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Comment by betwixthewires | Hacker News Reader

I've got a question, maybe a stupid one to those in the know, but why not just trap carbon in biomass?

If we trap it in biomass, it will escape if anything happens to the ecosystem storing the carbon (like a forest fire).

The fundamental problem is that the earth was in a balance, with regards to carbon; a bunch was trapped in biomass, and cycled through the carbon cycle [1]. Then humanity did two things; we destroyed a lot of carbon stores (with agriculture, deforestation and setting off soil erosion), and (more importantly) dug up and released even more carbon into the carbon cycle. It will not be enough for us to only trap it in biomass, we need to permanently remove it from the cycle.

We definitely need to do both, and storing carbon in biomass is probably more cost-effective currently, but if we're going to restore the balance, we'll need more than biomass.

[1] https://en.wikipedia.org/wiki/Carbon_cycle

"The fundamental problem is that the earth was in a balance,"

Nit pick but, is there anything that says the earth isn't or won't be at a balance?

Sure, climate change will be hugely impactful, especially for humans, but I figure the earth will still be in balance, just not the one we are used to.

Historically huge swings in climate did occur, they also often coincided with catastrophic extinction events. Forgive me for not caring that the warmer Earth is newly “in balance” for whatever heat-loving species emerge.

Venus and Mars both found their own kinds of balance. As far as we can tell, balances that favor life are rare.

I'm not arguing the point you're arguing against, but I felt the need to point out that those two extremes are not what we are talking about, we are talking about a new "balance" that is known to have supported life in the past.

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.

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...

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.

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.

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.

Climeworks addressed that question here:

https://www.facebook.com/climeworks/posts/we-often-receive-q...

The short version is: We should be doing all the things. Growing trees is cost-effective but requires a lot of land and water, which we don't have infinite supplies of.

In the trend of questions we kinda know are dumb questions, why not just capture it where it comes out, at the powerplants?

We should do that too, but then the question becomes what to do with the carbon. It turns out that getting rid of it in a safe way is a pretty difficult problem. The solution that's described in the article needs a lot of freshwater and the right type of rock for it to flow through so it can't be done where most of the power plants are located.

That leaves basically two solutions; capture the carbon from the air, which takes a lot of energy, or ship it with tankers. The first is being done (at a small scale) and the second is being worked on.

In an ideal world, we wouldn't have power plants that release carbon, but that's another discussion :)

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