Discussion of National Academies Study

We have gathered that the National Academies of Science study on carbon dioxide removal is probably one of the most influential research docs in this space right now.

What would you say the strengths and weaknesses of that study are?

Additionally, what are the other key reports in the CDR space you would recommend and why?

Share any links, research documents, visualizations, or other resources that you have seen!

I believe a major weakness of the NAS report was not focusing on oceans. What do you all think?

I’m not quite finished with the NAS report, but was struck by the chapter on mineralization and the potential of in situ mineralization in ultramafic rocks. Any recommendations where I can continue to read more about this mechanism and ongoing work in it? Any thoughts on its potential or feasibility?

hi, this is Peter Kelemen, responding to posts by cnatan and jamesburbridge. I was the lead author on Chapter 6. I have a Google Scholar page where you can see a relatively up-to-date list of my papers on carbon mineralization and other topics. It would also be good to search for papers by Greg Dipple and his colleagues, papers by Phil Renforth and his colleagues, and papers on the CarbFix Experiment in Iceland. And there is A LOT of other good research on this topic. As a general thing, Chapter 6 is a relatively comprehensive review as of summer 2018, and the list of references could be useful. With regard to the lack of focus on the oceans in the NAS report, I agree with cnatan that this was a significant omission. On this topic, I recommend the review paper by Renforth & Henderson in Reviews of Geophysics, 2017, as a good starting point for understanding the idea of increasing ocean alkalinity, which also has generated a pretty large number of good papers. I am not very familiar with more biologically-oriented ideas about CDR in the oceans.

Hi @peterk and thank you for the feedback! Greg Dipple had been mentioned by some colleagues as an expert we should reach out to, so we’re working on that. Re: the NAS report, I’ll be sure to check out the references to continue our deep dive.

While I’ve got you here, some of these mineralization/advanced weathering systems sound very compelling, but an engineered solution remained “speculative,” if I remember the wording correctly. Is that still the case or are people pursuing major demonstrations of in-situ combined capture and storage?

Yes, there are some very positive, recent developments, with funding for scoping field sites for pilot experiments, and some potential investors. In this regard, we are farther along in this than ever, but … I’ve been almost as optimistic before … so we’ll see.

With regard to “speculative”, that depends what you mean. There are plenty of good geological data. For instance, I would emphasize that natural peridotite systems sometimes achieve 100% carbonation, in which every single Mg and Ca atom gets together with CO2 to make carbonate minerals. And, there are other good data that demonstrate that individual, natural systems continue to consume dissolved CO2 in ground water, reacting with peridotite to form solid carbonates, for tens to hundreds of thousands of years, without clogging up or running out of solid reactants. And the lab kinetics data consistently indicate that carbon mineralization is fast when one of several abundant, rock forming minerals are present. All this said, there is no proof of concept at the scale of a pilot experiment like CarbFix, and in particular the issue of “clogging” vs “cracking” remains a possible show-stopper.

re 3/21 post by cnantan.

Indeed the NAS study mentions but does not elaborate at length on ocean storage options, and in particular those that could emphasize carbon mineralization. I’m not certain this is the point of your question or not, but if so, I might call your attention to previous work on feasibility and capability of sub-ocean storage options in basaltic lavas. No at-sea demonstrations have yet been conducted, however there is significant potential for scale-up and benefit in these environments, both via industrial and direct air capture solutions. Some background references include:

Goldberg, D., and A. L. Slagle. 2009. A global assessment of deep-sea basalt sites for carbon sequestration. Energy Procedia 1(1):3675-3682. DOI: https://org/10.1016/j.egypro.2009.02.165.

Goldberg, D. S., T. Takahashi, and A. L. Slagle. 2008. Carbon dioxide sequestration in deep-sea basalt. Proceedings of the National Academy of Sciences of the United States of America 105(29):9920-9925. DOI: 10.1073/pnas.0804397105.

Goldberg, D. S., D. V. Kent, and P. E. Olsen. 2010. Potential on-shore and o -shore reservoirs for CO2 sequestration in Central Atlantic magmatic province basalts. Proceedings of the National Academy of Sciences of the United States of America 107(4):1327-1332. DOI: 10.1073/pnas.0913721107.

Goldberg, D., K. Lackner, P. Han, A. Slagle, and T. Wang, 2013, Co-location of air capture, sub-ocean CO2 sequestration, and energy production on the Kerguelen plateau, Environ. Sci. & Technol., 47(13), 7521-7529, doi:10.1021/es401531y.

Goldberg, D. and K. Lackner, 2015, Creating negative emissions at remote CO2 sequestration sites, Greenhouse Gases: Sci. & Technol., 5:1–3, doi: 10.1002/ghg.1489, available online at: http://onlinelibrary.wiley.com/journal/10.1002/(ISSN)2152-3878/earlyview.

Snæbjörnsdóttir, S.Ó., F. Wiese, T. Fridriksson, H. Ármannsson, G.M. Einarsson, and S.R. Gislason. “CO2 storage potential of basaltic rocks
in Iceland and the oceanic ridges” Energy Procedia 63 (2014): 4585–4600.

Gutknecht, V., S.Ó., Snæbjörnsdóttir, B. Sigfússon, E. S. Aradóttir, and L. Charles. Creating a carbon dioxide removal solution by combining rapid
mineralization of CO2 with direct air capture"
Energy Procedia 146 (2018): 129-134.

Thank you so much @dgoldber for the background references. The topic of deep-sea basalt sites for carbon sequestration is a fascinating one. What do you think is the C02 removal and economic potential of this CDR technique please?

the storage capacities of offshore basalt are estimated to be enormous (>100,000 Gtons CO2 worldwide) and offer permanent storage potential through mineralization. For CDR, this concept marries offshore basalt storage with DAC technology and renewable energy sources – only limited by the development of each these technologies in becoming efficient and economical, plus a real valuation on C removal from the atmosphere.

Hi @dgoldber , thanks for your response! Are you aware of any efforts to commercialize the basaltic lavas (as building materials or others)? In other words, is there a path to economic viability for this outside of a real vauation on C removal from the atmosphere?

Does dead seaweed sink and is its carbon then sequestered in the ocean depths?

Sargassum blooms are causing huge problems on beaches around the Caribbean in particular. If it can be sunk efficiently to prevent it from reaching the beaches, the tourism industry could help pay the costs of doing it. The Cancún-Puerto Morelos hotels association has estimated that cleaning their beaches of sargassum will cost at least 700 million pesos (US $36.7 million) this year. One estimate says a million tons of sargassum can be expected on Mexicos beaches this year. Even the Mexican Navy will be fighting the problem.

Imagine autonomous solar/wind-powered ocean-going harvesters (hundreds of them?) that seek out, take on, and possibly shred sargassum to pop the air sacks that keep it afloat, or expose it to high-level UV light to kill it, or otherwise treat it and return it to the sea to sink.

Perhaps such equipment could be stationary, positioned strategically in ocean currents that bring the sargassum to them for processing.

Thank you @SteveK8! If you have a moment, we have several new threads here we would also love your input on! @DanSelz @jamesburbridge Any thoughts here on the potential of oceans and carbon?