[betwixthewires]

So follow up question, wasn't the carbon in oil itself sequestered from the carbon cycle? If so, this would be a reversal of that sequestration and not introduction, right?

Maybe if you want to remove the carbon permanently, creation of synthetic polymers like plastics and things similar in composition to oil might be the trick.

[GunnarSturla]

Yes, you could say burning of fossil fuels is a reversal of some sorts, but the earth has always stored some amount of carbon (with some of it released in volcanic eruptions). But the carbon we've re-introduced into the atmosphere had been sequestered for a long time (thousands or millions of years?) and for all intents and purposes wasn't a part of the cycle.

I guess we could create synthetic polymers and store them, but the scale of the problem is just so insanely massive. We'd need a place to store all that plastic (I don't even know where to begin to do the math, but we use around 10 gigatons of carbon each year [1] so it would take up some amount of space), and we'd also have to hope that bacteria won't develop that can digest it

[1] https://www.wri.org/insights/co2-emissions-climb-all-time-hi...

[betwixthewires]

Well no matter how it gets stored it has to go somewhere. And I would think the volume of some synthetic polymer would approximate the polymers it came from, so it wouldn't take much more space if any as the oil it came from. Maybe it could even be pumped back into the wells. If bacteria get at them, they were going to get at the oil anyway. And their process might be slow enough to not cause a disruption, so it might not be a big deal.

I wonder how fast the carbon was sequestered to produce oil in the natural process. We don't know how much oil there is in the ground, so we really can't tell how much faster we are releasing it than it was captured. I wonder if there's data on the effect on the biosphere from that process and some other way to gauge the speed and also total carbon that has been sequestered naturally to create oil and gas.

[mynegation]

Don’t know much about oil, but carbon in the coal was sequestered because plants got outside of water and evolved to have lignin about 50 million years before fungi and bacteria learned how to process dead plant mass. During that time (known as Carboniferous Period) burned and dead wood just turned into brown and black coal.

[betwixthewires]

That's interesting. So all that coal was made in 50 million years? Imagine if nothing had evolved to metabolize lignin, how much less biomass there would be by now, how much colder the earth would be. Just a little more dead, in a slow death spiral. Evolution is cool.