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Seaweed could be scrubbing more carbon from the atmosphere than expected (2017)

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11–20 of 166 posts

Re: Seaweed could be scrubbing more carbon from the atmosphere than expected (2017)

#11
post #6

Really interesting. Makes me think of Daisyworld and the Gaia Hypothesis. Daisyworld is a model Earth covered in black and white daisies, that either absorb or reflect light. In the model, black daisies need less light because they absorb more, increasing the Earth's heat absorption. White daisies absorb less so need more light, but also reflect more light back, increasing the surface albedo of the planet and lowerin…

We know that there are a number of homeostatic (self-regulating) processes that affect the proportion of CO2 in the atmosphere; if it wasn't homeostatic it would have drifted off to an extreme long ago. The key question is how well and how rapidly these mechanisms can respond to an increase in CO2 levels.

The homeostasis might work in a limited range under which the biological world evolved in the recent past. Exceeding that range could quickly turn to a runaway geological event of rapid climate change, a state transition in a complex and unpredictable system.

Take for example the great oxidation event happening 2.5 billion years ago. As oxygen excreting algae began to take over methane producing organisms, oxygen started to build up in the atmosphere - first slowly, as there were lots of stuff to oxidize, like methane and iron. Eventually, these naturals sinks were saturated and oxygen levels reached the critical toxic point for the other species, leading to a runaway die-off where more and more oxygen was released and methane - a strong green house gas - rapidly disappeared from the atmosphere. This shock was so massive it produced the 400 million year Huronian glaciation - a whole planet freeze unlike any since.

So I have full faith life on Earth will eventually restore the feedback loops and get the temperatures back in the sweet spot. I have less faith that this will happen soon, or that most species, humans included, can survive such a massive transition event.

Re: Seaweed could be scrubbing more carbon from the atmosphere than expected (2017)

#12
post #5
post #4

Can we bio-engineer seaweed which doesn't decompose and can't be eaten? Its not a joke - these were the circumstances of early Earth, before microbes evolved to digest lignin and cellulose. Trees would fall and not decompose, eventually being compressed into coal. https://www.nationalgeographic.com/science/phenomena/2016/01...

It would probably be dangerous to engineer an organism that doesn't break down. Imagine a living, growing plastic. Except not a Dr. Who villain.

Well presumably we could still collect, dry and burn what accumulates on the shore, and the rest would fall to the seabed. If the alternative is a hothouse Earth, with large sections of the planet rendered uninhabitable, geoengineering schemes like this are going to be necessary. We can start with iron fertilisation experiments - Australia has a lot of it, and is near oceans.

Re: Seaweed could be scrubbing more carbon from the atmosphere than expected (2017)

#13
post #5
post #4

Can we bio-engineer seaweed which doesn't decompose and can't be eaten? Its not a joke - these were the circumstances of early Earth, before microbes evolved to digest lignin and cellulose. Trees would fall and not decompose, eventually being compressed into coal. https://www.nationalgeographic.com/science/phenomena/2016/01...

It would probably be dangerous to engineer an organism that doesn't break down. Imagine a living, growing plastic. Except not a Dr. Who villain.

This classic novel explores that scenario.

https://www.goodreads.com/book/show/41094.Greener_Than_You_T...

Re: Seaweed could be scrubbing more carbon from the atmosphere than expected (2017)

#14

At least one good news Maybe we should look into farming seaweed (and other algae)

From the article:

> All in all, super-powered seaweeds could sequester around 173 million metric tons (190 million tons) of carbon each year, about as much as the annual emissions of the state of New York.

It's not that much in comparison to the emissions of the entire industrialized world.

Every bit helps of course, but it's not a magical solution to our problems.

Re: Seaweed could be scrubbing more carbon from the atmosphere than expected (2017)

#15
post #5

Earlier quoted context omitted.

It would probably be dangerous to engineer an organism that doesn't break down. Imagine a living, growing plastic. Except not a Dr. Who villain.

Well presumably we could still collect, dry and burn what accumulates on the shore, and the rest would fall to the seabed. If the alternative is a hothouse Earth, with large sections of the planet rendered uninhabitable, geoengineering schemes like this are going to be necessary. We can start with iron fertilisation experiments - Australia has a lot of it, and is near oceans.

You risk creating a locust-like scenario, where it's impossible to fully control areas with specimen outbreaks.

Re: Seaweed could be scrubbing more carbon from the atmosphere than expected (2017)

#16
post #5

Earlier quoted context omitted.

It would probably be dangerous to engineer an organism that doesn't break down. Imagine a living, growing plastic. Except not a Dr. Who villain.

Well presumably we could still collect, dry and burn what accumulates on the shore, and the rest would fall to the seabed. If the alternative is a hothouse Earth, with large sections of the planet rendered uninhabitable, geoengineering schemes like this are going to be necessary. We can start with iron fertilisation experiments - Australia has a lot of it, and is near oceans.

Wouldn’t burning it defeat the carbon sequestration purpose?

Re: Seaweed could be scrubbing more carbon from the atmosphere than expected (2017)

#17

At least one good news Maybe we should look into farming seaweed (and other algae)

They've been farming seaweed in places like Japan since the 1600's/1700's and is a $2 billion industry. They also farm it all through south-east asia :)

Being done in Australia: http://www.abc.net.au/news/2018-02-16/king-island-kelpers-ke...

Looking at opening more in Australia: http://www.abc.net.au/news/2017-08-30/not-just-for-sushi-the...

Re: Seaweed could be scrubbing more carbon from the atmosphere than expected (2017)

#18
Stupid question incoming. Does it really help us to trap even more CO2 under the surface? If something exposes that CO2 again, it will be back up in the atmosphere right? So it feels like this would be a "solution" like storing used uranium underground in lead containers - eventually it will become a problem. Or am I completely wrong here?

Re: Seaweed could be scrubbing more carbon from the atmosphere than expected (2017)

#19

Stupid question incoming. Does it really help us to trap even more CO2 under the surface? If something exposes that CO2 again, it will be back up in the atmosphere right? So it feels like this would be a "solution" like storing used uranium underground in lead containers - eventually it will become a problem. Or am I completely wrong here?

Your question isn't stupid.

Right now though, we are storing our CO2 in the atmosphere. This causes problems. To solve those problems, we need to store the CO2 somewhere else.

It can be released again, but lets hope that the massive effort required to yank the CO2 out of our atmosphere causes the sunk cost fallacy to kick in until we've completely moved past fossile fuels.

Re: Seaweed could be scrubbing more carbon from the atmosphere than expected (2017)

#20

Earlier quoted context omitted.

Well presumably we could still collect, dry and burn what accumulates on the shore, and the rest would fall to the seabed. If the alternative is a hothouse Earth, with large sections of the planet rendered uninhabitable, geoengineering schemes like this are going to be necessary. We can start with iron fertilisation experiments - Australia has a lot of it, and is near oceans.

Wouldn’t burning it defeat the carbon sequestration purpose?

That would be a desperate attempt to reverse a runaway process, if it turns out to be too successful.
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