It is well established that this planet has a problem with rising concentrations of carbon dioxide (CO2) in the atmosphere. While the most commonly explored solutions to this problem involve technological and conservation efforts that decrease the rate at which CO2 is released into the air, there is another: directly remove CO2 from the atmosphere. Once removed, the CO2 can be sequestered or converted into something useful such as a fuel or material.
Researchers have considered this second option for many years, but the technologies needed to pull CO2 from air have been generally considered too expensive to be realistic, with costs generally predicted to be > $600 per ton of CO2 harvested from the air. Excitingly, it has been recently reported that the cost of direct air capture (DAC) can be substantially reduced. As discussed in the following editorial on Nature.com and described in detail in an article published in the peer-reviewed journal Joule, scientists and engineers at a Canandian company, Carbon Engineering, have performed a technoeconomic analysis on a DAC system based on well-established commercial technologies that predicts carbon capture at levelized costs of $94- $214 per ton of CO2.
For perspective, if the captured CO2 were converted into a fuel such as methanol, the capture cost would add 0.4-0.8 cents per gallon of methanol produced. In North American, methanol currently sells for ~ $1.64 / gal., so making methanol from DAC CO2 using conventional methods would currently add ~ 25-50 % to the cost. Not bad! As DAC and CO2 conversion technologies continues to improve, such a circular Carbon technology is very likely to become a reality.