A Cheap, Low-Tech Solution For Storing Carbon? Researchers Suggest Burying Wood (msn.com) 82
Researchers propose a "deceptively simple" way to sequester carbon, reports the Washington Post: burying wood underground:
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.
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.
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. "Because here's the evidence...."
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...
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, according to the International Energy Agency.
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.
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. "Because here's the evidence...."
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...
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, according to the International Energy Agency.
Isn't that essentially how coal came into being? (Score:2)
Emulating those conditions should require much less research than complicated new carbon capture schemes.
Re:Isn't that essentially how coal came into being (Score:5, Interesting)
Trees evolved lignin 360 million years ago.
For the next 60 million years, wood did not decompose. It piled up and formed coal seams. So much CO2 was pulled from the atmosphere that the Earth went into a deep freeze: Late Paleozoic Ice Age [wikipedia.org]. Life on Earth nearly perished.
But one heroic little fungus continued to work on the "lignin problem" until it figured out how to digest lignin in a process chemists compare to "untying a knot with a flamethrower". Life on Earth was saved.
The formation of the coal seams was a one-time thing. The conditions can't be repeated.
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Never seen a peat bog?
What you end up with is not "coal" but it is 50% carbon. Left without air in geological storage that percentage would increase over time. So, it is quite possible.
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Ah, such a simple story. The kind that the human brain loves. The kind that gets lots of citations [geoscienceworld.org] and turns into "common knowledge." It must be the truth.
Nope. [pnas.org]
Peat Bogs (Score:2)
The formation of the coal seams was a one-time thing. The conditions can't be repeated.
Then can you please explain the existence of coal-forming peat bogs today? There are certainly not as many of them as there must have been in the carboniferous era but they do definitely still exist.
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You're clearly both right. You're right that new coal of a sort does form even today, but the GP is right that the conditions that formed most of the existing coal seams are gone and can't be repeated. There is a reason the carboniferous is called the carboniferous, after all. The mass and volume of coal produced today is vastly reduced compared to that era. Not to mention that the variety of coal typically created has changed. Of course, there are still plenty of opportunities for wood to be buried before
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Bacteria need three things to turn wood or post-consumer wood products into carbon dioxide:
1. Wood (carbon)
2. Air or water (oxygen)
3. Heat (energy)
Bury the wood deep enough with the right kind of soil on top and you deprive the bacteria of oxygen and energy. If decomposition doesn't halt entirely, it at least slows way down.
So, it could be as simple as separating our wood and paper waste from everything else, compacting it to eliminate any voids and then burying it under an impervious soil such as silt or c
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This of course suggests another, more effective solution: Just stop digging up and burning all that coal up in the first place.
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The problem I have with this idea is that there are two choices to reduce CO2 in the atmosphere here. One of them is to bury wood, and the other is to take that same wood and burn it as fuel instead either to produce heat or to produce electricity, or both. Taken in isolation it seems obvious that burning wood releases CO2 back into the atmosphere, whereas burning it takes it out of the atmosphere. However, it would not be in isolation. The energy generated would be used in place of energy generated by othe
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: Fighting entropy (Score:2)
You are saying this as if earth is not leaking energy into space. The green house effect capture some of the energy that would leak, our problem right now is that the amount of leaking is unbalanced and overall energy levels are increasing. I'm not a climate scientist but I have studied thermodynamics decades ago.
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CO2 insulates, creates the greenhouse effect, and is the dominant factor in the average temperature on the planet. Sunlight comes in, heats the planet, and CO2 in the atmosphere determines how quickly it radiates into space and the amount of heat that builds up on Earth while it does that.
That's not the energy I was talking about.
All the energy we extracted by cracking hydrocarbon bonds and releasing CO2... THAT is the energy we have to put back in the ground. That's the cost of converting the CO2 into so
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"All the energy we extracted by cracking hydrocarbon bonds and releasing CO2... THAT is the energy we have to put back in the ground. That's the cost of converting the CO2 into something we can artificially sequester permanently."
If that is how everything worked we wouldn't have net positive energy generation in the first place. Yes, the overall checkbook needs to balance but it can be paid in places that don't matter [nothing says the energy has to be useful to us for instance] and there is nothing to say
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>If that is how everything worked we wouldn't have net positive energy generation in the first place.
We have net energy generation from hydrocarbons because nature spent a hell of a long time collecting it for us in convenient forms.
> there is nothing to say that we can't pack something more efficient than we pulled out of the ground.
The stuff we pulled out of the ground was 'free' because nature did all the work of storing the energy for us. You can't beat free.
>Also, who said we need to sequeste
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"We have net energy generation from hydrocarbons because nature spent a hell of a long time collecting it for us in convenient forms."
Actually nature spent a hell of lot of time being more or less random and chaotic and we selected hydrocarbons amongst all the various things nature spent the last [insert millions to billions of years] churning up because they were energy dense.
"The stuff we pulled out of the ground was 'free' because nature did all the work of storing the energy for us. You can't beat free.
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Disagree with this a bit. By far, H2O has the greatest effect as far as greenhouse effect. At least 2X and up to 4X (depending in source) the impact of carbon. Having said that, I am not belitling the effect sequestering carbon could have on temps. Probably cheaper than going all solar and much safer than throwing reflectants in the almosphere, imo.
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While trees often begin with taproots they typically develop fibrous root systems. https://en.wikipedia.org/wiki/... [wikipedia.org]
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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.
...so a good, long-term carbon sequestration business model might simply be a Christmas tree farm with a '100% recycled land' business model? Like a coke bottle deposit scheme?
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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.
Re: This idea comes up a lot (Score:3)
Solution: Crop rotation. You log a section of land and then re-seed it with some species that regenerates critical nutrients, fixes nitrogen from the atmosphere, etc.
Of course, lumber companies won't like this. They want to re-plant with commercially viable lumber species as soon as possible. Not some junk like alder.
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Solution: Crop rotation.
Crop rotation can restore nitrogen, but it does not restore potassium, phosphorus, or other nutrients.
Any land that can be rotated with legumes is crop land that could be growing food. The point of burying wood is that trees can grow on hilly and rocky land otherwise unsuited for agriculture.
Of course, lumber companies won't like this.
Lumber companies will love it. It will take billions of acres out of production, driving up prices and profits.
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The point of burying wood is that trees can grow on hilly and rocky land otherwise unsuited for agriculture.
Good luck logging it and burying it. Planting more trees in arctic Canada and logging them and burying is likely to work better than trying to grow crops on it, though.
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You can log it, use it in construction and then bury it when the houses get torn down in 30 years.
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Happened for hundreds of millions of years to make the original coal forests, it did not wipe out forests, but it did cool things down. Modern animals like cows need to be cooked to 145, descendants of dinosaurs (poultry) need to be cooked to 165 to be safe. It suggests to me they were part of an ecosystem that was warmer, they carry pathogens that can be part of their decomposition at temps that would kill anything modern. Climate change is not new, but rather a violently fast return to past ecosystems. Lo
Re: This idea comes up a lot (Score:3)
The recommended temperature you cook food for human consumption at is not related to temperatures of a prehistoric climate. And a pink steak is not completely free of microbes. And salmonella in poultry is a relatively recent issue, and is the main reason we aim for a higher cooking temperature to target denaturing the protiens of specific pathogen.
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It can't be as bad as you think.
Consider the tree farms of the US East coast. There are hillsides that have been planted with trees and clearcut once a decade or so to turn the trees into paper.
This has been going on for generations, and if any fertilizer is needed to keep the trees growing, it must be cheap enough to do it profitably, which implies it doesn't take a lot of energy to make the fertilizer.
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That was optimized for lumber not biomass. Trees grown for lumber grow slow, they can't even keep all the biomass converted coalplants active for much longer. We will soon run out of trees at the current rates of consumption.
For significant biomass for either sequestration or the woodpellet scam you will need much faster growing/depleting species.
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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).
You could always burn the trees first. You're still sequestering a decent amount of carbon, because that's what most of the ash is, but you're not depleting the soil. It will, of course, eventually be turned into CO2 by soil microbes, so I don't know how long that buys you or whether it would be worth doing.
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You could always burn the trees first. You're still sequestering a decent amount of carbon, because that's what most of the ash is, but you're not depleting the soil.
If you burn them efficiently with a triple burner, you don't really get much left over. Basically, you burn the wood once providing lots of air, and use the heat from the fire to heat up additional air, then you mix the hot air with the smoke and that burns, then you pass the exhaust from that through a catalytic combustor, which is very much like a catalytic converter in a car and that burns nearly everything else. Basically you end up pretty much completely burning everything and all the carbon ends up as
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Leading us back to the idea of converting the biomass into biochar, which makes the carbon stable enough that burying it may not even be necessary:
https://en.wikipedia.org/wiki/... [wikipedia.org]
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This isn't true. It's quite possible to produce a self-sustaining ecosystem while removing biomass from it. You need a complex ecosystem not a monoculture and you need to remove a limited amount.
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It is quite true that nature is constantly producing new biomass. The essential nutrients include things like fixed nitrogen and minerals. The fixed nitrogen is fixed over time by nitrogen fixing plants and bacteria from the atmosphere. The minerals come from rocks. It's right there in the basic multi-horizon model they teach in high-school science class. You have your top layer of humus material, your topsoil, sandy/silty material, subsoil, parent material and bedrock. The bedrock breaks up over time and m
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There's a lot more than carbon in that biomass.
I've long thought the solution was to make charcoal out of the biomass (which drives off the hydrogen, mostly as methane IIRC), leaving close to pure carbon. You can capture the methane and use it for whatever you want. Bury the charcoal and nothing I know of will digest it.
I'm sure there's some good reason this doesn't work but I can't imagine what it is. Seems a lot cheaper than capturing CO2 from the air and trying to store it in deep caves.
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Most of the non-carbon nutrients are in the leaves, so let those decay into the soil while you sequester the carbon-rich trunks deep underground.
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Why not just build? (Score:2)
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Houses framed from old-growth hardwood might last for centuries.
Houses framed from fast-growing pine farmed over the past ~50 years have nails and screws popping out due to warping within a matter of months.
Wood-framed houses built since ~1960 will be lucky if they're even still *standing* another 50 years from now...and by that point, their waferboard roof & wall sheathing will have been replaced multiple times, and most of the interior frame will be sistered to boards that were themselves originally s
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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.
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Grow the trees in West Virginia.
Bury them in abandoned coal mines.
Worst case, you're replenishing the coal supply s few mega-years from now...
Use kelp (Score:2)
The other thing that makes me wonder: is landfilling all the plastic crap we throw away now less of a horrible thing than we used to think it was?
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> is landfilling all the plastic crap we throw away now less of a horrible thing than we used to think it was?
If we were putting it somewhere it wouldn't break down into microscopic sized bits of "yes, it's still plastic" and leech into the water supply... yes. Unfortunately that isn't how it goes and I think the spread of microplastics throughout the environment is likely a bigger issue than can be offset by the sequestered carbon.
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The plastic was already sequestered as oil before we dug it up. It's at best carbon neutral. And not really since the associated lighter fraction of petroleum was probably burned as gasoline.
You can't use plants to sequestor carbon (Score:4, Informative)
Plants breath. We don't think about it but they do.
That means they've got mouths. Lots of them. Little holes that pull in the CO2.
Just like your mouth they can close them, and when it gets hot that's exactly what they do. Because it preserves water.
So we can't plant our way out of this mess. As we pump CO2 into the air it gets hotter faster than the plants can counter act it. The heat causes droughts by breaking the water cycle and the plants pull in less CO2.
You can find videos on YouTube explaining this in detail with the math showing exactly how/why we can't plant our way out of this mess.
And again, these guys know this. They've got the math chops and education to figure that out.
All this carbon capture crap is just shit the oil industry & the Saudis push to keep us on dirty energy as long as possible. They're *desperate* to buy time because we could do the switch way faster than they can hope to retool their economies.
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I live at fairly high latitude. We've got lots of plants, including trees. They grow pretty well (i.e. they take carbon from the atmosphere and turn it into wood). I guess there must not be any plants further south because it's hotter there hey? And there definitely weren't any plants in, say, the Devonian period, when the global temperature was up to 10 degrees wamer than today. Weird we name gardens after it.
You either missed the point (Score:2)
Again that's because a combination of droughts caused by breaking the water cycle and increased heat and temperatures means that plants taken less CO2 in order to lose less water.
We can't plant our way out of climate change. The only way forward is to get off of fossil fuels. Anyone who tells you anything
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When you grow a plant, the carbon that makes the plant comes from CO2 in the air. The reason you can't traditionally use plant as carbon sequestor is because eventually the plant decomposes and the carbon stored in the plant itself is released back as CO2. That's why they are looking at what if we could stop that decomposition by burying it in some special way. That kind of makes sense.
Now I agree with you that it is more of a priority to slow/stop the pumping of CO2 in the atmosphere. But we are 8 billion
I understood the point of the article (Score:2)
And honestly this is before the obvious fucking problem with growing plants just to bury them when we have water shortages all over
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My point was that the idea of sequestering carbon in plants whether you're burying them or not is fundamentally flawed because long before you get to the point where you can store a bunch of carbon in plants we're going to be putting out more CO2 than they can possibly absorb because they're going to be cutting back on their absorption as drought and heat becomes a problem.
If you're not burying them then it doesn't really work since you're greatly limited by the amount of plant life the surface can currently support (which is constantly declining due to human activity).
Burying them means you're no longer limited, so it potentially makes a big difference.
And you don't need to take out enough CO2 to offset all our industrial CO2 emissions, just like solar alone can't replace all our power generation needs. You just need to help a bit for it to be part of the solution.
And honestly this is before the obvious fucking problem with growing plants just to bury them when we have water shortages all over the world in places we need to be farming.
So don't d
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I sort of wonder about just using a woodchipper and dumping the wood in abandoned mines. There are a lot of unused spaced underground like coal mines which are too unstable to use for anything else, so dumping compacted wood there for the long term may be an idea. With a good shredder and a hydraulic press, one can press the wood into many shapes, so whatever can go into a mine cart easily and stored.
As for a plant to grow, I remember a few years back, this exact topic being mentioned, but using hemp beca
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Oh yes, that's why the hottest areas of Earth, near the equator, are barren desert.
Not yet. The Amazon is beginning to die back, apparently, though, due to heat and water stress. Many other locations around the equator are desert.
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Agreed on most carbon capture "tech" being stupid and useless, and for the most part, probably actively harmful (if any of it were to take place, which to date, it hasn't really). Ditto for most "geoengineering" ideas. Thing is, we absolutely can use regenerative techniques to sequester carbon, and lots of it. While huegelkultur is a millennia-old technique and does work for increasing soil fertility and moisture retention, burying wood may not be all that useful to offset climate change, since even if i
No need to bury them... (Score:2)
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While the significant growth of a loblolly pine is roughly 30 years, in terms of carbon fixing maxima vs time you're looking at between 15 and 20 years max. That 30 year mark is when growth drops off almost completely, not the start of the drop off.
Ummmm.... (Score:1)
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planting trees? (Score:1)
Can cheap home construction companies use this? (Score:2)
If they can get credits for every piece of scrap they've burried in the front yards of subdivisions, they might never pay taxes again.
In a million years..... (Score:4, Funny)
Sentient lizard people discover vast quantities of wood underground and decide it could be used as fuel to keep them warm at night.
turn it into charcoal (Score:2)
Easier solution? (Score:1)
Instead of going thru all of the work it would take to bury the trees, why not just burn them down! It will be a lot easier and then we could just.........oh, wait.
So, the answer to global warming is... (Score:2)
Every carbon sequestration story is dumb (Score:2)
The top polluters won't stop polluting so the only other option provided is the ridiculous bounce-house carbon credit system, really the same as Indulgences in the catholic sense. You're not going to address global warming with the so-called free market.
couldn't we just build stuff out of wood? (Score:1)
Wood is a fanstastic construction material. There's been some really interesting research as to how to make it even better.
For example.
https://www.nature.com/article... [nature.com]
Not sure, might be too energy intensive, after all if you use 90% of the carbon savings processing it into a higher strength building material that's obviously not a great plan. However further research can perhaps find a better way.
Can you make 100 story skyscrapers with it ? No , but I would argue we shouldn't even be building 100 story sk
Wouldn't hemp or bamboo be better? (Score:2)
Both hemp and bamboo grow many times faster than trees. Wouldn't that be a better carbon dump?
Re: Wouldn't hemp or bamboo be better? (Score:1)
Hemp can't burn in a forest fire. That's why we need to burn up all the forests, then let the rain wash away the ash.
Again? (Score:2)
The simplist method (Score:1)
is to just burn all the forests. Then no more carbon. Only ash, that the rain washes away.