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Planting trees not always an effective way of binding carbon dioxide

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Re: Planting trees not always an effective way of binding carbon dioxide

#81

Post by xenadu02 »

Klapaucius wrote: post #16

Sequestring CO2 is a huge scale problem, and all solutions have significant flaws. Forests require vasts amounts of land, and storage is only assured as long as nobody decides to chop down the forest for other more pressing purposes (looking at you, Brazil). Storing CO2 in oceans (either in the form of "ocean fertilization" or by directly dissolving CO2 in seawater) could have huge and unknown consequences for marine…

> storage is only assured as long as nobody decides to chop down the forest for other more pressing purposes

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.

Re: Planting trees not always an effective way of binding carbon dioxide

#82

Post by simple10 »

vkou wrote: post #76
simple10 wrote: post #73

Trees need to be cut and buried to effectively sequester carbon. Here's a detailed article on the technique https://cbmjournal.biomedcentral.com/articles/10.1186/1750-0...

Won't this result in soil depletion, as you bury vital non-carbon nutrients?

Good question. Maybe it depends on how deep they're buried and how far the nutrients leach into the surrounding soil.

Re: Planting trees not always an effective way of binding carbon dioxide

#83

Post by ThinkBeat »

Trees absorb while growing. Reach "max CO2" At which point you need to cut down the trees and plant the next generation. You somehow store the trees so they will not have any risk of releasing the CO2 again.(like if they burn)

or at least that is was Neal Stephenson wrote in his latest book. (fiction is always great for scientific knowledge)

Re: Planting trees not always an effective way of binding carbon dioxide

#84

Post by arbuge »

ThinkBeat wrote: post #83

Trees absorb while growing. Reach "max CO2" At which point you need to cut down the trees and plant the next generation. You somehow store the trees so they will not have any risk of releasing the CO2 again.(like if they burn) or at least that is was Neal Stephenson wrote in his latest book. (fiction is always great for scientific knowledge)

Building with the lumber from them is one way of storing them. Even that is not infinite though, though it could buy you a lot more time until renewables and possibly CCS become more viable.

Re: Planting trees not always an effective way of binding carbon dioxide

#85

Post by orthecreedence »

vanderZwan wrote: post #46
westurner wrote: post #4

"Hemp twice as effective at capturing carbon as trees, UK researcher says" (2021) https://hempindustrydaily.com/hemp-twice-as-effective-at-cap... : > “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 tr…

Do you know of any papers investigating how kelp or other seaweeds compare? I've heard some biologists informally claim that they would be even more effective because they can grow incredibly fast.

I thought trees were somewhat ideal because the carbon sequestered in them can be used as long-lived lumber. If the kelp sequesters carbon but then it gets released immediately when it decomposes or someone eats it, then it doesn't really solve the problem.

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).

Re: Planting trees not always an effective way of binding carbon dioxide

#86

Post by hinkley »

My native plant friend has a rant I've heard twice and I gather he's given countless times.

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.

Re: Planting trees not always an effective way of binding carbon dioxide

#87

Post by photochemsyn »

wikfwikf wrote: post #64
photochemsyn wrote: post #53

Earlier quoted context omitted.

The point is, plant matter is not geologically sequestrated in the present world. The oceans are oxygenated and circulation is pretty strong, and permafrost is decreasing, not increasing. Hence, any photosynthesized carbon material will be returned to the atmosphere as CO2 relatively quickly. The only way to sequester carbon is to make something like limestone (Ca/Mg + CO2 + H2O -> (Ca/Mg)CO3) and that requires calci…

Why can't you just create oil or coal or similar products?

Well, the only reason to do that is to combust those products to create energy, right? If you want to bury the oil or coal as a means of carbon sequestration, well I suppose you could do that with wood instead, but if people really want to stablilize atmospheric CO2, the first step is to stop using fossil fuels entirely.

Re: Planting trees not always an effective way of binding carbon dioxide

#88

Post by shagie »

OJFord wrote: post #78
mountaintimefrm wrote: post #40

So having read the article summary, then the research paper, then reading the article summary again... it seems that the summary isn't at all an accurate summary of the research paper, but rather a narrow focus on the suboptimal cases where tree growing isn't super effective at sequestering carbon. It sort of completely ignores the cases where they observed enhanced carbon sequestration, increases in soil organic car…

Regarding nitrogen fixing, my understanding is that 'green manure' & cover crops take from the air, leave in the soil - but microorganisms sounds like it's more in the context of composting, where whatever waste material is 'broken down'. So not 'soil' in the sense of 'it was already there anyway', but rather.. 'in the ground but needing to be made smaller and more available'.

Cover crops have a symbiotic relationship with nitrogen fixing bacteria that they maintain in their roots. When the crop is harvested (and the roots die), the nitrogen that was fixed by the bacteria in the roots remains in the soil.

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.

Re: Planting trees not always an effective way of binding carbon dioxide

#89

Post by colechristensen »

wikfwikf wrote: post #61
colechristensen wrote: post #2

Yes you need to build ecosystems not just plant trees. Monoculture tree stands are often mostly empty of other life. 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.

Why do you care about the forest supporting other life? Isn't the goal just to take carbon out of the atmosphere?

Ecosystems grow, maintain themselves, and can be better at sequestering carbon.

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.

Re: Planting trees not always an effective way of binding carbon dioxide

#90

Post by monknomo »

wikfwikf wrote: post #61
colechristensen wrote: post #2

Yes you need to build ecosystems not just plant trees. Monoculture tree stands are often mostly empty of other life. 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.

Why do you care about the forest supporting other life? Isn't the goal just to take carbon out of the atmosphere?

The more life a forest supports, generally, the more carbon gets removed and the longer the forest lives.
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