitoring commitments that extend far beyond a typical industrial project’s operational lifespan.
- Basalt mineralization: pioneered at scale in Iceland’s CarbFix project, this method converts injected CO2 into solid carbonate minerals within a few years, offering a faster path to permanent storage than traditional geological injection.
- Enhanced oil recovery overlap: some captured CO2 has historically been sold to oil companies for enhanced oil recovery, injecting it into aging oil fields to boost extraction, a practice that critics argue undermines the climate benefit by directly enabling additional fossil fuel production.
- Long-term liability questions: legal frameworks addressing who bears responsibility for stored CO2 decades or centuries into the future remain underdeveloped in many jurisdictions, creating uncertainty for large-scale storage project financing.
Seismic monitoring around injection sites has drawn additional regulatory attention following documented cases of induced minor seismic activity linked to large-scale underground fluid injection in other industrial contexts, prompting storage project developers to build extensive monitoring networks and, in some cases, adjust injection rates specifically to minimize any risk of triggering detectable ground movement near populated areas.
Cost Per Ton Still the Central Problem
Cost remains the single most significant barrier separating carbon capture from a technology capable of meaningful climate impact at global scale. Direct air capture costs have been estimated in the range of several hundred dollars per ton of CO2 removed at current deployment scale, dramatically higher than the price carbon trades for in most existing carbon markets, meaning the economics do not yet work without substantial subsidy or premium voluntary buyers willing to pay well above prevailing carbon prices.
- Direct air capture economics: current costs remain high enough that widespread deployment depends heavily on continued cost reduction through technological improvement and manufacturing scale, a trajectory companies compare to the cost curve solar panels followed over recent decades.
- Point-source cost advantages: capturing CO2 at a concentrated industrial source generally costs less per ton than pulling it from dilute ambient air, though costs still vary substantially by industry and facility design.
- Subsidy dependence: most currently operating and planned projects rely heavily on government tax credits and subsidies to achieve viable project economics, raising questions about long-term commercial sustainability absent continued policy support.
- Learning curve optimism: industry advocates point to historical cost declines in renewable energy technology as evidence that carbon capture costs will similarly fall with deployment scale, though skeptics note carbon capture faces different physical and chemical constraints than solar manufacturing.
Government Incentives Reshaping the Economics
Policy support has become the primary driver of carbon capture project development, especially following the expansion of the United States’ 45Q tax credit, which provides a per-ton financial incentive for captured and stored carbon dioxide. The Inflation Reduction Act sharply increased 45Q credit values and expanded eligibility, triggering a wave of new project announcements across the American carbon capture industry that project developers directly credit to the policy change.
The European Union has pursued carbon capture support through its Emissions Trading System and dedicated Innovation Fund grants, while countries including Norway and the United Kingdom have committed public funding toward carbon capture and storage hub infrastructure intended to serve multiple industrial facilities sharing common transport and storage networks.
This hub model, concentrating storage infrastructure investment around industrial clusters rather than requiring each individual facility to build standalone capture and storage systems, has emerged as a preferred policy approach for reducing the per-project capital cost that has historically limited broader adoption.
Corporate Carbon Credits and Offset Markets
Beyond direct government subsidy, corporate demand for high-quality carbon removal credits has become an increasingly important revenue source for capture project developers, especially as major technology companies commit to ambitious net-zero targets that require purchasing carbon removal to offset emissions they cannot yet eliminate directly.
Microsoft has made some of the largest publicly announced carbon removal purchases, including multi-year agreements with direct air capture companies specifically because the permanence and verifiability of engineered removal compares favorably to more traditional and controversial offset categories like forestry credits.
- Premium pricing for permanence: corporate buyers increasingly favor engineered carbon removal over cheaper nature-based offsets specifically because of stronger permanence guarantees and clearer measurement standards.
- Long-term purchase agreements: several major technology companies have signed multi-year carbon removal purchase agreements, providing capture project developers with revenue certainty that supports project financing decisions.
- Verification standards emerging: third-party verification bodies have developed increasingly rigorous standards specifically for engineered carbon removal, distinguishing it from the more loosely regulated voluntary offset market that has faced credibility criticism in recent years.
Criticism From Climate Scientists and Activists
Not everyone in the climate science and advocacy community views carbon capture technology favorably, and the criticism extends well beyond simple technological skepticism. Some climate advocates argue that carbon capture investment risks functioning as a moral hazard, providing fossil fuel companies and policymakers a justification for continuing or expanding emissions-intensive activity under the assumption that capture technology will address the resulting carbon dioxide later, an assumption critics argue remains unproven at the scale required.
Environmental justice organizations have raised specific and recurring concerns about point-source capture projects located near communities already burdened by industrial pollution, arguing that capture technology addresses carbon dioxide specifically while doing nothing to reduce the other pollutants, including particulate matter and toxic emissions, that continue affecting nearby residents’ health regardless of a facility’s carbon capture rate.
This critique has become especially prominent in debates over capture retrofits proposed for older industrial facilities located in historically disadvantaged neighborhoods already carrying a disproportionate pollution burden.
Emerging Technologies Worth Watching
Beyond the currently dominant liquid solvent and solid sorbent approaches, researchers are developing alternative capture methods that could eventually improve on current cost and energy efficiency limitations. Mineralization-based direct capture, electrochemical capture methods that use renewable electricity more directly in the extraction process, and bioengineered approaches using modified algae or enzymes each represent active areas of research still years away from commercial-scale deployment.
- Electrochemical capture: emerging methods aim to use electricity more directly in the CO2 extraction process, potentially reducing the energy losses associated with traditional thermal regeneration cycles.
- Ocean-based capture: some researchers are exploring methods to remove CO2 dissolved in seawater, leveraging the ocean’s role as a large natural carbon reservoir, though environmental impact questions remain understudied.
- Modular smaller-scale systems: several startups are pursuing smaller, more distributed capture units rather than the mega-facility model, betting that manufacturing scale and rapid deployment across many sites could outpace the cost reduction achievable through a smaller number of very large plants.
- Enhanced weathering approaches: some researchers are studying accelerated mineral weathering, spreading crushed rock over agricultural land to absorb atmospheric CO2 over time, as a lower-tech complement to engineered capture systems.
Final Thoughts
Carbon capture technology occupies a truly difficult middle ground between demonstrated scientific viability and the enormous scale-up challenge still standing between current deployment and any notable global climate impact. The engineering works, storage methods have proven durable where properly implemented, and government policy has begun channeling real capital toward expansion, but costs remain high enough that the industry still depends heavily on subsidy and premium corporate buyers rather than standing on independent economic footing.
Whether carbon capture becomes a truly important climate tool or remains a comparatively marginal technology serving a narrow set of hard-to-decarbonize industrial applications will likely depend on cost trajectories over the next decade, a period during which continued skepticism from parts of the climate community will remain a healthy counterweight to industry optimism that has, at times, outpaced real deployment progress on the ground.
Frequently Asked Questions
Does carbon capture technology work?
Yes, both direct air capture and point-source capture technologies function as designed and have demonstrated the ability to remove and permanently store carbon dioxide at operating facilities around the world. The open question is not whether the technology works, but whether it can scale to a size and cost that noticeably affects global emissions.
How much carbon dioxide can current facilities capture?
Current large-scale facilities capture volumes measured in tens of thousands to low millions of tons annually, a small fraction of the tens of billions of tons of global annual emissions, meaning existing capacity remains far below what would be needed for significant climate impact on its own. Substantial scale-up would clearly be required for the technology to noticeably offset global emissions levels overall.
Is carbon capture a distraction from reducing emissions directly?
This remains a hotly contested question among climate scientists and policymakers today, with critics arguing it risks delaying direct emissions reductions while supporters view it as a necessary complement for hard-to-decarbonize sectors like cement and steel production. Most mainstream climate frameworks treat capture as a supplement to, not a substitute for, aggressive direct emissions reduction.
Why is direct air capture so much more expensive than point-source capture?
Ambient air contains a far lower concentration of carbon dioxide than an industrial exhaust stream, requiring more energy and processing per ton of CO2 captured from dilute open air compared to a concentrated smokestack source. This fundamental physical difference explains much of the persistent cost gap between the two approaches.
Who is paying for carbon capture projects right now?
Funding comes from a combination of government tax incentives, especially the expanded 45Q credit in the United States, direct government grants in Europe, and corporate carbon removal purchase agreements from companies pursuing net-zero commitments. Few, if any, large-scale projects currently operate profitably without this combination of policy and voluntary corporate support.
What happens to carbon dioxide after it is captured?
Captured CO2 is typically either injected deep underground into geological formations for long-term storage, converted into stable mineral rock through processes like basalt mineralization, or in some cases sold for industrial uses including enhanced oil recovery, a practice that draws criticism for its connection to additional fossil fuel extraction.