Dead trees keep surprisingly large amounts of carbon out of atmosphere | Hacker News Reader

Dead trees keep surprisingly large amounts of carbon out of atmosphere

phys.org

91 pointsPaulHoule86 comments

Interestingly earthworms went extinct in most of north america after the last ice age, and their re-introduction in 1500+ means they are making their way through organic matter in Canada's boreal forests that were previously sequestering large amounts of carbon. No way to roll it back though.

https://natural-resources.canada.ca/stories/simply-science/e...

Then the fix to climate change is clear, we must exterminate the worms!

When Worms came out in '95, I had a feeling there was something deeper, more profound to it, but I couldn't tell what it was.

Now it all finally makes sense!

hippies loved earth so much, oil companies started to distribute drugs between people [btw drugs are made from oil...no kidding] (just alternate universe joke)

worms armageddon

who would thought that one worm can emit as much co2/methane emissions as a sheep launcher...

> "We can expect the carbon pool stored in these forests to increase substantially,"

Interesting. I would have guessed that any kind of forests have quite limited cap how much carbon it could retain in dead wood, and that this cap will be pretty much fixed. Unless something will stop natural decay processes releasing the carbon back to the atmosphere I don't see how existing grown forest could increase its capacity, since I suppose it is already at its equilibrium.

(Unlike peatlands, where most of accumulated carbon remains underwater, so it presumably has much larger capacity.)

Simply said, without "burying or sinking wood mass" I see no easy way to prevent carbon from returning into the atmosphere. Basically if we need to take carbon from the atmosphere, we should ideally put it back from where we have been mining it for last couple of centuries.

Don't forget about the root system, a large part of a tree is underground, so naturally buried

I'd call it semi-buried, since it is not isolated from the atmosphere, so in a long term I suspect that almost all its mass gets re-circulated back again – still through microbes, fungi, insects, and perhaps living root systems of surrounding trees. (Last time I tried to get some data about how much carbon remains in the soil after aerobic wood/plants decomposition in agriculture I remember it was pretty much negligible. Forest have way higher limits for maximum soil carbon accumulation, but this limit is reportedly reached after about three centuries of uninterrupted growth.)

Depends on the ecosystem. Anything embedded into bogs or peatland like roots will generally not decay at all, instead building up a very thick layer of captured carbon as peat.

Plants get most of their carbon from CO2 anyway, so in most cases carbon accumulates in the loam (outside of intensive agriculture at least). They produce far more than decomposers have a use for and that's how CO2 accumulates in soil. It only needs to be replenished by the rest of the carbon cycle because of erosion.

> I would have guessed that any kind of forests have quite limited cap how much carbon it could retain in dead wood

The article says, "We found that a forest that's developing toward old-growth condition is accruing more wood in the stream than is being lost through decomposition" and "The effect will continue in coming decades, Keeton said, because many mature New England forests are only about halfway through their long recovery from 19th- and 20th-century clearing for timber and agriculture".

Ah, overlooked they actually acknowledge the "cap" directly in the preceding paragraph, and even put it into "coming decades" time frame. Makes much more sense now, thanks for the pointer!

Still a bit confused about the emphasis in wood deposits in "streams" – reportedly way more effective, but I'd guess with very limited capacity to really "lock" the mass – compared to regular hummus – not that effective, but for forest with couple of centuries of growth ahead I'd guess way more capacious. Good news either way, though!

“Coming decades” is an understatement. It depends on local conditions but douglas fir pines in the PNW take 200-300 years to decay completely, so that’s centuries more of carbon capture as long as we let our forests rewild. Realistically a forest becomes old growth once there are at least three generations of trees in various states of decay. That may decades in warmer climates but much longer in the north.

Reading between the lines in the article (which is of course always subject to incorrect interpretation) I think the reason for the focus on streams is just that nobody else has looked at that before and thus it is a factor not previously accounted for. Other sources have already been accounted for - they may be worth more than what is in streams, but it is already known so the article didn't mention them.

It takes a long time to reach that equilibrium and something can disrupt it along the way. Inevitably what happens is, as the amount of dead wood increases, so does the fire risk, and when it burns its all returned to the atmosphere. This is compounded by the fact that wildfire impact appears to be increasing significantly as the climate changes. Alternatively, humans cut it down because theres lots of large dense wood to grab.

> when it burns its all returned to the atmosphere

Not always. Depending on fire some of it is turned into charcoal and then never returned.

Agreed, "all" is an unfair word. Thanks. It's more accurate to say the majority of it is returned to the atmosphere. Less than 1% of burned fuel typically becomes organic carbon, but also not all of the biomass exposed will actually burn either. There's also trace amounts of other content and a lot of particulate matter (which one may or may not consider as carbon 'returned to the atmosphere' I suppose)

1% add up if we can do it worldwide on a regular basis. (likely yearly, but you need the proper forester for each forest)

For that <1% left as carbon, comes >75% released as carbon dioxide and carbon monoxide, which needs to be recaptured. Tree capture by itself is already too inefficient -- you need to cover roughly the entire area of new mexico with trees to account for just one year of America's emissions. If you're only sustainably capturing 1% of that capture, we're nowhere near the order of magnitude necessary to be impactful on a global scale.

Further, even if we didn't face the issue of running out of land, we don't appear to be able to actually plant trees fast enough and well enough (many of the "millions of trees" planting projects, especially in developing nations, have had tree survival rates of under 10%)

Forests help and are part of the strategy, but fundamentally not moving the needle.

Not that this solves it but we could easily cover a whole state in trees. Have you seen Indiana and Illinois. Those states are entirely made out of corn. At this point it isn't an engineering problem it's just an economic one.

Dead trees can exist as furniture, flooring and buildings too. Stored carbon with ancillary usage.

efficiency of plants - 1%

efficiency of photovoltaic - 20%

so photovoltaic is 15 times more land efficient then burning biomass. so we absolutely need trees to provide ecological functions. but in era of 5kwp PV array paying itself in 5-6 years(and still working afterwards), to heat water... its is ridiculous to cut trees and burn them to have hot water. 80% of time Canadian citizen can have 100% solar hot water (PV), less then 100% rest of the year.

I am happy to see that PV is being deployed at incredible speeds. But dismayed at the lack of large scale storage projects & international interconnects.

Is distributed scale storage projects not enough? The grid doesn't need huge storage projects if every house has a house-sized battery and an increasing number of cars can double as a storage buffer (V2G/V2X). Both of those things are statistically hand-in-hand with current PV rollouts, not always sold together, but they form a virtuous cycle for the average home owner if a home can manage PV, storage, and EV all together to (selfishly) reduce reliance on the grid and keep energy patterns much more localized (if not fully "off grid").

A PV-heavy grid potentially starts to look a lot more distributed in interesting ways like scale than the traditional grid which was always more centrally orchestrated than it sounded.

Not every house has enough space for battery storage. And management of millions of small batteries is harder than management of thousands of bigger batteries. Millions of small batteries are also vastly more expensive than thousands of bigger battery projects.

> Not every house has enough space for battery storage.

Then it becomes a building/complex/neighborhood community building problem in some cases. The shift to a properly distributed scale is that it can be bottom-up rather than top down. Also, some large scale projects may still be needed, it isn't an either/or, a mixture of provides flexibility in the long term. But you certainly need to worry about planning fewer large scale projects if you are expecting a market full of small ones.

> And management of millions of small batteries is harder than management of thousands of bigger batteries. Millions of small batteries are also vastly more expensive than thousands of bigger battery projects.

The cost is more distributed rather than being only one or two infrastructure companies in a region. The management is more distributed with more entities involved. Top-down control is harder, but in some ways that is as much a feature as a bug. Local batteries can prioritize local needs, that's a feature versus "just do what your central provider wishes". Grid-wise needs become a larger market with more players, which also means more competition and more interesting prices.

large scale for me is every house has water tank, which can drain tens of kwh every day. cars which sit on parking lots for 80+% of day... 11kw charger can supply 30 miles of range per 1 hour of shopping, bowling, movie watching... and you do not need V2X, just plug with relay/lock. (esp32+nfc reader for billing)

You need to also factor in the efficiency loss of turning electricity into captured carbon, plus the emissions made mining and then manufacturing and installation and disposal. It is still pretty good, but it isn't basically free like letting trees grow, plus there are other benefits to having large mature forests.

Sorry, just to clarify: OC is about sequestration of carbon, not using trees (biomass) as fuel, right?

Which I oppose; my own governor is arguing that exporting wood pellets is a net gain. Face palm.

That said, learning about biochar is on my todo list. I do forest restoration work (volunteer) and am excited to try anything which helps build topsoil, store carbon, hastens reforestation. example question: So we'd capture that wood gas when making biochar...?

Otherwise, I agree with all. Especially comment elsethread about our existing "distributed storage" system(s) like hot water tanks and EVs at rest.

Fortunately, misc startups are trying to tap into that potential. eg combining heat pumps and water tanks, residential district heating. eg virtual power plants (peer-to-peer systems) aggregating residential batteries (EVs, power walls, and soon appliances) into grid level storage.

It's such an amazing time to be alive. The opportunities are insurmountable.

It's always ridiculous to cut trees for firewood. There is no need, since there is so much dead firewood lying around, and so many trees die every year, and since most people use much cleaner natural gas for heating. As for oil and gas, those are still cheaper, denser, and more portable -and even more sustainable when you consider the mining for rare earths and lithium- than any renewable energy source.

Green trees are not used for fire wood or for paper. Burning green wood makes for terrible fire wood it also causes issues with chimneys due to having more Creosote.

It is illegal In The logging Industry to use merchantable wood for paper or fire wood. Wood has grades and graded wood is worth a lot more than fire or paper wood. Paper wood also has a grade but it is a low grade. Often firewood can be shipped to paper mills as an example.

Totally fallacious argument. Trees grow by themselves in much of the world. They can be harvested with very low investment and directly contribute to a reduction of carbon in the atmosphere, as it now is the tree.

In N Stephensons “Anathem” there are “fuel trees” and a couple paragraphs describing how they are ‘cooked’ for hydrocarbon fuels. I like trees and his vision of a future where genetically modified trees are the best way to collect solar energy and then harvest and store it. Solar panels are cool but one of the themes of the book is civilization over many millennia, and I can see how he arrived at his conclusion that most tech doesn’t work as well as trees.

Sounds like that isn't far from the truth. Cooking wood in an anoxic environment creates wood gas and charcoal. Wood gas can be burned as it comes out of the retort or can be refined into methanol and other hydrocarbon fuels. The charcoal product is a high quality activated charcoal. That can also be burned as fuel or charged and put back in the ground as biochar.

One can get about twice the liquid fuel from wood by reacting it with hydrogen than one can get from the wood itself. Wood is (simplistically) carbohydrates. So, C(H2O) + H2 --> CH2 + H2O. This treats wood more as a carbon carrier than an energy carrier.

Indeed charcoal fueled the early stages of the industrial revolution, and its massive production was one of the primary reasons Western Europe lost most of its forest cover. As wood became scarce, charcoal was replaced by the more difficult to extract coal and lignite.

There aren't enough trees to support industrial civilization. Britain was burning coal before the Industrial Revolution and would have quickly exhausted all land for wood. Wood is useful for other things, buildings and paper would compete with fuel. It is the same problem with turning food crops into fuel.

Solar doesn't require high tech. We use solar panels cause we are good at making circuits. But solar thermal with mirrors should work for lower technology. They wouldn't have the chips for controlling mirrors, but could have some system of central control or just have people move them.

There aren’t enough trees in Britain, that’s for sure! In places with lots of trees and not a lot of people, wildfires burn off a considerable amount of energy stored in dead wood. Canada, for example.

It does work, but the problem is gasoline has distorted our view on how much energy we are actually using. Most people would shrug at using a single gallon of gas to drive to the store. But telling them they gotta cut down an entire tree just to drive to the corner store doesn't fly as well. Of course if we used all the energy in the tree instead of just what can be distilled off it would reduce the amount used quite a lot, but nobody is going to switch to steam boiler powered cars that they gotta fire up 45 minutes before hand.

I dont even know where to to start with the math, but I always wondered if there is not a viable carbon capture business in just growing and burying plants.

Get some fast growing plant like Japanese Knotweed or bamboo, grow it out for a year, harvest and dump the biomass into a decomissioned mineshaft to minimize contact with the atmosphere. Rinse and repeat.

Nope. Philip Mason debunked #TeamTrees as yet another, completely pointless MrBeast vibe cause.

Better off with bio-CSS using GMO kelp or algae, e.g., biomass that grows faster and doesn't rot or burn.

I don't know what #TeamTrees is, nor do I know what MrBeast's involvement in it is. I only know _of_ MrBeast because of some workplace controversy that spilled on to the general internet recently.

I also did not specifically say trees need to be used. I mentioned fast growing things like bamboo. If there is another biological organism (GMO or not) that accumulates carbon-rich biomass faster, then I'm interested in understanding how that compares to more modern CCS techniques that require electricity for example.

You have a good idea. Ignore the armchair idiots. Another take on this idea is using plankton that has been seeded with iron.

https://www.whoi.edu/know-your-ocean/ocean-topics/climate-we...

If our civilization would switch to individual wood houses, assuming that cut trees were regrown, that would allow to capture quite a sizeable chunk of carbon as well.

Those planks and beams will still rot, burn, etc. None of this is in any way a long term solution for anything it seems.

As they rot, people would replace them, so overall captured carbon will be maintained as long as our civilization alive.

My only concern is that building those houses might actually emit more carbon than they are supposed to keep. But assuming that we moved from Oil era to Nuclear and/or Renewables, that should not happen.

Planks and beams rot substantially slower than they take to grow if built correctly. My house was cheap labor housing in the 1910's so no particularly fancy practice and only the exposed wood has been partly replaced. I've been told some of the beams were even recycled from Holland's old wooden shipping fleet.

If the structure is properly maintained and roofed it will be hundreds of years before rot is an issue. You can also design wood structures that don't easily burn, atleast not any more than large buildings are already prone to being destroyed by fire.

It doesn't matter if it rots, burns etc -- all that matters is that it rots slower than the time it took to grow the wood it was made of

Eg:

You have a forest of trees that take 20 years to mature

You cut the trees and regrow the forest every 20 years

You use the timber to build houses (or furniture or whatever) that are _on average_ replaced after 60 years.

This will pull 3x the carbon from the atmosphere than just the forest by itself

Fascinating idea. I suppose you can't build sky-scrapers with wood but surely you could build the vast majority of family houses.

You probably want concrete around the lifts but otherwise you could use timber.

https://en.wikipedia.org/wiki/Ascent_MKE

They do, and, mostly they will eventually rot and release the carbon back - but it may take hundreds or thousands of years - if ever - for a forest to reach equilibrium where it's emitting as much as it's accumulating.

One way humans can improve on this is by making charcoal out of wood and burying it or just spreading it on soil. This drastically improves the fertility of the soil improving the rate that that soil can sequester carbon by growing trees even faster, and, as long as the charcoal is mixed in soil and not in a huge dry pile on top where it might burn, this process need never reach an equilibrium and can keep accumulating more and more carbon, more and more fertility and water retention capacity, more and more abundance of food production. This is what the ancients did in making terra preta in South America and similar charcoal-infused soils that have been found all over the world.

We do this where I live in California. It's a way to reduce forest fuel load while increasing carbon sequestration and fertility. Only cost is labor. It's theoretically possible to do at large scale with machinery instead of people, though the attempts I've seen have not proved viable. For a low expense human-scale way to do it, just making big piles and burning them from the top down (so no smoke) - piling more and more fuel on as it burns, and then dousing with water once it's mostly a big pile of coals, works quite well. With the addition of a big metal ring for a kiln, efficiency can go up even more from (very roughly) 50% of carbon turned to charcoal, to maybe 80 or 90%. Numbers vary considerably. But in all cases, the amount of carbon moved from the rotting or burning cycle to permanently sequestered is significant.

Compared to the short term carbon sequestration of building things out of wood (99% of which will burn within a few centuries), these soils have lasted thousands of years. There must be some mechanism that will eventually recycle this carbon back to the atmosphere but it may be on the timescale of hundreds of thousands of years for most of it.

Trees and other plant life store carbon as they grow, and release it as they decay after death.

Forests will store carbon as and while they are growing, but as and when they reach a stable size they will stop storing additional carbon. That is, carbon stored by growth will equal that released by decay.

It will be reduced significantly, but I wouldn't expect it to actually break even for hundreds of years atleast, if then. Some material is always going to keep getting buried deeper and deeper except for a few areas prone to very high levels of erosion.

I still like: Grow plants/trees -> create plastics from them -> use plastics -> bury plastics forever

Otherwise plants/trees are just a type of carbon battery - pull carbon, burn for fuel, carbon goes back out, gets pulled back in again.

Do we need to grow plants to create plastics anyway? Wouldn't be better to just capture co2 and convert them to plastics (or other long lifespan products) directly

Methinks the word "just" in "just capture CO2" is doing a lot more work than you think.

As my peer comment hinted at, I think "just capture co2" is the part that plants are really good at. However, yes, the general approach is: capture co2 -> make plastics -> use plastics -> bury plastics forever. And "capture co2" can be "grow trees" or "grow algae" or "create a machine that pulls carbon out of the air" or whatever :)

It does take considerable energy to capture and store that carbon when it is only a small fraction of the atmosphere. Trees may not be as energy efficient as us building a dedicated process for it, but growing trees is basically free and it isn't like we are lacking land area to do so. Farmland utilization has been dropping for many decades all across the globe, and even if that didn't happen we would still be very far from running out of suitable tree growing land since trees can grow everywhere but the harshest deserts.

The question is how much of that carbon turns to methane in organic decomposition.

If that fraction isn't negligible, we'd be better off burning it. Determining that fraction, across a range of conditions, is nontrivial.

I'm very confused by this -- does the rate rate of carbon release matter more than the total volume? Won't the carbon in the trees eventually be released, just on a slower timeframe.

I'm not sure what you question is getting at, but yes, the carbon will eventually be released from any wood. If wood-as-carbon-storage was going to be actively applied towards climate change, then it would be important to control the rate of released, by, for example, using the wood in buildings, burying it, or submerging it in water, so that it wouldn't decompose from fungus or termites.

Sure, but it being delayed still matters a lot, particularly if it's "renewable" in the sense that trees falling into streams and being preserved underwater will be replaced over time by other trees that fall into that water on top of them.

It's the same logic for construction materials. A house has dozens of trees worth of lumber in it, and that carbon is now trapped in the house for however many decades it takes until the house eventually burns down or rots. Meanwhile the trees that were cut regrew, so the total "inventory" of trapped carbon has increased. (Appreciating of course that the lifetime carbon cost of the emissions required to maintain and climate-control a house will far exceed the modest value of what is trapped in its walls, but all of this is just for the sake of argument.)

my old boss had an idea - "bury trees".

There's a bit of nuance to be filled out, like challenges of forest plantation monoculture and so on, but it always sounded quite practical to me. Iirc the idea derived from "coal".

Why do you have to bury them? Can’t you just let the logs sit on the forest floor?

Decomposition returns carbon dioxide to the air. Or worse, methane, if there isn't enough oxygen.

Don’t things decompose underground as well?

The carbon stays underground.

They release their carbon as they rot or otherwise consumed. That's why the article talks about wood in cold streams, which rots very slowly.

In the long term they will decompose and return vast majority of its carbon back into atmosphere. Blame fungi and bacteria.

Maybe we can make coal powered earth movers in order to bury the trees.

If you can do it without emitting more net carbon - chopping down and moving trees, digging holes - it might work.

Better yet sink them in the deeper parts of the ocean. Below a certain depth wood loses its buoyancy due to the pressure levels of the water. (I think)

Of course, ships sink all the time.

Unfortunately we don't really have enough deep freshwater to bury them in. Below the thermocline freshwater has little oxygen and logs can last till the turn to fossils.

With saltwater it's a bit trickier because it's decently oxygenated even to depth and there is a lot of life dedicated to breaking down wood in the ocean. If you can get it to sink into the muck it lasts a lot longer though.

Carbon sequestration!

I grew up in an area known for coal and logging. Ever since I heard of sequestration brought up I thought the area sounded perfect for it. Fell (maybe mulch) the trees, kiln dry to remove weight/moisture, and toss them down a mineshaft.

It always felt a bit peotic to 'reseed' a coal mine

Kiln drying is an interesting idea to speed it up and prevent premature rot, but might offset some of the carbon impact since most industrial kilns use fossil fuels directly or upstream if electric.

Maybe it would be more effective to drop wet lumber off in the desert for a few years by rail before moving the dry lumber to permanent underground storage. This assumes two stages of transport to and from the desert would cost less carbon than transport to a kiln and then to storage.

I’m not convinced that the wood even needs to be dried before burying, though.

Ehh if you are just going to bury it kiln drying wouldn't really be that helpful. Wood in open air will dry out pretty well just sitting for two years. Commercial wood is only really kiln dried so that nobody has to store it for a year or two first and they can sell it before as much of it warps and twists due to being cut while green which makes less of it able to be sold. With a large enough pile, even if it is left uncovered, only the top couple logs or boards will get wet from the rain and if a small percentage of it rots or grows some fungus, well it wasn't there to get built into other things anyways so it doesn't matter.

1. Build out nuclear fission (100x current use)

2. Store spent fuel in massive wooden dry caskets. (500-1000x steel)

3a. Float caskets to Antarctica

3b. Offload via rail to South Pole

4. They stay frozen for a million years and don't rot. Problem solved.

Problem is nuclear reactors just don't make all that much spent fuel, so the amount of wood used to crate it up would be negligible.

Edit: I think I've thought of a good alternative though. Instead of crating up the nuclear waste, it could be randomly dispersed in forests around the world to scare people away from those forests, thereby creating nature reserves which should last for generations.

I've considered something like this. Log on the lee side of a mountain range, haul the logs (downhill!) to the arid plain on the lee side, stack loosely, repeat. An electrified highway could allow much of the process to be powered via nuke energy.

Basically any place where you've got high timber production within a reasonably short distance of an arid area could make for a relatively low-tech sequestration/storage pipeline.

The right forest fire will turn trees into charcoal and sequester the carbon. However doing this correctly is really tricky. There are many different forests and they all have slightly different needs. Make sure your government allocates enough money to proper forest management. Make sure that you oppose "environmental" groups that have heard smokey the bear years ago and think all fire is bad thus they get court injunctions against prescribed burning to the long term harm of the forest.

There has been a proposal to salt and bury biomass. At sufficiently high salt concentration anaerobic decomposition becomes energetically unfavorable. It wouldn't have to be wood from large trees.

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