Direct air capture (DAC) is an approach designed to extract CO2 directly from the atmosphere using chemical reactions. Unlike traditional carbon capture, which traps emissions at the source, DAC systems can be placed anywhere in the world to scrub legacy emissions right out of the open air. The process typically relies on large industrial fans to pull air through a contractor, where it interact with a chemical medium that selectively binds with the CO2. Once captured, the chemical system is heated or treated to release the pure CO2, which is then compressed and permanently stored underground in deep geological formations or repurposed for industrial products like synthetic fuels and building materials.

As a critical tool for reaching global net 0 goals, DAC offers the unique advantage of addressable flexibility, but it faces significant economic and energetic hurdles. Unlike natural carbon sinks like forest, DAC facilities require a very small geographic footprint and do not compete with agriculture for land or water resources. However, because CO2 is highly diluted in the open atmosphere, the process requires and immense amount of energy to capture and separate the gas efficiently. Consequently, the technology must be powered entirely by renewable or low-carbon energy sources to ensure a net-negative carbon footprint.