way to tackle climate change: just pass
ambient air over chemicals that absorb the
CO2 driving global warming, and then use or
store the CO2. DAC differs from the
better-known carbon capture and storage
(CCS) in that it can be done anywhere, not
just at big sources of CO2 such as power
stations. It’s more effective than natural CO2
‘scrubbing’ using trees and plants, and can
be performed where the CO2 is most easily
stored or re-used.
Like CCS, however, DAC faces the
problem of ensuring the CO2 never escapes.
Unlike CCS at power stations, DAC must
be effective at removing the far more dilute
CO2 in ambient air. This demands special
equipment and chemicals, plus renewable
energy sources producing zero CO2. That
has led to grave doubts about the
economic viability of DAC. For now, it
remains an intriguing but impractical
remedy for global warming.
