> unless you can plant a very large number of trees which live to maturity
and what, then? When plants die, their matter is decomposed by fungi and all their carbon is released back into the atmosphere (unless the dead plant matter is buried).
The act of planting trees, in itself, is carbon neutral. Not good, not bad, just irrelevant to the presence of carbon: the carbon is still in the cycle of life within the biosphere.
To reverse the burning of fossil fuels, all that new carbon that we introduced into the biosphere needs to be buried back to where it came from. For example, by cutting trees and burying their wood in sealed mines several kilometers underground.
> The act of planting trees, in itself, is carbon neutral. Not good, not bad, just irrelevant to the presence of carbon: the carbon is still in the cycle of life within the biosphere.
Isn't this a little like saying that humans in a confined space don't actually use up any of the oxygen, because it's still technically present in the CO2 they exhale?
> For example, by cutting trees and burying their wood in sealed mines several kilometers underground.
What would be the net benefit of treating it like radioactive waste versus using it as a construction material? Yes, a small percentage of the carbon would escape, but most of it would stay locked up in the wood, and one wouldn't create the massive amounts of CO2 necessary to build and operate those hypothetical mines.
> What would be the net benefit of treating it like radioactive waste versus using it as a construction material?
Man, that was just a silly example to illustrate the absurdity of the situation. We are currently unearthing millions of years worth of sequestered carbon per year and dumping it all into the atmosphere. Talking about planting trees is ridiculous at this point. Like pumping water out of the sinking titanic with a champagne glass. If we don't want to increase the amount of carbon in the atmosphere we just need to stop putting it in!
You seem to be assuming that the carbon will stay locked in the construction materials. But I doubt that it will, what will happen to it after the building is destroyed ? Either it will have been by fire, or as waste, will likely be back in the atmosphere after wood-eating life is done with it.
I wonder how feasible it would be to put wood (from particularly dense species ?) on the bottom of the expanding anoxic ocean zones ? That seems to be one of the rare locations where the only thing that could possibly degrade it are sulphur-"breathing" bacteria, which seem to have trouble digesting lignin ?
But even here, it might still be easier to just stop burning fossil fuels ? EDIT : ninjaed
P.S.: For an opposite example, see how concrete reabsorbs over decades back up to half of the CO2 exhaled during its production.
P.P.S.: Supposedly, soil-buried charcoal is also decently stable, I guess even fungi find it unpalatable ??
The thing is humans build more and more. Any destruction or burning is replaced with more building. So in that sense construction with wood has aligned incentives and is more economical than just burying carbon with is purely a cost. But construction seems unlikely to be sufficient alone. Tho most of the world prefers concrete which is also releases carbon iirc so them switching to wood may help.
> and what, then? When plants die, their matter is decomposed by fungi and all their carbon is released back into the atmosphere (unless the dead plant matter is buried).
Why does every measure have to solve the problem? Buying time is just as important. We start mammoth groves now. Buy time for measures that solve the problem and win huge ressources (building wood, recreational space, erosion prevention) for the future.
It's not "Mammoth groves" if you want to meaningfully "buy time". A grove is an open tree stand a few acres wide. That's not what we're talking about. It's not adding a little bit of tree seed to unused spaces. It's inverting our footprint entirely.
It's planting the entirety of the UK, every year, indefinitely. It's employing a few million people with heavy machinery to walk from one side of the planet to the other and bulldoze every farmhouse they find, leaving behind mixed saplings at a wide spacing in the fields.
It's just way easier to decarbonize most of our society than it is to spend the land on forest carbon fixation. It's a lot of land, more land than we'd ever agree to dedicate.
And I would point out that planting trees and then sequestering that carbon periodically with charcoal production is by far the easiest way. Every other technique is ten or a hundred or a thousand times lower payoff.
If you want to slow things down, you have to mostly stop burning fossil fuels. We need to tax the hell out of them, we need to shut down new projects, we need to electrify anything feasible, we need to heavily subsidize and aggressively plan for rapidly scaling renewables. When we're at a 90% reduction in fossil fuel usage, then we can re-assess priorities because we've both "bought some time" and eliminated all the low-hanging fruit that's easier than deliberate carbon fixation projects.
More likely, we'll keep on steamrolling ahead, and something like sulfur geoengineering will be put forward as a way to stave off the worst effects for a while.
I suppose we could do that too, down the line, if we plant trees now.
It's at least a method of buying time, but maybe not so reliable. It presumes no one will find a way to cut them down for profit later. So maybe we'd need to add each tree planted to a growing count of trees "never to be cut" in the country.
All the work involved in felling, cutting and manually sequestering the wood sounds like it could be more expensive - and a lot slower and less scalable - than direct air capture. (Which is already uneconomical)
and what, then? When plants die, their matter is decomposed by fungi and all their carbon is released back into the atmosphere (unless the dead plant matter is buried).
The act of planting trees, in itself, is carbon neutral. Not good, not bad, just irrelevant to the presence of carbon: the carbon is still in the cycle of life within the biosphere.
To reverse the burning of fossil fuels, all that new carbon that we introduced into the biosphere needs to be buried back to where it came from. For example, by cutting trees and burying their wood in sealed mines several kilometers underground.