The level of carbon dioxide in the atmosphere is now climbing above 400 parts per million. That measure is by volume, (not by mass). 400 ppm is roughly twice the concentration it was at the beginning of the industrial revolution, two hundred years ago. One of the feel-good solutions to the greenhouse gas problem now being pushed is “carbon capture”, that is, removing CO2 from the atmosphere and locking it up somewhere, say in underground rock formations. This is not physically impossible, after all, plants have been doing it for millions of years, they use the energy in sunlight to convert CO2 to sugar, cellulose and limestone.

400 ppm is still a tiny concentration, but the greenhouse properties of the gas are so powerful that it is still a significant figure of severe environmental consequence.
Furthermore, the CO2 concentration is now so elevated that even if we could somehow magically stop adding any more to the atmosphere, the amount already there would still have a disastrous effect on our climate. Any more only makes things worse.

So, is it possible to remove CO2 from the atmosphere so it can be sequestered, using some sort of mechanical, chemical or industrial process? The idea is to suck up atmosphere and somehow remove the CO2 that is in it, by some mechanical or chemical process, and then placing all that CO2 somewhere where it can do no harm, say by pumping it underground. The problem is in the pumping. For every molecule of CO2 removed from the atmosphere, 2500 molecules of air will have to be pumped through our plant or facility. To put it another way, for every cubic meter of CO2 removed, 2500 cubic meters of air will have to be processed. Pumping that much air requires lots of energy, and then pumping the CO2 to a safe place requires even more. Even if the process of removing the CO2 from the atmosphere is somehow, magically, energy-free, just the pumping alone will require massive amounts of energy. Even more energy will be required to build the plants that do all this work. To remove a sufficient amount of CO2 to make this feasible will require pumping a significant portion of the earth’s atmosphere through the plant. You can crunch those numbers if you like, but I suspect its going to be a long, long time. To get back to pre-industrial CO2 levels, you would have to pump half the atmosphere of the planet through your facilities in order to remove the CO2 that has been generated by two centuries of industrial revolution, coal-fired power plants, internal combustion engines, cement production. And where would you put it all? And if your magic removal process is, say, only 50% efficient, you’re going to have pump all that air twice.

Its not going to ever happen. And anyone who who thinks this is a viable technical solution to the greenhouse problem is blowing carbon dioxide out his ass. The fact that this solution is being advanced by people who supposedly have degrees in chemistry or engineering (and work for energy companies) tells me it is a deliberate fraud, manufactured to distract us from the real problem. There is only one way to sequester carbon dioxide from the atmosphere: Plants. That’s how all those coal beds and oil pools and limestone deposits got created in the first place. And that took hundreds of millions of years.