4 ms·

I wonder if petrifying trees after they absorbed CO2 would help our emissions problems?

vkou 8y ago
Yes, it would. But if you are turning trees into coal, and burying them, why on Earth are you also digging up coal, to burn it? Sequestration is going to be far more work then simply not generating emissions in the first place.
- maerF0x0 8y ago
  Tell me if this is incorrect thinking: An advantage of sequestration is location. Something like you can emit the CO2 in a distributed manner (think car tail pipes) and then sequester it nearby but in aggregate (think a facility just outside city limits)
  - vkou 8y ago
    The problem is that, in a market economy, like the one we live in, we can dig up and burn coal much faster then we can grow and bury trees. Coal can be mined for $30/tonne. That's 3 cents/kilogram. At that price point, it's nearly free. How can you keep up with sequesteration, when you are competing with nearly-free? Sequestration makes sense when we are talking about an economy that derives ~5-10% of its energy from liquid fossil fuels, and everything else from renewables. It doesn't make much sense when 50% of energy generation comes from fossil fuels. It's just too labour intensive to make it work.
    - int_19h 8y ago
      Not just a market economy - a market economy that does not account for externalities, like carbon emissions in the atmosphere.
- benchaney 8y ago
  We need to do both in order to prevent a civilization ending catastrophe. Sequestration has the advantage of allowing our net carbon output to be negative. Obviously getting to zero is the first goal, but we are already past the point where that would be enough.
- loeg 8y ago
  > why on Earth are you also digging up coal, to burn it? That is a good question regardless.
deleted 8y ago
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throwaway5752 8y ago
If you could do that in a net energy negative way that would be something.
- deleted 8y ago
  [deleted]
saalweachter 8y ago
No; petrified wood is the same as other fossils: it is minerals, such as silica, which has filled in the void in the earth left after the organic material has decayed. You can still bury the wood in an environment that does not allow it to (quickly) decay, or you can simply make a lot of stuff out of wood. (If you go the second route, you'll want to ensure that your wood structures last a long time, you'll want to increase the total wood sitting around in the world, and once you reach a new plateau in the amount of wood products in semi-permanent existence, you'll stop sequestering new CO2 via the process of consumerism, new products and structures will just be re-sequestering the carbon lost from old structures and products as they decay or are destroyed.)
- int_19h 8y ago
  How long they decay wouldn't matter that much if you have the disposal process. The amount you'd end up processing every year would still be the same (reflecting total usage at any given isntant) once you get past the initial ramp-up.
  - saalweachter 8y ago
    The duration is important because you can only grow and harvest a finite amount of wood each year, because trees can only grow so fast. So if you harvest the maximum amount of wood possible each year, W, and it lasts for 10 years, you have sequestered 10 x W units of carbon; if you use it in ways that lasts 20 years before it needs to be replaced, you have sequestered 20 x W units of carbon.
papercrane 8y ago
Yes, one of the proposed sequestering techniques is to produce and sequester biochar, essentially charcoal produced from biomass.
opwieurposiu 8y ago
In the Carboniferous period[2], plants evolved lignin which made their cell walls stronger so they could grow taller. Fungi that could eat lignin had not evolved yet and so the the dead trees just built up layer after layer. This build up eventually turned into the coal we mine today. Turning trees into charcoal[1] is one way to slow down the processes of the wood turning back into CO2, but it would be difficult to do it on a large enough scale. https://en.wikipedia.org/wiki/Biochar https://en.wikipedia.org/wiki/Biochar https://en.wikipedia.org/wiki/Carboniferous https://en.wikipedia.org/wiki/Carboniferous

vkou 8y ago

Yes, it would. But if you are turning trees into coal, and burying them, why on Earth are you also digging up coal, to burn it? Sequestration is going to be far more work then simply not generating emissions in the first place.

maerF0x0 8y ago
Tell me if this is incorrect thinking: An advantage of sequestration is location. Something like you can emit the CO2 in a distributed manner (think car tail pipes) and then sequester it nearby but in aggregate (think a facility just outside city limits)
- vkou 8y ago
  The problem is that, in a market economy, like the one we live in, we can dig up and burn coal much faster then we can grow and bury trees. Coal can be mined for $30/tonne. That's 3 cents/kilogram. At that price point, it's nearly free. How can you keep up with sequesteration, when you are competing with nearly-free? Sequestration makes sense when we are talking about an economy that derives ~5-10% of its energy from liquid fossil fuels, and everything else from renewables. It doesn't make much sense when 50% of energy generation comes from fossil fuels. It's just too labour intensive to make it work.
  - int_19h 8y ago
    Not just a market economy - a market economy that does not account for externalities, like carbon emissions in the atmosphere.
benchaney 8y ago
We need to do both in order to prevent a civilization ending catastrophe. Sequestration has the advantage of allowing our net carbon output to be negative. Obviously getting to zero is the first goal, but we are already past the point where that would be enough.
loeg 8y ago
> why on Earth are you also digging up coal, to burn it? That is a good question regardless.

deleted 8y ago

[deleted]

throwaway5752 8y ago

If you could do that in a net energy negative way that would be something.

deleted 8y ago
[deleted]

saalweachter 8y ago

No; petrified wood is the same as other fossils: it is minerals, such as silica, which has filled in the void in the earth left after the organic material has decayed. You can still bury the wood in an environment that does not allow it to (quickly) decay, or you can simply make a lot of stuff out of wood. (If you go the second route, you'll want to ensure that your wood structures last a long time, you'll want to increase the total wood sitting around in the world, and once you reach a new plateau in the amount of wood products in semi-permanent existence, you'll stop sequestering new CO2 via the process of consumerism, new products and structures will just be re-sequestering the carbon lost from old structures and products as they decay or are destroyed.)

int_19h 8y ago
How long they decay wouldn't matter that much if you have the disposal process. The amount you'd end up processing every year would still be the same (reflecting total usage at any given isntant) once you get past the initial ramp-up.
- saalweachter 8y ago
  The duration is important because you can only grow and harvest a finite amount of wood each year, because trees can only grow so fast. So if you harvest the maximum amount of wood possible each year, W, and it lasts for 10 years, you have sequestered 10 x W units of carbon; if you use it in ways that lasts 20 years before it needs to be replaced, you have sequestered 20 x W units of carbon.

papercrane 8y ago

Yes, one of the proposed sequestering techniques is to produce and sequester biochar, essentially charcoal produced from biomass.

opwieurposiu 8y ago

In the Carboniferous period[2], plants evolved lignin which made their cell walls stronger so they could grow taller. Fungi that could eat lignin had not evolved yet and so the the dead trees just built up layer after layer. This build up eventually turned into the coal we mine today. Turning trees into charcoal[1] is one way to slow down the processes of the wood turning back into CO2, but it would be difficult to do it on a large enough scale. https://en.wikipedia.org/wiki/Biochar https://en.wikipedia.org/wiki/Biochar https://en.wikipedia.org/wiki/Carboniferous https://en.wikipedia.org/wiki/Carboniferous