Seaweed Patches To Help Slow Climate Change

A little over a year ago I read a news article about the possible use of seaweed of some kind to help reduce the amount of carbon in the atmosphere and store it in the seabed. The plan was to eventually make a 50 or 100 mile wide floating ring to hold all the plants together and anchor it to the sea floor. I can’t remember the exact article or the details of it, and was wondering what other people think about the possibility, or if anyone has updates on it. It seemed like an interesting idea to me, but I don’t know much about that kind of thing.

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usually when people try to make big changes like this, they make things worse.

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Yeah, plenty of things similar have gone wrong, I just wasn’t sure if this had actually happened yet regardless of if it should or not.

here’s a recent article describing different efforts and issues: to me, these all sound like perpetual “a decade from now” projects more likely to mess things up even more than to actually fix anything.

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It certainly does sound like a more long-term solution that would have some problems.

well, surely a smaller test would reveal whether or not this could help. experimentation is part of the scientific process.

unless, of course, the entire endeavour is a money grab or scam to get attention…

Seaweed is a fertilizer. There is a product called Seaweed extracts. It contains the micronutrients of the ocean. Sometimes I feel seaweed extracts can make plants grow better. At some concentrations, it makes plants flower instead of grow vegetatively. Sinking it into the ocean is not a sound idea as it is bound to get eaten by other creatures in the ocean or it may be wash up at the beach. The carbon is not locked up long term in that case. If you use seaweed to add into coastal soil, perhaps the plants can take up the carbon or nutrients and store it. but seaweed contains sodium. Plants do not like sodium that much.The potassium and micronutrients are good.

hmmm… sure, i suppose folks did raise billions of dollars and attempted to build a small hyperloop, and they found out that they just wasted a bunch of money and should have just built a train if they really wanted to move a bunch of people instead of trying to move people around in capsules in a low pressure tube.

with the seaweed, they are talking about moving nutrient-rich water up from the deep ocean to feed the seaweed at the surface and then moving all that seaweed to sink in places that are oxygen poor so that the seaweed doesn’t just get converted back into the environment. i guess folks can raise billions of dollars to test this out, and we’ll see what happens.

I think most of the schemes to photosynthesise our way out of global warming don’t think sufficiently long term. The carbon locked up by plants then has to stay locked up for centuries. As mentioned above, seaweed will just get eaten and the carbon be returned to the ecosystem as carbon dioxide or methane. Perhaps they thought the gases would stay dissolved in the sea. But levels of carbon dioxide in the sea are already rising and the acidification is having its own impacts on marine life so I don’t think making the sea more acidic is a good solution. If the seaweed was used in a way that replaced fossil fuels, that could be helpful but not so long as there remains demand for all the fossil fuels that are extracted. It has to result in less fossil fuel being burned in order to have an effect on atmospheric greenhouse gases.,


lol okay decent point. I guess that theoretical models are important too. but tbh the fever dreams of one man with too much money are, I hope, an outlier.

I do wonder whether this has been tested, say, in a brackish lake or a bay or some place. Even in an indoors controlled model.

in any case, it’s much more financially effective to prevent carbon emissions than to lock up existing carbon.

cross out financially, and this is exactly right.

well, naturally it’s also the responsible thing to do. But in a literal sense, in terms of dollar cost per ton CO2 removed from the atmosphere, “financially” is still true – and becomes increasingly relevant as you scale up:

like it or not, conservation, studies, law creation and enforcement, construction etc costs money… and in a world dominated by capitalism, we are bound to that sad reality.

Sure, there is much innovation and other beneficial economic activity generated by individuals and businesses, large and small, acting in their own self interest. However, there are also many situations in which action for self interest works counter to the general good. For that reason, governments and organizations must get involved to steer incentives and regulation in a direction that incentivizes action in favor of the general benefit. Without carefully designed effective governmental and organizational intervention, the contribution of the use of inexpensive fossil fuels to climate change will likely continue as a significant source of harm.

There have been several seaweed-based startups in my area. I understand that they are currently mostly indigenous efforts but that may change. Currently, the emphasis is on food and feed rather than long-term carbon sequestration.

Here are a couple of links you might want to read to counter the doomer narrative - Economic and biophysical limits to seaweed farming for climate change mitigation and How feeding cows seaweed could help P.E.I. meet emission targets and boost this business


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