Posted by PaulHoule 5 days ago
If that fraction isn't negligible, we'd be better off burning it. Determining that fraction, across a range of conditions, is nontrivial.
It's the same logic for construction materials. A house has dozens of trees worth of lumber in it, and that carbon is now trapped in the house for however many decades it takes until the house eventually burns down or rots. Meanwhile the trees that were cut regrew, so the total "inventory" of trapped carbon has increased. (Appreciating of course that the lifetime carbon cost of the emissions required to maintain and climate-control a house will far exceed the modest value of what is trapped in its walls, but all of this is just for the sake of argument.)
There's a bit of nuance to be filled out, like challenges of forest plantation monoculture and so on, but it always sounded quite practical to me. Iirc the idea derived from "coal".
Basically any place where you've got high timber production within a reasonably short distance of an arid area could make for a relatively low-tech sequestration/storage pipeline.
I grew up in an area known for coal and logging. Ever since I heard of sequestration brought up I thought the area sounded perfect for it. Fell (maybe mulch) the trees, kiln dry to remove weight/moisture, and toss them down a mineshaft.
It always felt a bit peotic to 'reseed' a coal mine
Maybe it would be more effective to drop wet lumber off in the desert for a few years by rail before moving the dry lumber to permanent underground storage. This assumes two stages of transport to and from the desert would cost less carbon than transport to a kiln and then to storage.
I’m not convinced that the wood even needs to be dried before burying, though.
2. Store spent fuel in massive wooden dry caskets. (500-1000x steel)
3a. Float caskets to Antarctica
3b. Offload via rail to South Pole
4. They stay frozen for a million years and don't rot. Problem solved.
Edit: I think I've thought of a good alternative though. Instead of crating up the nuclear waste, it could be randomly dispersed in forests around the world to scare people away from those forests, thereby creating nature reserves which should last for generations.
With saltwater it's a bit trickier because it's decently oxygenated even to depth and there is a lot of life dedicated to breaking down wood in the ocean. If you can get it to sink into the muck it lasts a lot longer though.