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Comment by KorematsuFredt | Hacker News Reader

Why are people not considering just growing large trees to capture carbon cut down those trees and just coat them in plastic and throw them at the bottom of ocean/desert or some kind of storage where this carbon can stay trapped for thousands of years ? What am I missing ?

I think growing trees is better than just capturing CO2 directly as growing a large forest might have other advantages and a lot of wood can be used for normal human industry as well.

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Because 20 million trees planted would offset US emissions by 2 days.

https://www.youtube.com/watch?v=gqht2bIQXIY

But I can’t tell if 20 million trees is a lot or a little.

The amount of effort required for 10 million trees a day would require everyone in the US to plant a tree each month. This would likely also require people to care for enough saplings to plant a new tree each month.

It's not an insurmountable level of effort per person, but if you try to do it on a large scale you inevitably end up with logistical problems, and it would require quite a lot of space.

I am not sure I understand your math here. Let’s say every adult in the US, 300M, plants a tree each month for 12 months, 3.6B trees planted in a year. Or are you factoring in saplings that fail to grow or something? Is it that bad that for every 160 trees planted only one survives?

Edit: strike that I see what you meant there with the a day. I just should have actually read what you wrote before I commented.

US adult population is around 200 million.

Also, they can't even get people to wear a mask or take a shot. Getting all these people to plant trees seems like an insurmountable task.

I did some quick googling and the first figure I found was that Americans plant around 1.6 billion trees every year. That is around 4.4 million every day, almost half of what is required for the carbon offset claims by GP.

Actually 20 million trees every 2 days doesn’t sound that ridiculous. Especially as we build more green infrastructure and reduce the daily emissions.

https://www.greenandgrowing.org/how-many-trees-are-planted-e...

I wonder if there's any legs in algae or seaweed. Wouldn't take up valuable land to grow and is fast growing.

Seaweed is great - it also pulls excess nitrogen out of the water, can be co-cropped with bivalves, can be fed to cows for decreased methane production, can be eaten directly in many forms…

If we had an actual price on carbon seaweed production would be a boom industry.

Couldn't you use it in large tanks to suck out CO² directly from the air? What makes this more expensive than currently proposed alternatives? Even if you don't use the seaweed in the end, you could just dry and bury it I guess?

EDIT: After some research I found an interesting article addressing this: https://www.technologyreview.com/2021/09/19/1035889/kelp-car...

That is an interesting link, thanks.

I'll never understand why it's always "stop climate change" or "deny climate change" but there's essentially no room for "fix climate change" or "reverse climate change". The resources are allocated for polarization and not pragmatism.

Carbon capture using trees is very common. Most carbin offset programs fund this.

No need to drop it to the bottom of the ocean though. Just build something out of it.

https://www.terraformation.com/blog/trees-are-a-faster-solut...

Maybe because trees contain a lot of water/nutrients? Tbh I've always wondered what you've said too, though I'd just dump the wood in old mines etc.

I found this https://cbmjournal.biomedcentral.com/articles/10.1186/1750-0...

Or build houses and bridges and stuff with them instead of concrete.

The US can’t keep up with infrastructure maintenance as it is, let alone moving to materials with shorter lifespans and more maintenance

I don't think that the economy of wood is worse in the long run. It is quite much faster and cheaper to build with, and as long as it isn't allowed to be wet for long periods of time it also lasts indefinitely (there are wooden temples that are 1300 years old), and repairs are usually faster and easier than similar in concrete.

I'm not sure that's a good data point considering there is stone/masonry structures that old or older. Is there evidence that wood infrastructure is cheaper/more durable from a lifecycle perspective? The industry estimate for timber bridges is typically 20 years (although they may be treated to extend the life further) while 75 years or more for steel or concrete bridges. Timber/glulam also tends to deteriorate faster.

"At comparable ages and spans, smaller percentages of prestressed concrete bridges are classified "structurally deficient" than steel or timber bridges."[1]

[1]https://trid.trb.org/view/369244

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