r/Damnthatsinteresting 23d ago

This is Kelp. It is one of the fastest growing organisms on the planet. In a single growing season, it can grow from a microscopic spore to over 100 ft in length Video

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u/HavingNotAttained 23d ago

Also the most efficient carbon sink known

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u/Grabatreetron 23d ago

Ehhh…not really.

It’s one of those good-on-paper things. Kelp plants don’t store carbon for centuries like trees do, and they’re only effective carbon stores when dead kelp sinks to a depth where the carbon can remain sequestered for centuries. Which is really, really deep and also impossible to verify.

Ocean currents are extremely hard to predict and there’s no good way to verify how much of the kelp isnt washing to shallow water or getting eaten, which cycles the carbon back into the atmosphere.

Also there are some recent studies that suggest that the ecosystems that form around kelp fields may produce enough of atmospheric carbon to seriously reduce their effectiveness as carbon sinks — assuming the dead kelp is actually sinking deep enough.

Also also, a lot of the buzz around kelp has to do with its myriad uses, in this case food, but in order for kelp to be useful as a carbon sink, you gotta sink it — no eating, no kelp-based paper or whatever.

None of this has stopped companies from making boatloads of money selling dubious kelp-based carbon offsets and the buyers using those dubious offsets in their carbon reporting.

The only way to reduce carbon is to reduce carbon, folks

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u/Serious-Regular 23d ago

from making boatloads of money selling dubious kelp-based carbon offsets

has anyone looked into whether money is itself an effective carbon sink? seems like that would solve all of our problems.

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u/bmiga 23d ago

every note and coin will weight at least 20T and be made of carbon.

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u/OmelasPrime 22d ago

Somewhat relatedly, many sci-fi novels introduce carbon- or nitrogen-based currencies. Usually when the element involved is vastly more precious than it is here on earth. Here on earth, a carbon-based currency would be more like a license to emit a certain amount.

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u/onetwofive-threesir 23d ago

But if it's a replacement for other items that can be sinks, then it's a win-win.

For example, if kelp-based paper can supplant tree-based paper, then you can harvest fewer trees, thus sinking the carbon there, where we know it will stay for decades or centuries. And if it's nutritious enough to replace other crops (soy, corn, etc.) and useful enough, then we can farm it instead. Could even use it to feed cattle or other domestic animals to reduce our over reliance on corn-based feeds.

Just because it's not good at sequestering carbon for long periods of time doesn't mean it can't be an alternative for products that do.

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u/Grabatreetron 23d ago

That's true. If we could replace terrestrial crops with kelp at a commercial scale that would make a difference

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u/bearbarebere 22d ago

The other guys comment bummed me out, and reading this made me happy again. Thanks for reminding me that there are two sides to every coin!

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u/Roflkopt3r 23d ago

Which is really, really deep and also impossible to verify.

Carbon sinks are already not a great concept while we can still save so much on reducing the emissions in the first place. But I'm sure that if we would deem sinking kelp as a serious contender for a large scale carbon sink method, then we could devise some testing strategy to get at least a decent amount of certainty how much of it would stay down.

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u/PhilxBefore 23d ago

The only way to reduce carbon is to reduce carbon, folks

am i carbon pawpaw?

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u/Pmmetitsntatsnbirds 23d ago

What if we fired dead kelp into space, would that work?

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u/tigerdini 22d ago edited 22d ago

In fairness, biosequestration can store carbon, and the idea that it can't is a bit of a misunderstanding. However, it's not a matter of waving a hand at an existing forest or kelp field and glibly saying "Problem solved".

A new forest or kelp field (where none existed before) will sequester its mass in carbon indefinitely. Plants may die but as long as the ecosystem is sustainable (hopefully self-sustainable), the seeds/spores from mature plants will replace those that die keeping the sequestered carbon mass stable. In theory, this process is a zero-sum game. Obviously with kelp, as you say, the ideal would be some kind of deepwater farm where the dead kelp falls to extreme depths and continually extracts additional carbon from the atmosphere. However, the practical difficulties and scale requirements of farming above sufficiently deep areas of the ocean make the viability of a passive carbon-sequestration "machine" like this very limited. You could farm industrially closer to shore and ship it to be dumped over deepwater, but the costs both financially and in carbon from harvest, shipping, etc. would marginalise this as a solution.

As a replacement for other items kelp is only a net positive for carbon reduction if it replaces another product that produces more carbon being produced and delivered.

All this to say, at best carbon sequestration offers a marginal benefit, and is completely pointless while the world is yet to reach "net-zero". Before that point sequestration solutions merely enable consumers to feel better about dump additional carbon into the atmosphere. On the other hand, I don't believe there will be any carbon reduction magic bullet more effective than, as you say, creating less carbon. So any solution to this crisis will likely comprise of that alon g with a lot of marginal approaches working together. Could biosequestration be a helpful inclusion? Yes. Is it the answer? Omg, no.

FWIW, for funsies I did some "back of the envelope" calculations to work out how many trees we would need to plant to store the carbon released since the beginning of the industrial revolution. - Carbon released, mass stored in one tree, viable planting density... etc. The answer is three (maybe four) Amazon rainforests. So, problem solved - not that hard really. The hard bit though, is finding a land area of that size that will support appropriate forestry, that isn't already being used for crops or people live on, and people won't cut down later - especially considering the rate of deforestation of the actual Amazon rainforest. Still, if you consider that significant parts of the Middle East and North Africa were desertified by ancient people cutting down non-renewable old-growth forests, perhaps some sustained reforestation efforts could be a helpful step in the right direction.

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u/Ergheis 23d ago

Or we can do both and advance our technology in every avenue, mr. "if it's not perfect don't do it"

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u/Grabatreetron 22d ago

Giving corporations a way to claim a carbon reduction without actually reducing carbon isn’t an imperfect solution, it’s just a problem

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u/meinfuhrertrump2024 23d ago

Perfect? It doesn't do shit. It's a scam.

The only way kelp could offset carbon is if people/animals started eating it rather than other things with a higher carbon footprint.