[scottdupoy]

> The gasoline produced from carbon is then intended for burn...

If it's captured from the atmosphere and then burnt then surely it's zero-sum (apart from the energy cost of capture). Is this not better than releasing historically captured fossil fuels with a larger net increase in atmospheric levels?

If the capturing process is net-negative in terms of CO2 emmissions then perhaps we could invest in capturing more than we require for fuel - ie pull the CO2 out of the atmosphere and stockpile it in non-gaseous form. My experience is that people are willing to pay to clear their conscience and feel that they're making a positive climate change impact, but irrationally very resistant to changing their own behaviour.

[dagss]

Plenty of projects for harvesting CO2 getting prototyped -- and my point is the OP is not one of them. If the purpose is just storage and not making fuel, there are other ways (like liquid CO2).

[chriswarbo]

That's all true, but it depends completely on the cost. Fuel is a fungible good: one barrel of, say diesel, is equivalent to any other (assuming they're the same "grade", etc.).

Stockpiling a barrel of fuel pulled from the air is the same as stockpiling a barrel of fuel dug out of the ground (assuming it would otherwise have been burned): both result in 1 barrel-of-fuel-worth of CO2 in a stockpile rather than the atmosphere.

It takes a lot of energy to extract fuel out of the air, so buying a barrel of fuel-from-the-ground is currently cheaper. Hence we can stockpile more of it for the same cost, and have a bigger effect on the climate.

We can go even further: fuel-from-the-ground was already stockpiled, as fuel-in-the-ground. Locating, extracting and refining it takes a lot of energy, so buying a barrel of fuel-in-the-ground and leaving it alone is much cheaper than buying fuel-from-the-ground or fuel-from-the-air. It's also has lower maintenance costs.

Activities like carbon sequestering or extracting fuel from the atmosphere are nothing more (or less) than methods for redistributing energy and costs.

This redistribution is useful for those cases where fuel is a necessity, e.g. jumbo jets. Extracting that fuel from the atmosphere using renewable power (carbon negative) would allow jumbo jets (carbon positive) to be overall carbon neutral. From a cost and energy perspective that would be hugely inefficient compared to simply powering the planes with renewable energy directly; the only reason it should be taken seriously at all is because electric jumbos are not an option (and won't be for a long time, due to physics, battery chemistry, etc.).

In any situation where renewable is a viable option (e.g. electricity grids, cars, etc.) then these redistribution schemes make no sense. Every step in a process loses some efficiency; since the whole point is to reduce atmospheric CO2, and atmospheric CO2 depends on energy usage, introducing inefficiencies to "clear our conscience" is counter productive.

Of course there are some nuances. For example, it might make sense to have nuclear plants pulling fuel out of the air for stockpiling (nuclear works best with a steady demand). We could think of this as plundering the nuclear fuel of future generations (the energy we leave in our stockpiled fuel won't match that of the nuclear fuel used to make it, due to inefficiencies). This may be desirable, if it's cheaper to spend that fuel fixing our climate mess now, than it would be for those generations to fix it themselves if we burden them with it.

(Note that burning any of that nuclear-aquired fuel-from-the-air also makes no sense if we could have just used the nuclear power directly)