Example
Combined with durable storage, it can provide carbon dioxide removal.
The catch
Energy demand, source of power and storage performance affect net benefit.
In more depth
Direct air capture, explained.
Direct air capture is hard because CO₂ makes up only a tiny fraction of air, so machines must move enormous volumes of it to catch each tonne. That takes far more energy than capturing CO₂ from the concentrated exhaust of a chimney, and the method remains expensive and small in scale. Plants use either liquid solvents or solid materials that bind CO₂ and release it again when heated.
Its strengths are measurability and flexibility. Captured CO₂ is easy to meter, and plants can sit beside clean power and suitable geology. The removal claim depends on where the gas goes. Stored underground, it can deliver durable carbon dioxide removal with strong permanence, while CO₂ sold for synthetic fuel or fizzy drinks returns to the air within months or years.