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Comment by knodi123 | Hacker News Reader

I wonder if there's any possibilities in engineering a quick-growing trash tree that would have a higher percentage of mineralization, or properties that facilitate quick pseudo-petrification, so that it can be embedded in concrete without worrying about rot. They would serve the same purpose as rebar, but with greater volume meaning less concrete needed. And it would be a near-permanent carbon sink.

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Yes, it's called bamboo and it sequesters 3x the carbon and grows to maturity 10x faster than a normal forest (3 years vs 30 years). And bamboo has some of the qualities of rebar, so should mix nicely with concrete. Of course it is best grown in tropical regions, hence why most of the talk here is about trees.

Bamboo is also incredibly invasive which is great for self propitiating the carbon solution, but terrible if we ruin all of our eco systems for

Some of the 10,000 species have this property, but by no means is it the defining characteristic.

The massive scale of growing bamboo plants that would be needed would best take place in large empty deserts. Finding the right species and water supply should be the main challenge with this concept.

Living Carbon is doing something similar, working on quick-growing trees that take up enough metals from the soil to slow decomposition.

That seems much more complicated than just planting some fast growing plant (eg. bamboo), converting it to charcoal, and burying it somewhere. That achieves the same carbon sequestration effect, without having to worry about petrification.

This is exactly what I was thinking. Bamboo has to be one of the fastest growing therefore carbon sucking plants, right?

Switchgrass is faster, and grows in more climates.

It certainly is more complicated. The difference is that

1.) it attacks three different problem sources - the carbon already in the air, and the carbon generated by concrete production, and the carbon from steel production. Cement is responsible for about 8% of global CO2 emissions [1], and steel another 8% [2].

2.) it offers profit incentives, since the people using the trees get a direct benefit (unlike people throwing biochar into an ocean trench). Any long-lasting solution to our carbon problem is going to have to find a way to exist on something other than direct carbon-dedicated subsidies. A self-sufficient business can survive shifting political winds much better than a literal money-sink.

[1] https://www.bbc.com/news/science-environment-46455844

[2] https://www.mckinsey.com/industries/metals-and-mining/our-in...

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