Carbon capture has attracted over $40 billion in global investment, yet it currently captures and stores less than 0.1% of annual global CO2 emissions. The gap between what this technology promises and what it delivers is enormous, and the reasons span physics, economics, infrastructure, and a track record of high-profile failures. Here’s why many experts and analysts argue it cannot scale to meet climate targets.
The Energy Penalty Is Baked Into the Physics
Separating CO2 from other gases takes a lot of energy, and there’s no engineering trick that eliminates this cost. The standard chemical solvent used in most capture systems requires roughly 4 gigajoules of thermal energy per metric ton of CO2 removed. Next-generation solvents may bring that down to about 2.6 gigajoules per ton, but that’s still a massive energy draw. A coal plant fitted with carbon capture has to burn significantly more fuel just to power the capture equipment, which means more emissions from the extra fuel, which partly defeats the purpose.
Direct air capture, which pulls CO2 straight from the atmosphere rather than from a smokestack, faces an even steeper thermodynamic challenge. Flue gas from a power plant contains CO2 at concentrations of 10 to 15 percent. Ambient air contains about 0.04 percent. Extracting a dilute gas from a vast volume of air requires vastly more energy per ton. This isn’t a problem that better engineering solves completely. It’s a constraint set by thermodynamics.
The Track Record Is Poor
Large-scale carbon capture projects have a pattern of cost overruns, missed targets, and outright shutdowns. A comprehensive review published in 2025 found that projects “hailed as successful often fall short when scrutinized against durability, scale, and emissions offset claims.” The recurring problems are the same ones that plagued early flagship projects: equipment underperforms, maintenance costs balloon, and capture rates fall well below projections.
These aren’t isolated bad luck stories. They reflect structural problems with bolting complex chemical processing systems onto industrial facilities that weren’t designed for them. The review identified “recurring patterns of cost overruns, suboptimal capture rates, geological uncertainties, and public liability transfer” across the global portfolio of CCS projects. After decades of development, the technology still captures a vanishingly small fraction of what the world emits each year.
The Scale Required Is Unrealistic
In 2020, global carbon capture capacity stood at roughly 40 million metric tons of CO2 per year. The IEA’s Net Zero by 2050 roadmap calls for that to reach 1,670 million metric tons by 2030 and 7,600 million metric tons by 2050. That’s a 40-fold increase in the next few years and a 190-fold increase over three decades.
For context, the entire global oil and gas industry took over a century to build its current infrastructure. Carbon capture would need to build out pipeline networks, storage sites, and capture facilities at a pace that has no precedent in energy history. The IEA scenario also calls for 630 million metric tons of direct air capture alone by 2050, a technology that currently operates at a tiny fraction of that scale and remains extraordinarily expensive.
Costs Remain Stubbornly High
Post-combustion capture at a power plant costs in the range of $50 to $120 per ton of CO2 under optimistic assumptions, though real-world projects have come in far higher. Direct air capture is dramatically more expensive. First-of-a-kind commercial plants are estimated at $400 to $700 per ton. Even bullish projections from the IEA place costs at $125 to $335 per ton, and Climeworks, one of the leading companies in the field, operates at roughly 580 euros per ton at its current scale.
To put those numbers in perspective, global CO2 emissions are around 37 billion metric tons per year. Even capturing just one billion tons through direct air capture at $300 per ton would cost $300 billion annually. That’s more than the entire world currently spends on renewable energy subsidies. Meanwhile, solar and wind power avoid emissions at a fraction of that cost per ton.
Most Captured CO2 Goes Back Into Fossil Fuels
A detail that undercuts the entire climate rationale: the majority of captured CO2 is not permanently stored underground. It’s pumped into aging oil fields to push out more crude oil, a process called enhanced oil recovery. Data from the U.S. National Energy Technology Laboratory shows that 17 of 19 large-scale U.S. carbon capture projects use captured CO2 for this purpose. Globally, enhanced oil recovery has consumed about 50 million metric tons of CO2 per year, representing the dominant commercial use of captured carbon.
Burning the additional oil extracted this way releases CO2 back into the atmosphere. Some of the injected CO2 stays underground, but the net climate math is questionable at best. Carbon capture that enables more oil production is not a climate solution. It’s a subsidy for the fossil fuel industry wrapped in environmental branding.
Infrastructure Gaps and Safety Concerns
Scaling carbon capture requires an extensive network of high-pressure pipelines to move CO2 from capture sites to storage locations. The U.S. currently has a limited CO2 pipeline system, and an analysis of federal safety data covering 1991 to 2024 found 121 reported accidents across that network, releasing roughly 19,700 metric tons of CO2 and causing $6.96 million in damages.
Perhaps more concerning is how those leaks were detected. Automated monitoring systems caught fewer than 20 percent of CO2 releases. In 13 percent of accidents, members of the public reported the leak before any instrument did. CO2 pipelines follow a “bathtub” failure pattern: higher leak rates in the first decade of operation, a quieter middle period, then rising failure rates again after 30 to 40 years as infrastructure ages. Building thousands of miles of new CO2 pipelines through populated areas raises real safety and regulatory hurdles that proponents rarely address in their timelines.
Water and Chemical Waste
Carbon capture isn’t just energy-intensive. Solvent-based direct air capture systems, which use liquid chemical solutions, consume 3 to 12 times more water per ton of CO2 than solid sorbent systems. In a world already facing water stress in many regions, scaling these technologies adds another resource competition.
The chemical solvents themselves degrade over time as they react with impurities in flue gas, producing a stew of waste compounds. Pilot plant data shows that the solvent accumulates sulfate, nitrate, and chloride salts, along with organic degradation products like formate. Dissolved metals including iron, chromium, and nickel build up in the solvent over hundreds of operating hours. While concentrations of the most toxic metals like lead and arsenic stayed below hazardous waste thresholds in testing, the sheer volume of degraded solvent that a commercial-scale plant would generate creates a significant waste management challenge.
Geological Storage Is Promising but Unproven at Scale
The one genuinely encouraging piece of the picture is underground storage itself. A study of a natural CO2 reservoir in Arizona, where CO2 has been leaking through faults for 420,000 years, found that even at a geologically flawed site (one that would never be selected for engineered storage), the time-averaged leakage rate was below 0.01 percent per year. That’s within the threshold scientists consider adequate for climate mitigation, which requires secure storage for at least 10,000 years.
But identifying suitable geology and proving that engineered storage sites will perform as well as natural analogs are different challenges. Every proposed site needs extensive characterization, monitoring, and long-term liability frameworks. The handful of dedicated storage projects operating today don’t come close to demonstrating that thousands of sites worldwide can be developed safely and quickly enough to matter.
The Opportunity Cost Problem
Every dollar spent on carbon capture is a dollar not spent on solutions with a proven track record. Solar panels, wind turbines, battery storage, grid upgrades, building electrification, and energy efficiency improvements all reduce emissions at lower cost and with fewer technical risks. Carbon capture competes for the same capital, the same political attention, and the same engineering talent.
Carbon capture may have a narrow role in sectors where emissions are genuinely hard to eliminate, like cement and steel production. But as a broad climate strategy, the numbers simply don’t add up. The technology is too expensive, too energy-intensive, too slow to scale, and too dependent on infrastructure that doesn’t yet exist. Its most prominent use case so far has been extracting more oil. For the vast majority of emissions, avoiding them in the first place is faster, cheaper, and more reliable than trying to recapture them after the fact.