Re: Seaweed ecosystems may not mitigate CO2 emissions | ICES Journal of Marine Science | Oxford Academic

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Tom Goreau

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Feb 21, 2022, 1:14:17 PM2/21/22
to Peter Fiekowsky, H simmens, carbondiox...@googlegroups.com, healthy-planet-action-coalition, Nicholas Kee

I think they are right.

 

I grew seaweeds for years in Jamaica, and made many measurements of ecosystem net production in Jamaica and Panama.

 

The argument that seaweeds are large carbon sinks is based on several major misunderstandings.

 

First the fact that high biomass is produced in some ecosystems does not mean they have high net production at all, the net balance is usually very close to zero, for example Amazonian rain forests where around 80% of the CO2 emitted from soil is from root respiration, not decomposition (T. J. Goreau & W. Z. de Mello, 1985, Effects of deforestation on sources and sinks of atmospheric carbon dioxide, nitrous oxide, and methane from Central Amazonian soils and biota during the dry season: a preliminary study, PROC. WORKSHOP ON BIOGEOCHEMISTRY OF TROPICAL RAIN FORESTS: PROBLEMS FOR RESEARCH, D. Athie, T. E. Lovejoy, & P. de M. Oyens (Eds.), Centro de Energia Nuclear na Agricultura & World Wildlife Fund, Piricicaba, Sao Paulo, Brazil, p. 51-66).

 

Second there is a popular but fallacious misconception that most of our oxygen comes from phytoplankton, but in fact it is easy to show from both oxygen and CO2 gradients across the atmosphere-ocean interface that the ocean as a whole is a heterotrophic system that consumes more oxygen than it emits. That’s due to terrestrial carbon dumped into the ocean and rotting there. Every coastal habitat I measured was consuming oxygen, the only exception being right over very shallow seagrass beds in clear water and full sun.

 

Now if you could trap that algae biomass for long term products (say bioplastics) and prevent it being eaten or decomposed, that might be useful, but most algae biomass is very hard to harvest, each for its own perverse reason (kelp and sargassum are the exceptions that prove the rule), and algae are ripped by the waves into little shreds that bacteria and marine fungi, with digestive enzymes specifically evolved for decomposing algae biomass of each chemical type, make short work of.

 

Note that sea grass, salt marsh, and mangroves have very different net carbon balance than algae, there much of the net primary production is stored in the marine soil. 

 

Thomas J. F. Goreau, PhD
President, Global Coral Reef Alliance

Chief Scientist, Blue Regeneration SL
President, Biorock Technology Inc.

Technical Advisor, Blue Guardians Programme, SIDS DOCK

37 Pleasant Street, Cambridge, MA 02139

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http://www.crcpress.com/product/isbn/9781466595392

 

Innovative Methods of Marine Ecosystem Restoration

http://www.crcpress.com/product/isbn/9781466557734

 

No one can change the past, everybody can change the future

 

It’s much later than we think, especially if we don’t think

 

Those with their heads in the sand will see the light when global warming and sea level rise wash the beach away

 

Geotherapy: Regenerating ecosystem services to reverse climate change

 

 

 

From: <healthy-planet-...@googlegroups.com> on behalf of Peter Fiekowsky <pfi...@gmail.com>
Date: Monday, February 21, 2022 at 12:05 PM
To: H simmens <hsim...@gmail.com>
Cc: healthy-planet-action-coalition <healthy-planet-...@googlegroups.com>
Subject: Re: Seaweed ecosystems may not mitigate CO2 emissions | ICES Journal of Marine Science | Oxford Academic

 

They appear to ignore the main thing that the kelp programs must do, which is upwelling.

 

I'm not an expert, but I know the ocean system is complex. Obviously the experts working on methane think it can sequester very significant amounts of CO2. Since it is being done as a commercial venture, if all it does is restore fisheries and ocean health, it's a good thing. CO2 removal depends on careful optimization--and that is not something this article sought to do. 

They're saying that if done poorly, seaweed could might not mitigate CO2 emissions.

We probably knew that already.

Peter

 

On Mon, Feb 21, 2022 at 8:18 AM H simmens <hsim...@gmail.com> wrote:

This paper, published earlier this month appears to argue that seaweed ecosystems are likely to be more of a CO2 source than sink.

Are there significant flaws in this argument?

Herb


https://academic.oup.com/icesjms/advance-article/doi/10.1093/icesjms/fsac011/6525671


Herb Simmens
Author A Climate Vocabulary of the Future
@herbsimmens

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Peter Fiekowsky

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Feb 21, 2022, 1:49:30 PM2/21/22
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Tom-
It's great to have a true expert..perhaps the top expert here.

I understand that the theory of kelp (and sargassum) CDR is that the seaweed sunk sufficiently deep will have its carbon sequestered for a century or more.

Is that consistent with what you're saying?
I understood the article to say that the changes in ocean chemistry due to the kelp growth would decrease future ocean CDR capability roughly in equal measure with the carbon sunk.
Did I get that right?

Peter

Tom Goreau

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Feb 21, 2022, 1:56:51 PM2/21/22
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If they can get the biomass down to the bottom, even if it rots immediately, it will return to the surface as CO2 on an average of 1500 years later. Longest delay time is for the Atlantic. If it lands in an anoxic zone it will take a lot longer for it to decompose, adding another useful time lag.

 

I don’t understand the last point, don’t see where they said that? For sure there are uncertain long term trade-offs especially if ocean circulation changes, which it could, and often non-linearly.

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H simmens

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Feb 21, 2022, 2:43:31 PM2/21/22
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For what it is worth this is what one of the co-authors said earlier today on Twitter:

“The key message is that these systems have far more complexity than is often considered, and that any generalisations or definitive conclusions (in either direction) are premature and problematic.”


Herb Simmens
Author A Climate Vocabulary of the Future
@herbsimmens

On Feb 21, 2022, at 1:56 PM, Tom Goreau <gor...@globalcoral.org> wrote:



Renaud de RICHTER

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Feb 21, 2022, 3:30:25 PM2/21/22
to Aria Mckenna, H simmens, Tom Goreau, Peter Fiekowsky, Carbon Dioxide Removal, healthy-planet-action-coalition, Nicholas Kee, Brian von Herzen
I thought that the overall idea was:
  1. to copy what farmers do on land: pack forage in silage bales, using some biosourced plastic
  2. but with oceanic biomass (seaweed, sargassum, others...)
  3. adding some ballast (serpentine or olivine powder)
  4. making them sink deep enough > 1000m, in an anoxic zone
Isn't that the general idea?
image.pngimage.png


Le lun. 21 févr. 2022 à 20:58, Aria Mckenna <ar...@globalcoolingproductions.com> a écrit :
This is incredibly disheartening. Can't help but wonder what Brian Von Herzen might think of this? 

Warmest Thanks For Everything You Do,
🙏❤🌎🌾🐋💫

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Tom Goreau

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Feb 21, 2022, 3:50:23 PM2/21/22
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Not sure how many proponents of seaweed harvesting and processing really know what it is like to work underwater?

 

This is infinitely easier to do on a field that doesn’t move than on a pitching boat at sea where calm conditions are the exception.

 

In the 1960s Wheeler North at Caltech was designing barges to harvest and bale kelp near Santa Catalina island. Someplace I have the old papers, but it was never economic enough for investors. During the 1970s oil crisis I was involved in seaweed harvesting efforts to make methane, but it was never productive enough to be really attractive, especially when oil prices came down (due political manipulation of prices, for reasons that had nothing at all to do with real supply and demand, and failure of the polluters to pay externalized costs for cleaning up their mess).

Renaud de RICHTER

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Feb 21, 2022, 4:01:58 PM2/21/22
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Tom,
I fully agree with you.
But don't you think that if by 2040-2050 DAC finally reaches costs of $100 per ton CO2, without the sequestration, then the development of efficient technologies for seaweed harvesting and processing, at much lower costs per ton CO2-eq will be possible?
To remove and sequeter 10Gt CO2 per year, or even more, will represent a $trillion industry.
Today, systems to collect floating plastics on the ocean gyres have been developed. I don't know if they are already efficient.

Peter Fiekowsky

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Feb 21, 2022, 5:03:01 PM2/21/22
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Tom-
If you're interested in the topic, I'll introduce you to Brian von Herzen, who has implemented kelp growing and harvesting technology which survived a category 3 hurricane in the Philippines in December.
There's no need to be hypothetical here--it's running at pilot scale, with commercial scale planned in 2 years.

Peter

Tom Goreau

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Feb 21, 2022, 5:07:50 PM2/21/22
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Thanks, Peter, I’ve known Brian for years, eager to hear more about his results!

Wil Burns

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Feb 21, 2022, 5:09:12 PM2/21/22
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Amen. However, we have a number of startups in this context, some of whose proposals I just reviewed in the XPrize competition, that are already selling carbon credits, premised on really questionables MRVs. There’s a real danger of undermining the credibility of this approach in its early stages. I get the need to amass capital, but, concur with Gallagher, et al.

 

wil

 

 

 

 

 

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Tom Goreau

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Feb 21, 2022, 5:13:19 PM2/21/22
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It won’t be as easy as you hope!

 

With regard to the plastic harvesting there is much less to it than meets the eye.

 

Their devices pick up only what is big and floating on the surface.

 

Having dived through much garbage and sewage I can tell you the dirty truth, most of this crap is floating all through the water column and on the bottom, where the barge never sees them. Nice to do, but basically more cosmetic than effective.

Eelco Rohling

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Feb 21, 2022, 5:54:16 PM2/21/22
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All

Through this discussion, I cannot help wonder if people had considered the Carbon footprint of large-scale shipping. 
Sure, plastics get harvested/removed, and that’s a great thing, but it’s collected far out in the open ocean, with return transit times of at least 7-8 days in the Atlantic and twice that in the Pacific. 

There’s an environmental benefit from removing the plastics that may make this a sensible proposition.

But collecting kelp/seaweed, and then baling it, and then shipping it out to an anoxic zone (NB, just as a detail, most of those are not found a deep as >1000 m, but rather between the base of the photic layer and about 1000 m) - I struggle to see how this might be done CO2 neutrally, let alone negatively in a substantial manner. 

I’m not trying to kill the discussion - just to introduce here the vast scale of the ocean, and the need to have kelp/seagrass harvesting as close to the dumping site as possible if we want to avoid the high carbon cost of transport with such an approach. The ocean is small and easily traversed only on a map, I always tell my students. It pays to prepare by assuming unfavourable scenarios.

Cheers

Eelco
===

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(Ocean & Climate Change)
- 2012 Australian Laureate Fellow
- editor, Reviews of Geophysics
Research School of Earth Sciences
The Australian National University
Canberra, ACT 2601
Australia

Mobile: (+61) 434 667441
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Sev Clarke

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Feb 21, 2022, 6:25:57 PM2/21/22
to Professor Eelco Rohling, Renaud de RICHTER, Dr. Thomas Goreau, Aria Mckenna, H simmens, Peter Fiekowsky, Carbon Dioxide Removal, healthy-planet-action-coalition, Nicholas Kee, Brian von Herzen
Hi Eelco,

This may be a way around the problems you have elicited.
SeaweedHydrothermalTreatment.pptx
SeaweedReactor.pptx

Tom Goreau

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Feb 21, 2022, 6:36:26 PM2/21/22
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We want one!

 

What does it cost to build a HTC plant on land to process Sargassum into hydrothermal biochar?

 

We can look for funding through the Blue Climate Fund when it is set up.

 

Thomas J. F. Goreau, PhD
President, Global Coral Reef Alliance

Chief Scientist, Blue Regeneration SL
President, Biorock Technology Inc.

Technical Advisor, Blue Guardians Programme, SIDS DOCK

37 Pleasant Street, Cambridge, MA 02139

gor...@globalcoral.org
www.globalcoral.org
Skype: tomgoreau
Tel: (1) 617-864-4226 (leave message)

 

Books:

Geotherapy: Innovative Methods of Soil Fertility Restoration, Carbon Sequestration, and Reversing CO2 Increase

http://www.crcpress.com/product/isbn/9781466595392

 

Innovative Methods of Marine Ecosystem Restoration

http://www.crcpress.com/product/isbn/9781466557734

 

No one can change the past, everybody can change the future

 

It’s much later than we think, especially if we don’t think

 

Those with their heads in the sand will see the light when global warming and sea level rise wash the beach away

 

Geotherapy: Regenerating ecosystem services to reverse climate change

 

 

 

Your thoughts?

 

Regards,

Sev

William S. Clarke    BA, BSc, (Melb) MBA (Stanford)

T: +613 5426 1330                 M: 0431 488 506

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P: PO Box 16, Mt Macedon, VIC 3441, Australia

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On 22 Feb 2022, at 9:54 am, 'Eelco Rohling' via Carbon Dioxide Removal <CarbonDiox...@googlegroups.com> wrote:

 

All

 

Through this discussion, I cannot help wonder if people had considered the Carbon footprint of large-scale shipping. 

Sure, plastics get harvested/removed, and that’s a great thing, but it’s collected far out in the open ocean, with return transit times of at least 7-8 days in the Atlantic and twice that in the Pacific. 

 

There’s an environmental benefit from removing the plastics that may make this a sensible proposition.

 

But collecting kelp/seaweed, and then baling it, and then shipping it out to an anoxic zone (NB, just as a detail, most of those are not found a deep as >1000 m, but rather between the base of the photic layer and about 1000 m) - I struggle to see how this might be done CO2 neutrally, let alone negatively in a substantial manner. 

 

I’m not trying to kill the discussion - just to introduce here the vast scale of the ocean, and the need to have kelp/seagrass harvesting as close to the dumping site as possible if we want to avoid the high carbon cost of transport with such an approach. The ocean is small and easily traversed only on a map, I always tell my students. It pays to prepare by assuming unfavourable scenarios.

 

Cheers

 

Eelco

===

Prof. Eelco J. Rohling
(Ocean & Climate Change)
- 2012 Australian Laureate Fellow
- editor, Reviews of Geophysics
Research School of Earth Sciences
The Australian National University
Canberra, ACT 2601
Australia

Mobile: (+61) 434 667441
Tel. Office: (+61) 2 612 53857
e-mail: eelco....@anu.edu.au

<PastedGraphic-1.tiff>




personal WebURL: http://www.highstand.org/erohling/ejrhome.htm

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Anderson, Paul

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Feb 21, 2022, 8:29:48 PM2/21/22
to Eelco Rohling, Renaud de RICHTER, Tom Goreau, Aria Mckenna, H simmens, Peter Fiekowsky, Carbon Dioxide Removal, healthy-planet-action-coalition, Nicholas Kee, Brian von Herzen, Anderson, Paul

The discussion about seaweed is good.  Please comment about  an alternative way to handle the seaweed:

 

A.  Collection either near shore (for land-based processing) or on  a barge(s) in the  open water or near shorelines.

 

B.  Crushed / squeezed / dewatered physically.

 

C.  Drying with sun and also by heat from burning pyrolytic gases.

 

D.  Pyrolysis in a RoCC kiln that is simple and relatively inexpensive to be on the shore or on a barge.   RoCC kilns info at   www.woodgas.com/resources 

 

The crucial unknow is the time and methods need to bring the seaweed down to modest moisture content (such as 20% or less).    This “method” could relate to clearing up water hyacinth and other undesirable aquatic biomass.  (Could red tide be collected by straining?)   And could controlled ocean fertilization (maybe in the Sargasso Sea?) actively grow the seaweeds for timely collection and pyrolysis?  There is open space on oceans with plenty of sunlight so the biomass could be grown for the specific purpose of prompt pyrolysis.

 

Biochar is carbon negative while also producing a product that has some commercial value that is expected to increase over time.

 

Tom G’s great experience might have some insights about this.   Or is there some “fatal flaw” in the current thinking?   And maybe such a flaw could be resolved?

 

Paul

 

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         with pages 88 – 94 about solving the world crisis for clean cookstoves.

 

From: 'Eelco Rohling' via Carbon Dioxide Removal <CarbonDiox...@googlegroups.com>
Sent: Monday, February 21, 2022 4:54 PM
To: Renaud de RICHTER <renaud.d...@gmail.com>

Cc: Tom Goreau <gor...@globalcoral.org>; Aria Mckenna <ar...@globalcoolingproductions.com>; H simmens <hsim...@gmail.com>; Peter Fiekowsky <pfi...@gmail.com>; Carbon Dioxide Removal <carbondiox...@googlegroups.com>; healthy-planet-action-coalition <healthy-planet-...@googlegroups.com>; Nicholas Kee <keenic...@gmail.com>; Brian von Herzen <br...@climatefoundation.org>
Subject: Re: [CDR] Re: Seaweed ecosystems may not mitigate CO2 emissions | ICES Journal of Marine Science | Oxford Academic

 

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Sev Clarke

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Feb 21, 2022, 9:08:36 PM2/21/22
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Hi Thomas,

Before considering costs, it would be well to establish proof of concept. This might be done using little more than a benchtop pressure-temperature reactor, such as is made by the Parr Instrument Company, see https://www.parrinst.com. Wet carbonization would probably occur at a temperatures and/or pressures well below that of supercritical water. However, making use of the energetics of decavitating, monodisperse bubbles generated by Perlemax’s Desai-Zimmerman Fluidic Oscillators (DZFO) might reduce the severity of conditions required for the transformation. More details can be found under the heading Winwick Hydrothermal Carbonization (WHC) in 
WinwickPaperv104.pdf

Robert Höglund

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Feb 22, 2022, 10:14:51 AM2/22/22
to Carbon Dioxide Removal

What Running tide is doing is using kelp that grows on buoys that degrade and it all sinks into the deep ocean, measured with GPS. 
Has anyone understood if the argument about kelp possibly not being net negative applies to this solution?

Best regards

Robert Höglund
+46 8 559 25 515 

Tom Goreau

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Feb 23, 2022, 10:48:01 PM2/23/22
to Anderson, Paul, Eelco Rohling, Renaud de RICHTER, Aria Mckenna, H simmens, Peter Fiekowsky, Carbon Dioxide Removal, healthy-planet-action-coalition, Nicholas Kee, Brian von Herzen

The greatest seaweed biomass is where we dump our sewage, fertilizer, and manure into the coastal zone, so the greatest impacts are near shore before the phytoplankton can consume it, not out in the open ocean.

 

We and many groups are trying to turn this into fertilizer and biochar in Jamaica, Panama, Mexico, Puerto Rico, and other places, but limited by funding.

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