Carbon Capture & Storage
Roughly 49 million tonnes per year of CO₂ capture capacity is operational globally — about 0.13% of annual fossil emissions. The IEA Net Zero scenario calls for 1,200 Mt/year by 2030 and 6,200 Mt/year by 2050. The pipeline of announced projects has grown sharply since 2020 but most are pre-FID and timelines slip routinely.
Key insights
Most current CCS is for enhanced oil recovery
Of ~49 Mt/yr operational capacity, ~70% involves CO₂ used for enhanced oil recovery (EOR) — pumped into mature oilfields to push out more crude. The net climate benefit is contested; the captured CO₂ stays underground but the extra oil produced is then burned. Dedicated geological storage (saline aquifers) makes up a smaller share but is growing — Norway's Sleipner has stored 25+ Mt since 1996; the UK's Endurance and US Class VI permits are scaling.
Direct air capture is small but accelerating
DAC pulls CO₂ from ambient air at ~420 ppm — physically harder than capturing 12% flue gas. Operational DAC capacity reached ~10,000 tonnes/year in 2024 across Climeworks, Carbon Engineering, Global Thermostat and a few others. The US DAC Hubs programme awarded $3.5B to four projects targeting megaton-scale by the late 2020s. Costs remain $400–600/t but are projected to fall toward $100–200/t with scale.
Application determines economics
Capture from concentrated streams (ammonia plant CO₂, ethanol fermentation, gas processing) costs $20–50/t — already economic with tax credits like the US 45Q ($85/t for sequestration). Capture from flue gas at power plants and steel furnaces is $50–120/t. Cement is harder at $70–150/t (process emissions, not just combustion). DAC sits highest. The cost gradient determines the deployment order.
Operational CCS capacity 2010–2024
Million tonnes CO₂ captured per year
Key Finding: Capacity has roughly doubled since 2018. Headline announcements have grown faster than commissioned plants.
Capture cost by application (USD per tonne CO₂)
Levelized cost ranges, 2024 IEA mid-points
Key Finding: Industrial-grade concentrated streams capture for under $50/t; DAC remains an order of magnitude more expensive.
Methodology & caveats
CCS vs CCU vs CDR
CCS (carbon capture and storage) injects CO₂ into geological formations for permanent sequestration. CCU (carbon capture and utilization) converts captured CO₂ to products (synthetic fuels, urea, plastics) — many of these re-release the CO₂. CDR (carbon dioxide removal) describes anything that removes already-emitted CO₂ from the atmosphere — DAC, BECCS, enhanced weathering, ocean removal, afforestation.
Storage durability
IPCC AR6 considers >1,000-year geological storage 'permanent' for accounting purposes. Saline aquifers and depleted oil/gas reservoirs are the leading storage options. Mineralization (locking CO₂ into rock — Iceland's Carbfix) is the most permanent but slowest. Leakage monitoring requires multi-decade verification — a major implementation challenge.
BECCS and the negative-emissions question
Bioenergy with carbon capture and storage (BECCS) captures CO₂ from burning biomass, producing 'negative emissions' (the biomass absorbed atmospheric CO₂ during growth, the CCS prevents it from returning). The accounting is sound only if the biomass is sustainably sourced — a constraint that limits scalability. Net Zero pathways depend on BECCS or DAC to balance residual hard-to-abate emissions; whether either scales fast enough is contested.