Eliminating carbon dioxide emissions from global energy and industrial processes is a huge undertaking. Delays abound. Renewable energy deployment needs to speed up. Electricity grids are bottlenecked. Electric vehicle sales growth has slowed. And home heat pumps are barely out of the starting gates.

Transition troubles — as well as the fact that some emissions will be very difficult to eliminate completely — are driving interest in direct air capture (DAC), a nascent technology that sucks CO₂ straight out of the air and stores it underground.

How does it work?

In outline, DAC is a simple enough proposition, requiring only modular units containing a fan and a filter. The fan draws air in and through the filter, which captures the CO₂ molecules. The filter is a solid material or a chemical solution that binds to the CO₂ and, once it can absorb no more, can be heated to release the gas.