Few technologies in the sustainability landscape divide opinion as sharply as carbon capture. To its advocates, it is indispensable — one of the only ways to decarbonise industries that have no other path. To its critics, it is a costly licence to keep polluting, a technological fig leaf for fossil interests. The striking thing is that both camps can point to real examples that prove their case. That is because the sustainability verdict on carbon capture depends almost entirely on one question: where you point it.
Carbon capture, utilisation and storage (CCUS) is not a single thing applied uniformly. It is a family of technologies deployed in wildly different contexts, and the same equipment can be genuinely climate-critical in one setting and genuinely counterproductive in another. Understanding that distinction is the whole of the analysis.
The distinction that decides everything
Attach carbon capture to a coal power plant to extend its operating life, and the skepticism is warranted. You are spending energy and capital to keep a high-emitting asset running, often capturing only a portion of its emissions, when cheaper and cleaner alternatives to that power exist. The climate case is weak, and the "clean coal" framing has rightly drawn scrutiny.
Now point the same technology at a cement kiln, a steel furnace, or a chemical plant — industries where the carbon dioxide is released by the chemistry of the process itself, not just by burning fuel, and where no mature alternative exists. Here carbon capture becomes one of the few tools that can actually abate otherwise unavoidable emissions. The climate case is strong.
Identical technology. Opposite verdict. This is why carbon capture cannot be assessed by the label on the technology; it has to be assessed by the target, the alternative, and the evidence. A headline announcing "carbon capture project" tells you almost nothing until you know what it is capturing carbon from and what would otherwise happen.
Why CCUS demands an anti-greenwashing lens
No sustainability technology attracts more greenwashing risk than carbon capture, and for understandable reasons — it is complex, the numbers are hard for outsiders to verify, and the incentives to overstate its benefit are strong. Rigorous due diligence therefore has to count the whole ledger, not the headline.
The first question is net capture. Capturing carbon takes energy, and that energy often produces emissions of its own. A project that captures a large gross quantity of carbon dioxide while consuming carbon-intensive energy to do so may deliver a far smaller net reduction than its headline suggests. Honest accounting subtracts the energy penalty.
The second is permanence. Captured carbon that is stored deep underground in stable geology stays out of the atmosphere for the long term. Captured carbon that is used in ways that quickly re-release it — some industrial uses effectively return the carbon to the air — provides a much weaker climate benefit. "Utilisation" and "storage" are not equivalent, and lumping them together obscures the difference.
The third is the enabled-emissions question, the hardest and most important. Does the project genuinely abate emissions that could not otherwise be avoided, or does it provide cover for continued emissions that could have been eliminated more cheaply another way? A capture project that keeps an avoidable emitter running is a different proposition from one that abates a genuinely unavoidable source.
A CCUS project claiming "X tonnes captured" while its own process emissions, its enabled emissions, and the permanence of its storage all go uncounted is telling a fraction of the story. Serious analysis counts the whole thing, and maps it against genuine climate-mitigation contribution rather than gross capture figures.
Point-source versus direct air capture
Within CCUS, two broad approaches sit at very different points on the cost-and-maturity spectrum, and conflating them is a common error.
Point-source capture pulls carbon dioxide from a concentrated exhaust stream — a cement plant's flue, a chemical process vent. Because the carbon is concentrated, it is relatively cheaper to capture, and this is where the near-term, defensible case is strongest, especially at hard-to-abate industrial sources.
Direct air capture (DAC) extracts carbon dioxide directly from the ambient atmosphere, where it is extraordinarily dilute. That makes it far more expensive and energy-intensive per tonne, and its case is justified only where nothing else can reach — for genuinely unavoidable or historical emissions, and only when powered by abundant clean energy. DAC is important for the long term, but treating it as a cheap, near-term climate fix misreads the physics and the economics.
The infrastructure that makes or breaks a project
Capture is only half the chain. You cannot store carbon you cannot move, and you cannot claim a climate benefit for carbon that is captured but not durably sequestered. Transport pipelines and storage sites — the geology to hold carbon permanently — are essential, underbuilt, and often the real constraint on a project's viability.
This is why a capture project with a secured, permanent storage route is a fundamentally different proposition from one that captures carbon on the assumption that transport and storage will materialise. The full chain has to exist for the sustainability claim to hold.
Reading CCUS with discipline
Carbon capture rewards discipline over both enthusiasm and cynicism. The blanket claim that it is a scam is as unhelpful as the claim that it is a universal solution. The honest position is that CCUS is essential for a specific, identifiable set of hard-to-abate sources, questionable for many others, and only ever as good as the net accounting and permanent storage behind it.
For investors, industrial buyers, and policymakers, the questions that carry the most signal are concrete. What exactly is the carbon being captured from, and is that source genuinely unavoidable? What is the net capture after the energy penalty? Is the storage permanent, or is the carbon merely used and re-released? And does the full transport-and-storage chain actually exist? A project that answers these well is infrastructure worth backing. One that cannot is a claim that will not survive scrutiny — and increasingly, scrutiny is exactly what regulators, buyers, and disclosure regimes are bringing.