If the human world is to mitigate the planet’s ongoing climate changes in a substantial way in coming years, one of the key instruments toward that end will be carbon capture technology: the capture of CO2 out of the air and the preservation of the resulting carbon in a sequestered or alternatively a useful form on the surface.
Of course planting a tree is a low-tech way of capturing carbon. Most climate change experts contend, though, that the human species cannot plant enough trees quickly enough to make the impact necessary. One must also consider that trees are not “sequestered.” In the event of a fire, for example, the CO2 is released again into the atmosphere.
Technological methods of carbon capture can be either direct air capture or point source. Point source capture involves a system that grabs the CO2 out of an exhaust, as at a chemical plant.
Direct air capture involves the use of a sorbent to pick up CO2 in the wind. The sorbent can periodically be cleansed of the carbon and re-used. The carbon can then be compressed and sequestered.
Strange New Worlds:
Direct air capture will likely become a mass activity when it becomes profitable. That involves the use, not merely the sequestration, of the carbon obtained. It also involves getting the cost of DAC lower than the present cost of carbon in the marketplace. That is proving to be a challenge.