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Comment by d_theorist | Hacker News Reader

I don't understand why more isn't done to implement large-scale carbon capture and storage technologies. There are quite well-understood and proven technologies to do this, but they don't seem to be on anybody's agenda.

Trying to bring down CO2 concentration by convincing people to give up cars, food and planes is obviously a losing strategy.

If we're serious about preventing climate change we're going to have to actively remove carbon from the atmosphere. But nobody seems interested.

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Well, it's not really a problem now. Spring came a month early, but who cares? Islands aren't underwater yet, there's plenty of food in first world countries (who would be paying for this) and there's no serious drought. From a politician's point of view, you're proposing to spend billions or trillions to solve a problem that we're still only seeing hints of (with an extremely first-world centric view, of course).

If the technology works, why not wait until the people demand it, instead of telling them they have to feel the pain of paying for it now to solve a problem no one can see?

My understanding was that they were expensive and without a price on carbon, no one has an incentive to do it.

You don't actually even need to get it out of the atmosphere, you can retrofit power plants with carbon capture tech that is more efficient, but still, there is no incentive.

The best incentive is to come up with something of value that can be done with that carbon. Then it becomes "money I could grab" instead of "pollution I should not be releasing".

I mean, the main thing we've figured out to do with carbon is set it on fire to create electricity, which is sort of what got us into this mess ;)

But even if there was a better use for carbon, it would still have to be cost competitive with digging it out of the ground, which it's not.

Aren't trees the ultimate carbon-capture devices? They are solar powered, turn co2 into building materials, and require very little maintenance.

Not really. There's something called the "Forest Carbon Cycle". Forests do not statically capture carbon long term. They are constantly taking carbon in but also releasing it through the death of trees and through the soil. Trees can temporarily capture carbon, but ultimately it will be released again unless they are burned.

They also take up a lot of space.

[EDIT] I should probably clarify that I have nothing against trees, and they definitely can help with sequestration, and they have lots nice properties. I was mainly reacting against "the ultimate carbon-capture devices", which they really are not.

I would love to see engineered wood, like Cross-laminated timber, replace concrete as a structural building material.

Why? And laminates are typically petro products.

https://en.wikipedia.org/wiki/Cross_laminated_timber

There's some glue involved, but it removes the carbon stored in the wood from the normal carbon cycle of trees and it would also displace cement/concrete, whose production emits loads of carbon dioxide.

I've been thinking about economical carbon sequestration uses for the heliostat molten salt reactors. Desalinate sea water (sell fresh water) -> power a generator with steam (sell excess energy) -> grow trees in the desert (sell the trees to a mill) -> go back to start.

> Unless they are burned

Won't burning the tress will change the stored carbon in the tree to carbon dioxide?

He's probably referring to biochar. Turning biomass into charcoal, grinding it into powder, and working it into soil is known to sequester carbon for at least a thousand years.

Exactly.

Trees would be great. Right now we're deforesting at massive scale. So first we have to stop doing that, then maybe we can reforest and pull down some carbon, and preserve some biodiversity while we're at it. We probably have to get this done soon, because drought, heat stress, disease, and forest fires are starting to turn some forests into net carbon emitters.

But there are also technologies in development that can remove about a thousand times as much CO2 from the air as trees, for a given land area.

> But there are also technologies in development that can remove about a thousand times as much CO2 from the air as trees, for a given land area.

Could you be more specific?

Are they reasonable to deploy on the scale we actually need?

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