Planting trees not always an effective way of binding carbon dioxide
gu.se
gu.se
The emphatic message of the research paper is basically like, "tree growing to sequester carbon is very complicated, there's a lot we don't know, and there are a ton of different outcomes depending on how/where the tree growing is carried out."
One part of the paper I found most interesting was the section on nitrogen fixing microorganisms; they made it seem like the nitrogen fixation occurs via microbes pulling nitrogen from the soil and making it available to the plants. However my understanding is that those nitrogen fixing microbes pull N from the air, not the soil. Even good ol' wikipedia says "The bacteria are filamentous and convert atmospheric nitrogen into ammonia via the enzyme nitrogenase, a process known as nitrogen fixation." (https://en.wikipedia.org/wiki/Frankia) ... Undoubtedly there are microbes that can mine nitrogen from the soil, but why focus on those when the real bang-for-your-buck nitrogen fixation occurs when pulling nitrogen from the atmosphere.
Anyhow, great research paper, crappy summary.
Free living, nitrogen fixing bacteria are free living and have a protein that allows them to fix nitrogen to allow faster growth than the bacteria that need to get their nitrogen through other processes. They are often anaerobic (or functionally anaerobic) and so flourish in areas that are oxygen poor (like soil and decomposing organic matter) and by fixing the nitrogen present they enable other organisms to live there (their nitrogen fixing allows fungus to become established in the decomposing organic matter - the bacteria themselves aren't doing the decomposition). https://en.wikipedia.org/wiki/Paenibacillus_polymyxa is one such species of nitrogen fixing bacteria that forms a biofilm on plant roots, fixes nitrogen, and produces a substance that makes the plant roots more resistant to other pathogens.
Soil and decomposing organic matter aren't necessarily oxygen poor environments, and in ideal conditions they aren't at all. Depending on factors like soil porosity, and rate/frequency of precipitation, there can actually be quite a lot of gas mechanically exchanged between the soil and the atmosphere (water fills up soil pore spaces and pushes out air, then water drains out of soil pore spaces, pulling air back in). Plant roots can respire atmospheric gases into soil as well. Part of the reason why compacted (ie minimal pore space) soil is harder to grow in than the same soil made friable, is because the lack of porosity causes the soil to go anaerobic, which is inhospitable to a lot of beneficial soil microorganisms.
My guess is they say that because that's a much as they can say with full evidence backing. But suspect that most ecologists actually want to say "planting tree is a dumb solution for carbon sequestering or anything, please stop". That's what my ecologists say, certainly.
I mean, consider:
A) Trees are very good at spreading themselves. A tree adapted to it's environment will spread everywhere.
B) You can't get more carbon into an environment than ecosystem naturally sequesters - what it sequesters in long term, what's at the end of forest succession [1]. I'm in the California Sierras now and a lot of areas have a higher density of trees than the long term average and this along with global warming has contributed to the massive summer fires we've had. If anything, what this area's ecology needs is a thinning of the stick-like trees that have grown over the last 100 since all the existing trees were cut down during the Gold Rush. That can happen through fire or through human intervention but since human intervention is costly, fire is what it will be - fires made worse by fire suppression over many years. California's ecology is "fire based", etc.
> “Industrial hemp absorbs between 8 to 15 tonnes of CO2 per hectare (3 to 6 tonnes per acre) of cultivation.”
> Comparatively, forests capture 2 to 6 tonnes of carbon per hectare (0.8 to 2.4 tonnes per acre), depending on the region, number of years of growth, type of trees and other factors, Shah said.
> Shah, who studies engineered wood, bamboo, natural fiber composites and hemp [at Cambridge, UK], said hemp “offers an incredible scope to grow a better future” while producing fewer emissions than conventional crops and more usable fibers per hectare than forestry.
"Cities of the future may be built with algae-grown limestone" (2022) https://www.colorado.edu/today/2022/06/23/cities-future-may-... :
> And limestone isn’t the only product microalgae can create: microalgae’s lipids, proteins, sugars and carbohydrates can be used to produce biofuels, food and cosmetics, meaning these microalgae could also be a source of other, more expensive co-products—helping to offset the costs of limestone production.
Carbon sequestration: https://en.wikipedia.org/wiki/Carbon_sequestration
What you need is tonnes of carbon per hectare per year.
We don't have enough space to let these plants be there, we need to convert them into coal and throw it back into the mines.
Biochar is a great soil amendment, and doesn't oxidize over decades or even centuries, depending. Putting it back in the mines is an option, if we ever need to stop rebuilding topsoil, which is itself getting urgent.
Bioenergy with carbon capture and storage (BECCS) > Biomass feedstocks doesn't have a pivot table of conversion efficiencies?: https://en.wikipedia.org/wiki/Bioenergy_with_carbon_capture_... :
> Biomass sources used in BECCS include agricultural residues & waste, forestry residue & waste, industrial & municipal wastes, and energy crops specifically grown for use as fuel. Current BECCS projects capture CO2 from ethanol bio-refinery plants and municipal solid waste (MSW) recycling center.
> A variety of challenges must be faced to ensure that biomass-based carbon capture is feasible and carbon neutral. Biomass stocks require availability of water and fertilizer inputs, which themselves exist at a nexus of environmental challenges in terms of resource disruption, conflict, and fertilizer runoff.
If you keep taking hemp off a field without leaving some down, you'll probably need fertilizer (see: KNF, JADAM,) and/or soil amendments to be able to rotate something else through; though it's true that hemp grows without fertilizer.
> A second major challenge is logistical: bulky biomass products require transportation to geographical features that enable sequestration. [27]
Or more local facilities
We need to be putting carbon back into the ground where we got it, or at least converting into forms where it lives a long time on the surface (decades or centuries).
This is why hempcrete is ideal. But hemp, by comparison, doesn't result in a root-bound tree farm for wind break and erosion control; hemp can be left down to return nutrients to the soil or for soil remediation as it's a very absorbent plant (that draws e.g. heavy metals out of soil and into the plant)
> Hemp can be left down to return nutrients to the soil or for soil remediation as it's a very absorbent plant (that draws e.g. heavy metals out of soil and into the plant)
It won't remove heavy metals from the soil if you leave it there. You also can't turn it into a product if you leave it there.
Alternatively, convert kelp to biofuel and biodegradable plastic, reducing need for both CO2-intensive industries
Building soil organic matter does result in some amount of carbon remaining in the soil, and has the added benefit of increasing the productivity of the land. I imagine a phased approach where the first effort is to increase soil organic matter on a large scale, and then transition to using some of that improved soil to grow a second phase (maybe, trees, maybe hemp, maybe something else) to capture even more. It seems to me that widespread improvement of soil organic matter is the lower hanging fruit, so to speak.
> Comparatively, forests capture 2 to 6 tonnes of carbon per hectare (0.8 to 2.4 tonnes per acre), depending on the region, number of years of growth, type of trees and other factors, Shah said.
Per hectare PER YEAR. Trees can store much much more carbon per hectare.
There are potential unknown negative side effects of reducing environmental plant residues from current levels, however, so the choice of feedstock biomass shouldn't be taken lightly. Perhaps it should be made from human waste streams or fast growing grasses from areas that have high regeneration potential.
Then again, agriculture itself has fundamentally modified ecosystems for centuries, so there's not much that is timeless or sacred about the current state of industrial agricultural land. If it's a question of whether the leftover crop matter rots and CO2 is released, or is captured long term in biochar, then its compelling to consider it.
The logistics of a wetland restoration are that you get a lump of money to get a group to go out and stick plants in the ground, but the problem is that in an intact habitat plants compliment each other. Some won't grow next to tall plants, others will only grow next to tall plants. So a restoration should ideally be a series of planting events over three or four years, but that's either not 'sexy' enough for the financial and public policy people, or doesn't have the sense of closure they're chasing.
Mass tree plantings aren't fundamentally different, and doing mass anything means disturbing the soil. The current wisdom is that there's a point of no return with soil compaction, where if you cross it, there are only two solutions: One is to raise the surface area of the soil to increase the distance, the other is is to wait for the next ice age to scrape it all up and precipitate it back out. Those compaction layers also affect the flow of groundwater, so building upward only solves part of your problem. And it's heavy work, so you're again tromping the ecosystem you're trying to save.
The moral of the story is that if you disturb an area and end up with 90% dead trees, you may have done more harm than good.
It started raining, again, a couple weeks ago: my lawn is a lush, bright green, native surface (with Butterflies, again!); the rest of the street is gray mush.
As I see it, Geological CO2 storage (CCS) may be the only large-scale practical way going forward, despite all the bad rap it gets due to its historical association with the fossile fuel industry. After all, the excess C in the system came from the ground, and the ground may be the only place able to re-absorb it without significant environmental consequences.
Feasible is a different issue.
It is hugely expensive (give CO2 escape velocity) and wasteful (CO2 is a valuable substance, containing 2 important elements).
Green house gas is such a hard problem because it's a dispersed problem. This is where we need to stop removing plant life from the earth, and start seriously considering a little bit of CRISPR to tweak plants to grow fast and absorb as much co2 as possible. It'd also be great if we started iron seeding the southern ocean to kick that ecosystem into gear as we really need evertying to start sequestering carbon.
- they either require space (forests or whatever)
- are hard to produce in sufficient numbers (materials, production capabilities)
- are expensive to run (like energy input, maintenance), in particular don't generate new red balls while removing them.
- disposal cost (where the machine becomes the carbon, like trees, cutting them down and doing something with that)
Once we got it out, on a "pile of carbon", the problem becomes much easier.
There's also
Do we Need Nuclear Energy to Stop Climate Change? - https://youtu.be/EhAemz1v7dQ
Is It Too Late To Stop Climate Change? Well, it's Complicated. - https://youtu.be/wbR-5mHI6bo
(background on C3 vs C4 plants) https://ripe.illinois.edu/blog/difference-between-c3-and-c4-...
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3075750/
https://www.frontiersin.org/articles/10.3389/fpls.2021.71539...
https://innovativegenomics.org/projects/improving-photosynth...
https://www.nationalgeographic.com/environment/article/can-w...
We should consider taking a collective pause to think things through. Our extensive technology use is pushing ecosystems out of balance at planet scale. Perhaps the solution is NOT more technology, with inherently unknown longterm consequences.
It might be in the wrong place (atmosphere) but we definitely want it on the earth, not in outer space.
The earth is currently losing 3kg/s hydrogen and 50g/s of helium because that's what is in the upper atmosphere where a molecule can gain sufficient velocity to escape the orbit.
The issue with CO2 is that it is a heavier gas and so takes more energy to escape and is also more likely to fall. Left on its own over a sufficiently long time period, you'll end up with an atmosphere that is mostly rarefied carbon dioxide (see Mars).
Ejecting CO2 from ground level to the upper atmosphere and beyond in the quantities that are talked about when dealing with carbon sequestration (tons - not kilograms or grams) would be very energy intensive and using current technologies (we don't have surplus non-carbon based energy) would mean that we are adding to the total amount of carbon instead of reducing it.
3kg/s is 95kt/year. The United States emits about 4,900,000kt/year of CO2.
Just wanted to get those rates on the same scale.
It's not really historical as in far in the past. The relatively recent bill pushed by Trump that gives massive tax credits for CO2 sequestration were a veiled subsidy(or whatever you wish to call it) towards extracting more oil with enhanced oil recovery.
From an environmental perspective, CO2 sequestration for EOR (enhanced oil recovery) makes little sense, other than reducing the carbon footprint of production a bit, demonstrating the storage principle and further developing key technology.
What makes more sense is to use geological storage for CO2 captured from industrial processes other than power generation - production of cement, steel and chemicals, in other words processes that would release large amounts of CO2 even if switching 100% to renewable energy.
Also, we need some place to store all that CO2 that purportedly would be captured using DAC (direct air capture) in the future.
In 2020 "the Lionshead Fire [...] have almost completely engulfed the largest forest dedicated to sequestering carbon dioxide in the state [of Oregon]". Turns out that Nature may also decide to destroy a forest. Biomass comes and goes. As you stated, geostorage is the only solution that makes sense from a first principles perspective.
https://grist.org/climate/this-oregon-forest-was-supposed-to...
Yes and no; if we're talking about logging for lumber then it's really a question of efficiency. Logging in optimal ways helps you minimize carbon release and maximize wood production long-term. If most of the wood is used in construction the carbon remains captured so long as the building stands or the timber is re-used or eventually buried, i.e. scrap wood from a tear-down or remodel isn't burned or left near enough to the surface to rot.
Setting aside land for logging this way has the benefit of using economic activity to our advantage. There are obviously limits but there is no one magic solution to climate change.
When people say this they typically mean the land is no longer usable for another purpose. I don't think this is the case with 'forests,' let alone adding more trees to empty spaces in currently populated areas.
> may be the only large-scale practical way going forward
Why must it be "large-scale?" "We could plant trees, in addition to implementing many other common sense measures and improvements collectively." "Yes, but is it web-scale?"
The only reason to do this is to create a large for profit industry driven solely by monopoly granting regulatory bodies as opposed to many individual markets driven by reasonable and non-discriminatory laws and enforcement.
It's "slow sequestration" but it lasts a long time. Hardwood is very valuable, and growing more valuable, and trees are pretty.
Everything else might sequester the carbon faster, but a tree is "forever."
And you wouldn't just plant trees on that piece of land. You could interplant other sequestration for probably 15 years before it was no longer viable, or raise livestock, whatever.
You need to plant a variety of native species keeping track of keystone species and year round food production so that your forest supports other life.
The reality of atmospheric carbon is that we have to get rid of it or face mass extinction. Trying to build some nostalgic idea of a untouched ecosystem in tune with 'nature' is just a feelgood ideology.
We're actually faced with an engineering project - the first planet that our species will terraform.
Whenever I hear about planting trees for "carbon sequestration", I immediately remember walking through that forest and thinking how quiet and dead it felt.
The great simplification of the forest into a "one-commodity machine" was precisely the step that allowed German forestry science to become a rigorous technical and commercial discipline that could be codified and taught. A condition of its rigor was that it severely bracketed, or assumed to be constant, all variables except those bearing directly on the yield of the selected species and on the cost of growing and extracting them. As we shall see with urban planning, revolutionary theory, collectivization, and rural resettlement, a whole world lying "outside the brackets" returned to haunt this technical vision.
In the German case, the negative biological and ultimately commercial consequences of the stripped-down forest became painfully obvious only after the second rotation of conifers had been planted. "It took about one century for them [the negative consequences] to show up clearly. Many of the pure stands grew excellently in the first generation but already showed an amazing retrogression in the second generation. The reason for this is a very complex one and only a simplified explanation can be given.... Then the whole nutrient cycle got out of order and eventually was nearly stopped.... Anyway, the drop of one or two site classes [used for grading the quality of timber] during two or three generations of pure spruce is a well known and frequently observed fact. This represents a production loss of 20 to 30 percent."
A new term, Waldsterben (forest death), entered the German vocabulary to describe the worst cases. An exceptionally complex process involving soil building, nutrient uptake, and symbiotic relations among fungi, insects, mammals, and flora--which were, and still are, not entirely understood--was apparently disrupted, with serious consequences. Most of these consequences can be traced to the radical simplicity of the scientific forest.
https://archive.nytimes.com/www.nytimes.com/books/first/s/sc...
Azn link for HN Books: https://www.amazon.com/Seeing-like-State-Certain-Condition/d...
Random example: blue jays plant oak trees. They like acorns, pick them off trees and bury them for later, and forget some. If you have an ecosystem that supports blue jays your forest will expand without fundraisers and government programs.
Ecosystems fix carbon in more active biomass than just tree trunks. If you get soil building ecosystems and ecosystems that put more carbon in living creatures, you have less carbon in the atmosphere. The extra CO2 in the atmosphere is like fertilizer, and you can get life to utilize it more and grab more of it out of the atmosphere by supporting it in small ways so it can go on to support itself.
I disagree. We also want to avoid ecological cascade effects in our ecosystems.
And perhaps the best way to create a sustainable ecosystem around the trees is to plant them and see what else develops, rather than try and curate a specific balance of organisms.
Geoff Lawton and Sepp Holzer are good people to look into.
Burning 1kg wood releases 1.65 - 1.8 kg of CO2. [0]
Burning 1kg of crude oil releases 3.16 kg of CO2. [1][2]
I would have expected the carbon density of oil to be much higher! To me, this suggests that a very naïve approach of growing trees and storing them in the places where we obtained the oil would be a hypothetically feasible way of significantly reducing the CO2 content in the air. And that is before the wood has been turned into charcoal etc. What am I missing?
[0] https://www.kaltimber.com/blog/2017/6/19/how-much-co2-is-sto... [1] https://www.epa.gov/energy/greenhouse-gases-equivalencies-ca... [2] https://energyeducation.ca/encyclopedia/Barrels_of_oil_equiv...
Wood is valuable and other plant material is similar carbon/kg, so the low-hanging fruit is to take agricultural waste (currently burned or left to rot) and bury it. Hauling all that straw around burns a lot of fuel, so it’s not clear how well it scales compared to other approaches.
Which would, as in the case with 'cut and bury trees' deplete the soil of non-carbon nutrients. There's a reason farmers leave that waste 'to rot'.
You're comparing by weight, so density (which is mass/volume) isn't a part of it. 1kg of wood will take up more space than 1kg of oil. So the density is higher but equal weights of 'mostly hydro-carbon' will release equal amounts of CO2.
[0] https://www.engineeringtoolbox.com/wood-density-d_40.html [1] https://www.transmountain.com/about-petroleum-liquids
"quitting smoking is not always an effective way of avoiding cancer"
"walking in nature is not always effective in preventing heart attack"
"quitting gambling is not always an effective way of avoiding bankruptcy"
X is harmful if you go out of your way to do X in the most harmful way. How insightful! /s
'Oceans take up carbon dioxide through photosynthesis by plant-like organisms (phytoplankton), as well as by simple chemistry: carbon dioxide dissolves in water. It reacts with seawater, creating carbonic acid. Carbonic acid releases hydrogen ions, which combine with carbonate in seawater to form bicarbonate, a form of carbon that doesn’t escape the ocean easily'.
We need to be doing more to enhance the performance of the half of the planet that is covered by water and which is the primary source of carbon dioxide processing imo
Maybe a GMO kind of tree that just grows fast? I've read that it's the young trees that capture a lot of CO2.
I guess one could imagine large areas dedicated for this kind of operation, but it's really difficult to know if it would really be effective, and those plants could become invasive.
The best solution is still to stop using cars and airplanes, ban plastics, force companies to make durable and repairable products, degrowing the economy and enforce sobriety everywhere.
I know most americans refuse to listen to de-growth, but they need to change their mind quickly.
We should pay the logging companies to save a certain number of trees instead of cutting them every 30 or so years.
I wonder if a 1000 year old tree would gather more or less carbon over it's lifetime than 20 separate 50 year old trees?
https://www.nps.gov/articles/000/wildfires-kill-unprecedente...
Additionally at least in my region whenever I leave a plot of land unattended for a few years - tree appear on it. If you leave it for more than a decade it becomes a forest.
So - it seems the important part is assigning land for forests and not bothering the trees that will grow there. The tree-planting is optional.
In 2008 this was a grass field, we made campfires there. Now it's a forest: https://goo.gl/maps/rSeprtz7orYAwVPY8
In fact if you don't mow a lawn for a few months saplings start appearing :) Forests are perfectly good at spreading by themselves, they evolved for millions of years to do that. If you want more trees you just need to let them grow.
However planting new forests in forested areas, and harvesting trees periodically to encourage new growth is a great idea
The ocean is 70% of the planet’s surface and, I think, is where a lot of the work should go on.
Interesting, why? Plankton != dumping, right? Could there be contained plankton "farms" that are similar to fish farms?
[0]: https://www.scientificamerican.com/article/iron-dumping-ocea...
https://www.imf.org/en/Publications/fandd/issues/2019/12/nat...
> When it comes to saving the planet, one whale is worth thousands of trees.
> Marine biologists have recently discovered that whales—especially the great whales—play a significant role in capturing carbon from the atmosphere.
> In recent years, scientists have discovered that whales have a multiplier effect of increasing phytoplankton production wherever they go. How? It turns out that whales’ waste products contain exactly the substances—notably iron and nitrogen—phytoplankton need to grow.
If there's one use-case for civilian small-scale nuclear reactors in trasport, it's behemoth cargo ships. And yes, I get how complicating a matter that is in the short-term. Here's hoping one day (soon-ish) we can make hugely contained fail-safe reactors that don't act as a high prize for trrrsts and such... .
Definitely.
But we should probably focus on stopping the major contributors of atmospheric carbon and greenhouse gasses. The idea that planting trees or saving whales will help us now is unrealistic. We'd make a huge dent if we double-timed replacing fossil fuel energy producers with clean energy production, whether geothermal, solar, wind, nuclear, or a little bit of everything, whatever. Then we should replace the entire global bunker oil burning shipping fleet. Then we should figure out how to replace or manufacture concrete cleanly, then glass. We should be using pure ethanol for air travel, how hard could it be to invent a clean airliner? Then we should regulate the meat industry into the ground, and figure out how to do agriculture cleanly without contributing to the problem. All ICE should be phased out within a decade. And we should do all these things with a mind towards global cooperation; if we want to remove a major contributor in a foreign country like China or South Africa or Turkey or Texas, we should be investing there in kind towards clean energy.
Most of all we need to sacrifice, even the damn libertarians. We are energy and travel and consumer hogs. Every new structure should generate its own power, everything else converted into doing so. If everything was off-grid and clean, the petroleum and coal energy industry would vanish. 90% of what we need should be produced locally. We need to stop the clearing of forests and natural ecosystems for more urban sprawl that everyone hates.
It is ridiculous how the elephants in the room are being ignored. If we'd just usher them out, it would be a lot easier on everyone and the planet.
or at least that is was Neal Stephenson wrote in his latest book. (fiction is always great for scientific knowledge)
As long as you can keep the houses from catching fire. I do admit we have a lot of new knowledge and technologyy that radically improves fire security
Here's a detailed article on the technique https://cbmjournal.biomedcentral.com/articles/10.1186/1750-0...
There were periods in the geological timeline where photosynthesis >> respiration and the result was massive accumulation of coal and oil deposits, such as the during the Carboniferous era (~350 million years ago).
Of course there are many good reasons to do reforestation - prevention of erosion, a supply of timber, habitat for wildlife, retention of water, etc. Offsetting fossil fuel emissions is not one of those reasons.
[edit: on medium length (10K year) timescales, there is an effect of storage of photosynthesis products, one that's involved in the past ~2 million year ice age cycle (with periods of around 100K years). There are two processes: storage of photosynthetic products in the deep ocean, related to decreased circulation, and storage in permafrost, related to growth of permanent ice, that slowly decrease atmospheric CO2 during the descent into ice ages.]
The only way to sequester carbon is to make something like limestone (Ca/Mg + CO2 + H2O -> (Ca/Mg)CO3) and that requires calcium or magnesium ions. There are some sources of those ions, but not that many. Another option is production of something like carbon fiber material, or even better, blocks of diamond.
Photosynthesis is not the most efficient process in the equation by far. It is competing against two things; a system that can use lots of oxygen as an oxidizer to release energy, and titanic stockpiles of hydrocarbons waiting to be burned. An animal can either consume plants after they've done their job or consume other animals, and use animated lungs to consume a constant stream of oxygen that can be used to oxidize the energy substrate. Plants can only use photosynthesis, which is much less efficient of an energy transfer than respiration (creating molecules instead of breaking them apart). Because plants are stuck with photosynthesis as a food source, they are limited by its speed. Plants still need oxygen to respirate the food they create for themselves, but they cannot afford lungs and a cardiovascular system to utilize more oxygen. If they could, then they might as well be eating other organisms that already performed the hard work for them.
What I'm saying is that humans, being respiration animals, are always competing with plants, and do even more so when they release carbon from reserves in the earth. The ability of artificially propagated plants to compete against that system is minuscule. It can only compete with surface area, and for humans to be able to even make a dent in atmospheric CO2 by planting trees would mean planting way more trees than is likely worth their own expended energy. In such a scenario, the tables are flipped, and the animals (humans) are competing against the inefficiency of photosynthesis and must use enough energy to compensate. That is neither a proven strategy nor sustainable. Just as body fat can in theory be lost entirely through exercise, it is orders of magnitude more efficient to simply not introduce more energy into the system (i.e. consume less food, and eat food with fewer if any deleterious side effects).
So yes we can't operate as we do and fix it by on the side planting a few trees.
However I can’t find a link to the actual study in the article.
Has there ever been a study that linked the increase in CO2 to the increased logging efforts in places around the world?