3775-year-old wood burial supports “wood vaulting” as a durable carbon removal method (5 emails 9/27/2024 to 10/3/2024)
CDR
3775-year-old wood burial supports “wood vaulting” as a durable carbon removal methodSep 27 2024 11:54AM - Geoengineering News
http://www.science.org/doi/10.1126/science.adm8133
Authors
Ning Zeng, Xinpeng Zhao, Ghislain Poisson, Bryson Clifford, Yu Liu, He Liu, Taotao Meng, Laura Picard, Elisa Zeng-Mariotti, Ben Zaitchik, and Liangbing Hu
DOI: 10.1126/science.adm8133
26 September 2024
Editor’s summary
Trees and plants capture plenty of carbon dioxide as they grow, but most of it is released relatively quickly as foliage and wood decay. Zeng et al. explored entombing trees in clay, creating a wood vault that may prevent degradation for hundreds or even thousands of years (see the Perspective by Yao). Supporting this approach is the discovery of a tree buried in clay about 3800 years ago that the authors analyzed, showing that it has degraded very little over that time. This work suggests that it is possible to create environments that vault away biomass semipermanently. The cost of doing this appears to be lower than other methods of carbon sequestration such as direct air or ocean capture. —Brent Grocholski
Abstract
Six-times more carbon dioxide (CO2) is removed each year by terrestrial photosynthesis than fossil fuel emissions. However, the carbon is mostly returned to the atmosphere by decomposition. We found a 3775-year-old ancient wood log buried 2 meters belowground that was preserved far beyond its expected lifetime. The wood had near-perfect preservation, with carbon loss less than 5% compared to a modern sample. The lack of decay is likely due to the low permeability of the compact clay soil at the burial site. Our observation suggests a hybrid nature-engineering approach for carbon removal by burying woody biomass in similar anoxic environments. We estimate a global sequestration potential of up to 10 gigatonnes CO2 per year with existing technology at a low cost of $30 to $100 per tonne after optimization.
Source: Science
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Sep 27 2024 3:41PM - Michael Hayes
Diesel engines produce 2.7 kilograms of CO2 for each liter of diesel consumed...on a good day and with a new engine.
Until heavy equipment goes C neutral or negative, burying vast volumes of wood will likely not be competitive as a CDR.
I would like to also add that simply harvesting a vast number of trees will trigger a vast amount of CO2 and CH4 emissions due to the rotting of the biomass left behind, both below the surface, ie rotting roots, and above the surface in the form of limbs left to rot.
Some loggers, even today, will bury cedar logs if the price is in an extended slump, yet the C math is far more complex than the volume of biomass that is left in anaerobic clay soil.
As a side note on growing the biomass in clay soil, many trees do not do well growing in clay soil due to limited O2 availability, as such, transportation related CO2 emissions and costs may need to be factored in.
Sep 27 2024 4:52PM - Tom Goreau
Few soils have the anoxic peat required for such preservation.
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
goreau@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
Geotherapy: Regenerating ecosystem services to reverse climate change
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
“When you run to the rocks, the rocks will be melting, when you run to the sea, the sea will be boiling”, Peter Tosh, Jamaica’s greatest song writer
Oct 3 2024 7:27PM - Ning Zeng
Based on the Montreal Project and Carbon Lockdown's Potomac Project, emissions are only 2-5% of carbon sequestered in buried wood. See a 4-min video on an actual Wood Vault construction: https://lnkd.in/guc_2fhh
and the Science paper's Supplemental Materials Section 2 "Life cycle analysis and emissions" (https://lnkd.in/gh7vAKQa)
See my LinkIn post and references there. https://www.linkedin.com/posts/ning-zeng-52869811_a-cheap-low-tech-solution-for-storing-carbon-activity-7247748411779637249-DvTb?utm_source=share&utm_medium=member_desktop
Thanks. Ning Zeng
Oct 3 2024 11:06PM - Michael Hayes
Ning, et al.,
The transportion efficiencies of slashed biomass, even invasive biomass, needs improvement. I could post photos of what modern forest harvesters do, what is left behind, and the speed and scale is impressive for those not in the field. You clearly are aware of the state of the arts in forestry.
Speaking as a retired forester I can easily see that transportation improvements need to catch up to the advanced field harvesters. Trees are rather safe H2 delivery systems and H2 can lift bulk materials. Balloon logging offers a reliable historical reference on heavy lift industrial balloons that used Helium..
The 10 GtC/y CDR scale is slightly larger than all agriculture on this planet, in gross weight, at this time, and H2 fuel can be safely handled in biomass form. If the slashed biomass generated by the tree harvesting for vaulting can be leveraged for advanced H2 based transport, which can also generate Biochar, reaching GtC/y CDR levels via biomass handling in general on a vast scale can likely seriously help scale up a wide collection of needed CDR options.
Best regards
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