A Cheap, Low-Tech Solution For Storing Carbon? Researchers Suggest Burying Wood (msn.com)
- Reference: 0175147719
- News link: https://news.slashdot.org/story/24/09/28/0418244/a-cheap-low-tech-solution-for-storing-carbon-researchers-suggest-burying-wood
- Source link: https://www.msn.com/en-us/news/us/this-3-775-year-old-log-may-hold-the-secret-to-slowing-climate-change/ar-AA1rgy5m
> Forests are Earth's lungs, sucking up six times more carbon dioxide (CO2) than the amount people pump into the atmosphere every year by burning coal and other fossil fuels. But much of that carbon quickly makes its way back into the air once insects, fungi and bacteria chew through leaves and other plant material. Even wood, the hardiest part of a tree, will succumb within a few decades to these decomposers. What if that decay could be delayed? Under the right conditions, tons of wood could be buried underground in wood vaults, locking in a portion of human-generated CO2 for potentially thousands of years.
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> While other carbon-capture technologies rely on expensive and energy-intensive machines to extract CO2, the tools for putting wood underground are simple: a tractor and a backhoe.
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> Finding the right conditions to impede decomposition over millennia is the tough part. To test the idea, [Ning Zeng, a University of Maryland climate scientist] worked with colleagues in Quebec to entomb wood under clay soil on a crop field about 30 miles east of Montreal... But when the scientists went digging in 2013, they uncovered something unexpected: A piece of wood already buried about 6½ feet underground. The craggy, waterlogged piece of eastern red cedar appeared remarkably well preserved. "I remember standing there looking at other people, thinking, 'Do we really need to continue this experiment?'" Zeng recalled. " [2]Because here's the evidence ...."
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> Radiocarbon dating revealed the log to be 3,775 years old, give or take a few decades. Comparing the old chunk of wood to a freshly cut piece of cedar showed the ancient log lost less than 5 percent of its carbon over the millennia. The log was surrounded by stagnant, oxygen-deprived groundwater and covered by an impermeable layer of clay, preventing fungi and insects from consuming the wood. Lignin, a tough material that gives trees their strength, protected the wood's carbohydrates from subterranean bacteria...
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> The researchers estimate buried wood can sequester up 10 billion tons of CO2 per year, which is more than a quarter of annual global emissions from energy, [3]according to the International Energy Agency .
[1] https://www.msn.com/en-us/news/us/this-3-775-year-old-log-may-hold-the-secret-to-slowing-climate-change/ar-AA1rgy5m
[2] https://www.science.org/doi/10.1126/science.adm8133
[3] https://www.iea.org/reports/co2-emissions-in-2023/executive-summary
This idea comes up a lot (Score:2)
Grow a lot of biomass, then bury it.
Sounds like a great way to remove carbon. There's an obvious flaw, though. There's a lot more than carbon in that biomass. You grow a bunch of stuff on a patch of land, remove the biomass, then try to grow more stuff, and you quickly find your land won't grow much any more. To keep the land fertile you either have to fertilize it (defeats the purpose) or allow the stuff to decay, or burn it (either one releasing the carbon).
Fighting entropy (Score:2)
We want to reverse entropy locally without using energy to do so. The laws of physics have a problem with that.
All the energy we've ever released by burning hydrocarbons needs to be put back into the ground along with the carbon. Plus some, because every process ever has waste heat, it's unavoidable.
Re: (Score:2)
Tree roots grow down more than out, so they don't deplete the surface dirt as much as farming does. The roots also stay in the ground when you cut down the trees, and the leaves rot into a new surface layer, so some of those nutrients stay there for the next tree. Simple undergrowth is similar to letting a field go fallow for a season, so I think soil depletion will be negligible.
Re: (Score:2)
I can't help but wonder how much carbon is put in the atmosphere by the chainsaws that cut down those trees and the excavators that bury them.
Why not just build? (Score:2)
Have you seen the price of lumber lately? Can't we actually simply plant trees meant for growing for lumber? We have wood frame houses still standing after centuries. While it isn't millennia, it is definitely sequestered for a long time.
How do you know whether someone will dig it up? (Score:2)
It's not like we can predict what the land will be used for over the next several thousand years.
Isn't that essentially how coal came into being? (Score:1)
Emulating those conditions should require much less research than complicated new carbon capture schemes.