How does carbon capture and storage aim to keep carbon dioxide out of the atmosphere?

Carbon capture and storage (CCS) is a three-stage process designed to mitigate global warming by preventing carbon dioxide (CO₂) from entering the atmosphere.1

The process functions through the following stages:

• Capture: CO₂ is separated from industrial or power plant emissions using methods such as post-combustion, pre-combustion, or oxyfuel combustion. Additionally, direct air capture can extract CO₂ directly from the ambient air.2
• Transport: Once captured, the CO₂ is compressed into a liquid state and transported to a designated storage site.12
• Storage: The CO₂ is injected into isolated, long-term storage locations deep underground (typically at least 1 km deep), such as depleted oil and gas reservoirs, deep saline formations, or porous sedimentary rock strata.34

By sequestering the gas in these geologic formations, CCS ensures that carbon remains isolated from the atmosphere. Some variations, known as carbon capture, utilization, and storage (CCUS), further repurpose captured carbon into products like concrete or plastics before storing the remainder.415