How Carbon Capture Works — and Whether It Can Actually Help

Context: a technology at the centre of the climate debate

Carbon capture sits at one of the most contested crossroads in climate policy. To some, it is an essential tool for tackling emissions that cannot be eliminated any other way. To others, it is a costly distraction that lets polluters carry on polluting. Both views contain real truth, which is exactly why the debate is so heated. As the UK and other governments commit serious money to carbon capture, understanding what the technology actually does, what it has genuinely achieved, and where the honest disagreements lie is essential for anyone trying to judge whether it deserves a place in climate strategy — or whether the money would be better spent elsewhere.

The data: what carbon capture is and what it has achieved

Carbon capture and storage (CCS) refers to technologies that trap carbon dioxide — either at the point of emission or directly from the atmosphere — and store it so it does not contribute to warming. There are two broad approaches, suited to different jobs:

Point-source capture with geological storage is a genuinely proven technology. Norway's Sleipner project has been injecting captured CO2 into a deep sandstone formation beneath the North Sea since 1996 — nearly three decades demonstrating that CO2 can be captured, transported and stored underground for the long term. Direct Air Capture is far newer and far more expensive: because atmospheric CO2 is so dilute, pulling it from ambient air currently costs an estimated $300-$1,000 per tonne, making it a promising but not yet scalable tool for large-scale removal.

What's changing: from demonstration to deployment

The UK moved carbon capture from research into serious policy in 2023, committing billions of pounds to develop industrial capture "clusters" — shared CO2 capture, transport and storage infrastructure serving groups of industrial emitters, with early projects planned around Teesside, the Humber and Merseyside. The logic is that heavy industry concentrated in these regions is genuinely hard to decarbonise by other means, and that shared infrastructure spreads the high fixed costs across multiple emitters. Similar deployment efforts are underway internationally, and the IPCC's own net-zero pathways consistently assume some role for carbon capture and removal — reflecting a scientific consensus that at least some CCS is likely to be necessary, even as its exact scale is debated.

"The honest position is that we probably can't reach net zero without some carbon capture — there are industries we don't yet know how to fully decarbonise otherwise — but also that it can't be an excuse to avoid cutting emissions at source, which remains far cheaper and more reliable. It's a supplement, not a substitute." — a framing consistent with how the IPCC and IEA characterise CCS's realistic role.

The genuine controversy — and what it means for you

The central argument against carbon capture is not that the technology doesn't work, but that it might be used to justify continued fossil fuel use when the priority should be eliminating emissions at their source. Critics point to a long history of CCS projects over-promising and under-delivering, and to the risk of "moral hazard" — the idea that the mere existence of a cleanup technology reduces pressure to prevent the pollution in the first place. Proponents respond that some emissions, from cement, steel and certain chemical processes, are genuinely very hard to eliminate, and that removing historic and residual CO2 will be needed regardless. For you as a citizen and taxpayer, the practical stake is whether the substantial public money going into carbon capture delivers real, verified emissions reductions, or becomes an expensive way of appearing to act while emissions continue. That is a reasonable question to hold governments to. Our related explainers on what net zero actually means and the UK's progress toward it provide the wider context, and our piece on carbon offsetting covers a related and similarly contested approach.

It also helps to be clear about scale, because this is where much of the honest scepticism lives. The total amount of CO2 captured and stored worldwide each year remains a tiny fraction of global emissions — measured in tens of millions of tonnes against annual emissions of tens of billions of tonnes. For carbon capture to matter for the climate rather than just for individual facilities, deployment would need to grow by orders of magnitude, quickly, and at costs that make it viable without permanent, very large subsidy. That is a genuinely open question. The technology working at a single site, as Sleipner has for decades, is not the same as it working at the planetary scale the climate challenge demands. This gap between proven-at-a-site and needed-at-scale is the crux of the whole debate: optimists see a technology ready to be scaled up with enough investment, while sceptics see decades of promises that captured carbon would soon make a real dent in emissions, promises that have so far not been met at anything like the necessary scale.

What to watch next

Watch whether the UK's carbon capture clusters deliver on schedule and at the promised cost, since their success or failure will be a major test of whether CCS becomes a real pillar of climate policy or another over-hyped technology. Watch the cost trajectory of Direct Air Capture, which needs to fall dramatically to play a meaningful role in removing CO2 at scale. Watch, critically, whether captured carbon is genuinely used to reduce net emissions rather than to enable continued or increased fossil fuel extraction — some CO2 has historically been used to pump more oil out of the ground, which undercuts the climate rationale. And watch the balance in overall climate policy between capture and prevention: the strongest position, on the current evidence, treats carbon capture as a necessary supplement for the hardest-to-abate emissions, never as a reason to slow the far cheaper and more certain work of cutting emissions at source.