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Restoring natural forests is the best way to remove atmospheric carbon

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Re: Restoring natural forests is the best way to remove atmospheric carbon

#81

Post by EGreg »

usrusr wrote: post #62
dahfizz wrote: post #43

Earlier quoted context omitted.

With absolutely no expertise in the subject, I would expect any sufficiently large land area to have no net oxygen production. It's not like oxygen levels fluctuate wildly, and it seems unlikely to have such a uniform O2 level on Earth if it's coming from just a few big producers.

Basic chemistry: the only ecosystems that can continually produce net O2 are those that permanently stash unoxidated C away (aka new fuel). This was the norm A Very Long Time Ago when plants were briefly ahead in the chemical arms race against everything that lives off decaying plant matter (and thus caused an imbalance which created the chemical energy we now use as fossil fuels). But in more recent history (e.g. an…

What about the other way, producing CO2?

Re: Restoring natural forests is the best way to remove atmospheric carbon

#82

Post by jfoucher »

timClicks wrote: post #75
ph0rque wrote: post #63

Earlier quoted context omitted.

Actually, if the trees are burned or otherwise re-release their carbon, the subsequent re-planting will take care of re-re-capturing that carbon. If any of the trees die or are cut down, a new one can be planted in its place. If it still living and thriving, it should be naturally left alone. Also, for ten years, 327 million Americans each planting 1.5k trees comes out to half a trillion trees. The link in my blog sa…

When the trees die, won't the carbon be re-introduced to the atmosphere over time via microbial decomposition of the wood? That is, once the microbes that eat the trees die, they'll be eaten by something that is eventually eaten by something on the surface, thus releasing the carbon sequestered by the tree.

Not if a new starts growing in place of the old one. The carbon is sequestered in the mass of the living trees so that is what counts

Re: Restoring natural forests is the best way to remove atmospheric carbon

#83

Post by usrusr »

EGreg wrote: post #81
usrusr wrote: post #62

Earlier quoted context omitted.

Basic chemistry: the only ecosystems that can continually produce net O2 are those that permanently stash unoxidated C away (aka new fuel). This was the norm A Very Long Time Ago when plants were briefly ahead in the chemical arms race against everything that lives off decaying plant matter (and thus caused an imbalance which created the chemical energy we now use as fossil fuels). But in more recent history (e.g. an…

What about the other way, producing CO2?

When the ecosystem is somehow tapping into an ancient stockpile of high energy C compounds to oxidate, sure, it will release more CO2 than it consumes. An example of such an ecosystem would be humans doing agriculture boosted with the Haber-Bosch process, which oxidates fossil fuel to capture plant nutrients from the air (even our crops are not entirely solar powered).

Chemistry is incredibly simple when you are only interested in the general inputs and outputs of a black box system.

Re: Restoring natural forests is the best way to remove atmospheric carbon

#84

Post by xyzzyz »

dragonsky67 wrote: post #78
timClicks wrote: post #75

Earlier quoted context omitted.

When the trees die, won't the carbon be re-introduced to the atmosphere over time via microbial decomposition of the wood? That is, once the microbes that eat the trees die, they'll be eaten by something that is eventually eaten by something on the surface, thus releasing the carbon sequestered by the tree.

How about we turn them into houses or furniture. Timber used in construction can last for a very long time, all the while keeping it's carbon locked up. Even when it finally decomposes through rot or consumption a lot of the carbon is kept out of the atmosphere, ending up in the food chain fed by the organisms that consume it. Plant a tree now, in 200 years it may be part of your great great great grandchildren.

Even when it finally decomposes through rot or consumption a lot of the carbon is kept out of the atmosphere, ending up in the food chain fed by the organisms that consume it.

No, not a lot. In fact, it’s practically nothing, compared to the mass of trees. Think about it: are you using the mass of 150 adult trees annually for buildings? Are you sequestering much of it in your body? Not even close. Today America consumes less than a half of a single adult tree per capita per year.

The carbon is only sequestered when the trees are alive or when they are buried or sunk. If you don’t bury and only have space for a decade of tree planting, you are at best going to delay the climate change by a decade, which is not nothing, but won’t change much. And, of course, we ignore things like albedo changes due to more forestation which could offset a big part of gain.

Re: Restoring natural forests is the best way to remove atmospheric carbon

#85

Post by xyzzyz »

ph0rque wrote: post #76
timClicks wrote: post #75

Earlier quoted context omitted.

When the trees die, won't the carbon be re-introduced to the atmosphere over time via microbial decomposition of the wood? That is, once the microbes that eat the trees die, they'll be eaten by something that is eventually eaten by something on the surface, thus releasing the carbon sequestered by the tree.

Yes, that could happen. Replacing the dead tree with a seedling will re-capture that carbon and return to a net-zero atmospheric carbon balance. Also, there are many situations where a net-negative amount of carbon could be released into the atmosphere: the tree could be used as lumber to build something, thus not decomposing. Or it could be partially or fully buried, sequestering some or most of the carbon in the so…

Using it as lumber will only extend the time period when the carbon is sequestered, but won’t sequester it permanently. You need to bury it for that, and bury it deep enough so that it doesn’t decompose.

More importantly, the actual lumber consumption is trivial. America consumes half of a single tree per capita annually[1]. Even if you assume that this half of a single tree gets sequestered permanently (which is not realistic), that’s a far, far cry from 150 trees yearly.

Really, this is all so silly: if you can grow so much biomass to offset all carbon emissions, why wouldn’t you burn that biomass instead of burning fossils and burying the biomass? It makes no sense, like most of the feel-good green plans.

[1] - https://www.fs.usda.gov/treesearch/pubs/50895

Re: Restoring natural forests is the best way to remove atmospheric carbon

#86

Post by akimball »

ph0rque wrote: post #63
xyzzyz wrote: post #61

Earlier quoted context omitted.

So, to offset his carbon emissions, American must plant 150 trees a year, ensure that they grow for at least 10 years, and then ensure that the CO2 captured by them doesn’t get rereleased. This means that we need space for at least 3 trillion trees, which is three times the space available, based on the figure in your link. Ensuring that the CO2 doesn’t get rereleased means that all that lumber needs to be buried or…

Actually, if the trees are burned or otherwise re-release their carbon, the subsequent re-planting will take care of re-re-capturing that carbon. If any of the trees die or are cut down, a new one can be planted in its place. If it still living and thriving, it should be naturally left alone. Also, for ten years, 327 million Americans each planting 1.5k trees comes out to half a trillion trees. The link in my blog sa…

There are twenty times that many people on Earth. You would have to compactify the wood for building materials, or something similar, to properly sequester. I suggest iron seeding the equatorial pacific as cheaper and more scalable.

Re: Restoring natural forests is the best way to remove atmospheric carbon

#87

Post by LifeLiverTransp »

The problem is- that in poor countries, forrest are chopped down faster then you can rebuilt them. So what you need is a mixture of reforrestation- the natural forrest in diffiult to reach regions. And "crop" forrest - aka bamboo in those regions that will get pillaged.

Re: Restoring natural forests is the best way to remove atmospheric carbon

#88

Post by ph0rque »

xyzzyz wrote: post #85
ph0rque wrote: post #76

Earlier quoted context omitted.

Yes, that could happen. Replacing the dead tree with a seedling will re-capture that carbon and return to a net-zero atmospheric carbon balance. Also, there are many situations where a net-negative amount of carbon could be released into the atmosphere: the tree could be used as lumber to build something, thus not decomposing. Or it could be partially or fully buried, sequestering some or most of the carbon in the so…

Using it as lumber will only extend the time period when the carbon is sequestered, but won’t sequester it permanently. You need to bury it for that, and bury it deep enough so that it doesn’t decompose. More importantly, the actual lumber consumption is trivial. America consumes half of a single tree per capita annually[1]. Even if you assume that this half of a single tree gets sequestered permanently (which is not…

Why are you fixated on permanently sequestering the carbon? As soon as a tree dies, all you need to do is replace it by replanting the tree. It doesn't matter if the tree's carbon is immediately released in the atmosphere (by burning) or it happens after hundreds of years. The new tree will re-sequester the dead tree's carbon.

Also, if a tree dies, it frees up space for another tree. So in effect, as long as you keep those 1.2T trees growing (and replace any dead ones promptly), you will keep that carbon sequestered.

> Really, this is all so silly... It makes no sense, like most of the feel-good green plans.

At this point, it seems like you're just dismissing the idea. Feel free to do so, but you haven't provided any reason why it won't work.

Re: Restoring natural forests is the best way to remove atmospheric carbon

#89

Post by dragonwriter »

ph0rque wrote: post #88
xyzzyz wrote: post #85

Earlier quoted context omitted.

Using it as lumber will only extend the time period when the carbon is sequestered, but won’t sequester it permanently. You need to bury it for that, and bury it deep enough so that it doesn’t decompose. More importantly, the actual lumber consumption is trivial. America consumes half of a single tree per capita annually[1]. Even if you assume that this half of a single tree gets sequestered permanently (which is not…

Why are you fixated on permanently sequestering the carbon? As soon as a tree dies, all you need to do is replace it by replanting the tree. It doesn't matter if the tree's carbon is immediately released in the atmosphere (by burning) or it happens after hundreds of years. The new tree will re-sequester the dead tree's carbon. Also, if a tree dies, it frees up space for another tree. So in effect, as long as you keep…

> Why are you fixated on permanently sequestering the carbon? As soon as a tree dies, all you need to do is replace it by replanting the tree.

This is true on average in otherwise equivalent conditions, sure.

Re: Restoring natural forests is the best way to remove atmospheric carbon

#90

Post by ph0rque »

akimball wrote: post #86
ph0rque wrote: post #63

Earlier quoted context omitted.

Actually, if the trees are burned or otherwise re-release their carbon, the subsequent re-planting will take care of re-re-capturing that carbon. If any of the trees die or are cut down, a new one can be planted in its place. If it still living and thriving, it should be naturally left alone. Also, for ten years, 327 million Americans each planting 1.5k trees comes out to half a trillion trees. The link in my blog sa…

There are twenty times that many people on Earth. You would have to compactify the wood for building materials, or something similar, to properly sequester. I suggest iron seeding the equatorial pacific as cheaper and more scalable.

Americans produce a disproportionate amount of CO2 due to their lifestyle. So you don't need to plant twenty times that amount of trees to sequester manmade CO2; only 2.4x.

Also, as long as you replace any trees that die with seedlings, you don't need to worry about what happens to the dead wood.

This method comes out to a cost of $6.70/ton sequestered. Other methods can cost many multiples of this amount. Do you have any estimates for iron seeding of the equatorial Pacific?

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