CCUS captures CO₂ from point sources (industrial smokestacks) or the atmosphere, then permanently stores it in geological formations underground or converts it to other products. The IPCC’s Sixth Assessment Report (AR6) is explicit: achieving the 1.5°C warming target requires CCUS (especially Direct Air Capture) in almost all feasible pathways — because many emission sources (aviation, cement, steel) are extremely difficult to directly electrify.
## Main Technical Routes
**Point-source capture (post-combustion/pre-combustion)**: CO₂ captured at the exhaust of fossil fuel power plants or industrial facilities. Existing technology (amine scrubbing) operates at commercial scale, but energy penalty is high (consuming ~20–30% of plant output) and retrofit costs are substantial. Global operating examples: Boundary Dam (Canada, coal + CCS), Quest (Canada, oil sands + CCS, Shell-operated).
**Direct Air Capture (DAC)**: capturing CO₂ directly from ambient air (~420 ppm concentration); lower efficiency and higher cost (~$400–1,000/tonne CO₂ versus $50–150/tonne for point-source capture) but deployable anywhere — a key technology for achieving “carbon removal.” Leading companies: Climeworks (Switzerland, operating commercial DAC + storage plant in Iceland), Carbon Engineering (acquired by Occidental).
**Bioenergy with Carbon Capture and Storage (BECCS)**: plant growth absorbs CO₂ → biomass combusted for power/heat → captured CO₂ stored, achieving net negative emissions. Theoretically important for “negative emissions,” but large-scale biomass cultivation’s land competition (with food production and ecosystem preservation) is a central controversy.
## Disputes and Reality
CCUS supporters (including major oil companies) argue it’s an indispensable bridge technology. Critics argue it provides fossil fuel industries a justification for extending existing business models; current global CCS annual sequestration of ~45 million tonnes versus ~37 billion tonnes annual global emissions (roughly 800× gap) shows CCUS cannot be over-relied upon.
China has multiple CCUS demonstration projects (Yanchang Petroleum in Shaanxi, CHN Energy coal power CCS), but overall scale remains early-stage. The “14th Five-Year Plan” includes CCUS as an important technology direction, but actual progress lags significantly behind climate target requirements.
See [Solar Energy Technology](https://sunqi.org/solar-energy-technology-advances-en/), [Hydrogen Economy](https://sunqi.org/hydrogen-energy-economy-en/), and the [IPCC AR6](https://www.ipcc.ch/assessment-report/ar6/).
