I have just had a piece published in the Bulletin of the Atomic Scientists: ‘We’d have to finish one new facility every working day for the next 70 years’—Why carbon capture is no panacea . I’m not allowed to repost the whole article here, but it is open access on the Bulletin website.
I looked again at the outsized role that carbon capture and storage (CCS) along with Bioenergy Carbon Capture and Storage (BECCS) play in most of the IPCC 2 degree models. I have argued previously that the gigantic quantities of CO2 that need to be sequestered in geological reservoirs, according to these models, face huge obstacles in terms of scalability, financing, technical hurdles and public acceptance.
A recent paper in Science reported on a breakthrough experiment in Iceland in which CO2 (from a volcanic source) dissolved in water was injected into basalts at depths of 400-1000 metres. Using isotopic and chemical tracers, the researchers estimate that the CO2 had been mineralized into benign and stable carbonate minerals in the space of just two years. This was faster than suspected and, if this process turns out to be scalable, then sequestration in basalts would provide a solution to the need to monitor conventional sedimentary rock disposal sites for leakage over the long term.
Unsurprisingly, the “if” in “if this process turns out to be scalable” is a big one. For one thing, the Icelandic process requires a lot of water. I estimated, just as an example, that if the current emissions from the US were sequestered in the Columbia River Basalt Group, it would require half of the annual flow of the mighty Columbia River itself. Of course, nobody is proposing sequestration on such a scale in one region, it’s just an illustration of the scale of water required form the river and the scale of fluid injection required into the basalts.
Anyway, please read the article, if you are interested.
Below, I have included some footnotes and references that I had included with my original draft, but that were not included in the final Bulletin version. Note that subsequent edits have change the order and some of the wording.
Footnotes, references
Excerpts from my first draft, with footnotes.
- For example, according to the International Energy Agency[1]: “Carbon capture and storage (CCS) is the only technology able to deliver significant emissions reductions from the use of fossil fuels.”
- And Oxford University climate scientist Myles Allen claims[2]: “A global ban on fossil fuels is neither affordable nor enforceable, so capture and disposal of CO2 is the only option. Assuming we don’t want to turn the world over to cultivating biofuels and resort to eating insects, then there will always be some uses of fossil fuels for which there is no effective non-fossil substitute, much as environmentalists hate to admit it. “
- Conversely, climate expert Joe Romm, writing at Climate Progress[3], has written that: “CCS simply hasn’t yet proven to be practical, affordable, scalable, and ready to be ramped up rapidly.”
- While Energy historian Vaclav Smil comments[4]: “…in order to sequester just a fifth of current CO2 emissions we would have to create an entirely new worldwide absorption-gathering compression-transportation- storage industry whose annual throughput would have to be about 70 percent larger than the annual volume now handled by the global crude oil industry whose immense infrastructure of wells, pipelines, compressor stations and storages took generations to build.”
- Recently, the results of a research project in Iceland went against this trend and put CCS briefly back into the news[5].
- In cases where atmospheric concentrations of carbon dioxide are limited to 450 parts per million, mitigation costs increase by 138%, compared to the baseline scenarios in which no CCS is deployed.[6]
- The Paris Agreement[7], signed by all of the world’s governments in December 2015, calls for the Parties “to achieve a balance between anthropogenic emissions by sources and removals by sinks of greenhouse gases in the second half of this century”.
- Indeed, of the 400 of the IPCC scenarios that keep warming below the Paris agreement target, some 344 involve deployment of negative emissions technologies[8]. The remaining 56 models all assume that emissions reduction started in 2010.
- As an example, a prominent published model[9] that limits warming to 2°C envisages primary energy use in the year 2100 to be (in approximate numbers): 25% renewables and nuclear energy; 15% fossil fuels without CCS, mostly natural gas and; 60% fossil fuels and bioenergy with CCS. In this model, 30 billion tonnes of CO2 from fossil fuels will be sequestered annually in 2090 in addition to 10 billion tonnes of CO2 from biofuels.
- The annual mass of 40 billion tonnes of CO2 mentioned earlier would have a volume of about 65 billion cubic metres, for comparison, this is about three times the average annual discharge of the Hudson River[10].
- Basalts are natural CO2 sequestration sites. Exposed basalts, especially in the tropics, are estimated to absorb about 180 million tonnes of CO2 every year[11].
- Basalts on the sea floor react with dissolved CO2 in the seawater to take up about 150 million tonnes annually[12].
- These processes, along with other weathering activity, are important on geological timescales for absorbing CO2 emissions from volcanoes (estimated at around 500 million tonnes per year[13]).
- A recent article in Science[14] by geologist Joerg Matter of Southampton University and colleagues reported on an experiment in Iceland in which volcanically-sourced CO2 was dissolved in water and injected into basalts at depths between 400 and 800 metres.
- One of the best onshore candidate areas for basalt sequestration in the USA is the Columbia River Plateau located in eastern Washington, NE Oregon and western Idaho[15].
- As an illustration of how much water might be required, if attempts were made to sequester all US CO2 emissions from fossil fuels (5.2 billion tonnes in 2014[16]), some 130 billion tonnes of water would be used, approximately half of the annual flow of the Columbia River (240 billion tonnes[17]).
- The most extensive area of basaltic rock on the planet is the ocean floor. One part of the ocean that has been identified as potential location for sequestration of CO2 in basalts is the Juan de Fuca plate in the Pacific Ocean west of Washington, Oregon and Northern California[18].
- There is little public demand for CCS or for government funding it, particularly in western Europe, as Joerg Matter, quoted in the Guardian[19], said: “In Europe you can forget about onshore CCS.”
- To stabilize rising global temperatures requires not just greatly reducing emissions, but getting them to zero.[20]
[1]https://www.iea.org/publications/freepublications/publication/CarbonCaptureandStorageThesolutionfordeepemissionsreductions.pdf
[2] http://www.oxfordmartin.ox.ac.uk/opinion/view/346
[3] https://thinkprogress.org/carbon-capture-and-storage-one-step-forward-one-step-back-c63e2406c581#.ago2arvwl
[4] http://www.vaclavsmil.com/wp-content/uploads/docs/smil-article-2011-AMSCI.11.pdf
[5] http://www.sciencemag.org/news/2016/06/underground-injections-turn-carbon-dioxide-stone
[6] https://www.ipcc.ch/pdf/assessment-report/ar5/wg3/ipcc_wg3_ar5_technical-summary.pdf Table TS2
[7] https://unfccc.int/files/meetings/paris_nov_2015/application/pdf/paris_agreement_english_.pdf
[8] Anderson, K. (2015). Duality in climate science. Nature Geoscience, 8(12), 898-900.
[9] Vuuren, D. P., Stehfest, E., Elzen, M. G., Kram, T., Vliet, J., Deetman, S., … & Oostenrijk, R. (2011). RCP2. 6: exploring the possibility to keep global mean temperature increase below 2 C. Climatic Change, 109(1-2), 95-116.
[10] http://ny.water.usgs.gov/projects/dialer_plots/Hudson_R_at_NYC_Freshwater_Discharge.htm
[11] Dessert, C., Dupré, B., Gaillardet, J., François, L. M., & Allegre, C. J. (2003). Basalt weathering laws and the impact of basalt weathering on the global carbon cycle. Chemical Geology, 202(3), 257-273.
[12] Alt, Jeffrey C., and Damon AH Teagle. “The uptake of carbon during alteration of ocean crust.” Geochimica et Cosmochimica Acta 63.10 (1999): 1527-1535.
[13] Burton, M. R., Sawyer, G. M., & Granieri, D. (2013). Deep carbon emissions from volcanoes. Rev. Mineral. Geochem, 75(1), 323-354.
[14] Matter, J. M., Stute, M., Snæbjörnsdottir, S. Ó., Oelkers, E. H., Gislason, S. R., Aradottir, E. S., … & Axelsson, G. (2016). Rapid carbon mineralization for permanent disposal of anthropogenic carbon dioxide emissions. Science, 352(6291), 1312-1314.
http://www.sciencemag.org/news/2016/06/underground-injections-turn-carbon-dioxide-stone
[15] Zakharova, N. V., Goldberg, D. S., Sullivan, E. C., Herron, M. M., & Grau, J. A. (2012). Petrophysical and geochemical properties of Columbia River flood basalt: Implications for carbon sequestration. Geochemistry, Geophysics, Geosystems, 13(11).
[16] http://cdiac.ornl.gov/trends/emis/top2013.tot
[17] http://pubs.usgs.gov/gip/70039373/report.pdf
[18] Goldberg, D. S., Takahashi, T., & Slagle, A. L. (2008). Carbon dioxide sequestration in deep-sea basalt. Proceedings of the National Academy of Sciences, 105(29), 9920-9925.
[19] https://www.theguardian.com/environment/2016/jun/09/co2-turned-into-stone-in-iceland-in-climate-change-breakthrough
[20] Matthews, H. D., & Solomon, S. (2013). Irreversible does not mean unavoidable. Science, 340(6131), 438-439.
Open-access versions of some of the papers cited above can be found by copying the paper title and doing a search by pasting it into the search box in Google Scholar.
Critical Angle 
BECCS feels a bit over-teched to me… Hmm, sorry, no, it is in fact a joke about rocket scientists. Here is the stone age way of BECCS: Pyrolize wood, keep 10% energy as char, then compost char and use it as soil enhancement. The char does not rot away and thus is sequestered carbon. Google “terra preta”, “biochar”.
Why is this not discussed? Perhaps because it requires an agricultural revolution – making it part of the solution instead of being part of the problem? This takes a lot of work and time and fighting the agroindustrial complex. So, actually, sorry, methinks BECCS is even worse: It is fiddling while the planet burns.
If I focussed on BECCS too much, it was because that’s what the IPCC has done.
I would be very pleased if it could be shown that soil carbon enrichment using biochar or improved grazing practices could increase the carbon content of the soils enough to make a dent in the climate crisis. Others have suggested also trying enhanced olivine weathering, by spreading crushed minerals on beaches in the tropics. It would be wonderful if such approaches, used alone or in combination, were sufficient to reduce atmospheric CO2 concentrations. These methods also likely have benign environmental side-effects, also.
However, the climate crisis was caused primarily by exploiting fossil fuels, not by depleting soils of carbon, so I’m skeptical than recarbonizing the soils will be enough to turn things around in time. Nevertheless, I would be supportive of much more funding for (literally) field testing these technologies. It’s not as if we have the problem licked yet and any solution is likely to involve using every tool that we have in the box.
The proof is the carbon rich anthropogenic pre-Columbian soils in the Amazon. Still fertile and commercially mined. Given the conditions in the tropics (rapid weathering and wash-out of soil organic carbon) one can’t ask for better proof.
There’s more than just carbon depleted agricultural fields (which I bet have alone more potential than BECCS in basalt: Much of modern industrial agriculture can only be sustained with huge artificial carbon-intensive input, for the soils are down to essentially desert). And then there is e.g. reforestation at the boundaries of deserts, perhaps combined with irrigation powered by surplus solar and wind energy. One benefit of biochar is its huge water retention capacity (if done right, I made garden experiments). Then there’s the social synergistics: jobs, food sovereignty, water, resilient small-scale agriculture. And it’s comparatively cheap. Yes, it could be revolutionary. (That’s maybe why lobbyists and astroturfers have worked hard to discredit this ansatz in Copenhagen 2009 and the IPCC prefers to consider industrialist wet dreams.)
Sorry for being impatient 🙂 But it is time for getting seriously impatient… Thanks for your work!
I hear you and it all sounds qualitatively reasonable. But I would like to see multiple, quantitative studies done in different settings to see if it scales up to clean up the mess we’ve made with fossil fuels. Reasonable-sounding technologies need thorough real-world testing before they can be declared fit for purpose.
I should say that I’m also skeptical that a reversion to small-scale agriculture can feed 10 billion and I’m unsure what the effect on human welfare would be if a much bigger percentage of us again had to work in agriculture. It may sound selfish, but I don’t ever want to be a farm hand and most people in poor countries flee subsistence agriculture at the first chance they get.
In a complex problem like the confluence of climate disruption and overpopulation there is no single solution and numbers can only be estimated. Biochar can certainly make a significant dent and is very probably more “economic” (incl. diverse synergistics) than BECCS. (Sorry, I cannot take “economics” seriously…)
I haven’t followed literature and discussion much in the last years. What I have researched is in in the wiki of John Baez’ Azimuth project. My small abandoned experimental garden on sand/granite in Germany/Bavaria seems largely destroyed by flood and stupid. I will try to catch up with latest biochar research and discussion in the next months: One hunch I had is that biochar can also help mobilizing phosphorus. (Depletion of mineral phosphorus reserves is another wall that industrial agriculture is accelerating towards. How then to feed 10 billion without organic agriculture?)
The question if organic agriculture could feed 10 billion is hotly debated. Methinks there is no either-or. For all practical purpose we need to count on both. Current industrial agricultural practise often borders to the genosuicidal (paradigm: Syria) as it depletes soil and wastes ecological resilience. (E.g. the Simbach mud tsunami in Bavaria 2016 from washed-out corn fields with last hedgerows cleared. Been there.)
Being a farm hand need not necessarily be a bad thing. 3rd world slums don’t overcrowd because people don’t like to work with dirt and ride horses or camels. Problem is, small farmers get ruined by industry. My dream job would be organic pig shepherd: Better than throwing pearls at wannabe business administrators.
Now I’m out of time and battery and need go sleep.
P.S.: My guess would be 1Gt C/y from the char + 1Gt extra soil organic C from soil biology effects plus reforestation.
A question I have always wanted answered–or to see someone take a stab at answering–is how much energy would be required to capture carbon by various means, and, then, overall, how much energy would be required to reach the sequestration numbers the IPCC uses in its projections. Presumably this energy must have a pretty low CO2e intensity. As our energy returns on energy invested (EROI) continue their ever faster descent from the fossil-fuel highs of the twentieth century, these sequestration costs would seem to bring our overall mix to or below critical levels that much sooner…
I believe (numbers from memory, so don’t hold me to them) a standard coal CCS project uses 30% more coal to generate the same power as a non-CCS project. Obviously, that will lower the EROEI significantly. Also, CCS does not reduce emissions to zero, there’s still some small fraction that escapes up the chimneys.