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Every time one of these articles come up I wonder about the price per tonne of CO2 removed by simply growing wood and not burning it. I'm not really sure what t
by 6nf 8y ago
Every time one of these articles come up I wonder about the price per tonne of CO2 removed by simply growing wood and not burning it. I'm not really sure what that price is, but it seems to be around $20-$40 per tonne? Does anyone have a more accurate number?
- FrojoS 8y agoFor comparison. A ton of CO2 is roughly the equivalent of a London-NYC roundtrip in the economy class. https://calculator.carbonfootprint.com/calculator.aspx?tab=3 https://calculator.carbonfootprint.com/calculator.aspx?tab=3
- dithering 8y agoThere's got to be something that grows faster, and is easier to sequestrate, than trees. Bamboo, maybe? Seaweed? Algae? Dry it off in salt pans and dump it in the deep, cold ocean? That's just dumping more carbon into one of our natural sinks, I think, rather than trying to create a new artificial sink. Even just using it as fertilizer has got to be an improvement over using inorganic fertilizers.
- Gustomaximus 8y agoIron fertilization https://en.wikipedia.org/wiki/Iron_fertilization https://en.wikipedia.org/wiki/Iron_fertilization
- czbond 8y agoThank you for posting this - the link is very interesting.
- majos 8y agoCool idea, I'd never heard of this. TL-DR is that there are huge portions of the ocean that are nutrient-rich but have little life, and one hypothesis is that iron is the limiting factor here. Since various phytoplankton need iron to survive, why not dump iron in these places, watch the phytoplankton now thrive, and enjoy their carbon sequestration? The answer seems to be "well, we don't really know what the effect would be". Some algae blooms are not good (red tide), deliberately altering an ecosystem is generally dangerous, it's not clear whether the positive local effect on carbon has some side effect elsewhere (maybe we're just moving phytoplankton around the ocean). Even doing experiments on this is difficult (the world's oceans are weirdly regulated), and current financial incentives don't make it all that enticing either. But a cool idea.
- ValleyOfTheMtns 8y agoI think all these comments about wood eventually releasing the carbon back into the atmosphere are missing the point. We don't need to capture it forever, we just need to get the ratio between carbon output and input under control in the next couple of decades. That should give us enough time to come up with longer term and sustainable ways of our planet... until we encounter the next problem, and so on. "Solutions" don't have to be perfect forever. They just need to work long enough till better solutions are discovered.
- village-idiot 8y agoYou could also just bury it. That’s effectively putting coal back into the ground.
- thinkcontext 8y agoWood is not dense enough for this to be cost effective.
- adwn 8y agoYou could burn it – the ash from burning a tree takes up only a fraction of the original volume.
- sudhirj 8y agoDon’t know if this is sarcasm, but burning the wood releases most of the carbon dioxide back into the air. The ash is just the unburnt carbon residue and other leftovers.
- adwn 8y agoYes, it was a joke. Sorry for that.
- logfromblammo 8y ago
- Symmetry 8y agoWell, according to Energy and Civilization forest stores an average of 1 watt per square meter in burnable wood. Wood burning is pretty carbon intensive as energy goes so I imagine that each square meter of forest, if the fallen trees are buried deep underground, could offset several watts of internal combustion engine use.
- 08-15 8y agoNope. The energy density of gasoline and wood per carbon atom is about the same. So a watt is a watt, and forest are inefficient (about 0.4%) at converting sunlight into chemical energy.
- thinkcontext 8y agoCarbon in trees is still part of the carbon cycle, it will eventually be released again though it may be buffered for a time. That's merely neutral as opposed to negative that you get with sequestration.
- Cthulhu_ 8y agoTrue, and the current CO2 problem is exactly because of that eventual release - it's just that the CO2 was locked in oil and coal from millions of years ago. Growing trees would work, but only as long as their decomposition can be stopped (like it did when coal formed) or at least limited so that not all their CO2 is released and a big part of it returns into the ground. But, major tree growing operations are already being done, lots of companies are into the CO2 trading business where growing trees = an X amount of CO2 emission rights they can sell to CO2 producing companies / factories.
- Udik 8y agoA 1 hectare (10k m^2) poplar plantation yields 30 tons of wet biomass per year; average carbon content of wet wood is 15-20%; that would translate into 4.5 tons of co2 sequestered per year (assuming that all the carbon comes from the atmosphere). To offset 5GT of carbon dioxide emissions per year, you'd need 110 million hectares, or 1.1 million square km, that is 13 times the surface of Kansas. Then of course every year you'd have to cut down something like 1/7th of the trees, throw them in a big hole, and replant them. Just about doable, I'd say. :)
- dwighttk 8y agoRotting wood releases carbon dioxide too.
- erikpukinskis 8y agoYou don’t let it rot. You mill it, and scorch it. That will give you a couple hundred years of protection. Then you start stacking the timbers in a pyramid. As you add more and more layers to the pyramid, the bottom layers compress, eventually becoming totally uninhabitable by bugs and bacteria. Over time you end up with a giant pyramid made of coal, and possibly diamond. (haven’t done the math on how tall you have to stack coal to get diamond)
- dwighttk 8y agothis is starting to sound like minecraft
- deleted 8y ago[deleted]
- ovi256 8y agoIf the purpose is carbon sequestration, you'll have to include the cost of storing that wood. Indefinitely. Won't be cheap.
- rbanffy 8y agoWe can bury it until it becomes oil again.
- torpfactory 8y agoDoesn’t a forest tie up the carbon in live trees? A mature forest will be more or less carbon neural but a certain amount of carbon won’t be available to the atmosphere.
- ForHackernews 8y agoThe trees will die eventually. The problem is that we've released a lot of CO2 from trees that died millions of years ago.[0] If you want to get that out of the atmosphere, it's not good enough to grow trees today because in 50-100 years (or whenever a tree dies) you're right back where we are today. [0] https://www.nationalgeographic.com/science/phenomena/2016/01/07/the-fantastically-strange-origin-of-most-coal-on-earth/ https://www.nationalgeographic.com/science/phenomena/2016/01...
- gascan 8y agoThe tree which dies is replaced by a new tree. You're right that we've added more carbon than can be stored in living forests. But reversing deforestation can & should be part of the solution.
- FartyMcFarter 8y agoYou'll also need to store it in a way that does not release the wood's CO2 back to the atmosphere by biodegradation.
- rbanffy 8y ago
- hodgesrm 8y agoTaking your estimated numbers it's interesting to add that cost to the price of fuel and see where it gets you. A gallon of gasoline on average produces about 20 pounds of C02, so 100 gallons gives a ton of CO2. You can then calculate the cost of adding capture to gas prices. * At $200 per ton gas prices increase $2 per gallon. * At $100 the increase is $1 per gallon. * At $40 the increase is $0.40. * At $20 the increase is $0.20. It looks as if we need to get numbers into the low tens of dollars for this to be feasible on a widespread basis. The numbers are optimistic since they don't cover the CO2 from refining and transport. That seems to be around $2 but it's somewhat hard to get accurate values.
- 6nf 8y agoYea that's what I mean. It seems that cheap fast growing timber can be purchased for $20 per tonne. Dry timber is about 50% carbon and CO2 is about 30% carbon, so that means we can grow CO2 out of the atmosphere at a price of around $12 a tonne. We'll need to stack the wood somewhere but I don't think that will be terribly expensive.
- hodgesrm 8y agoThe problem we're seeing in the US West is that wood has an increasing tendency to burn up. For this to work at least where I live we need to reforest using species that grow fast and are also relatively fire-resistant. It seems people have been thinking of the fire-resistant part for a while: http://blog.davey.com/2017/08/fireproof-landscapes-with-fire-resistant-plants-trees-and-shrubs/ http://blog.davey.com/2017/08/fireproof-landscapes-with-fire....
- throwaway5752 8y agoIf only they had a soft cap and let people trade credits to try to keep emissions under that cap to incentivize sequestration and efficiency innovations.
- 08-15 8y agoYou know what's the problem with that idea? There are no "sequestration and efficiency innovations". Sequestration doesn't work and takes too much energy, and efficiency cannot be improved much thanks to thermodynamics. Besides, if the IPCC is correct about how bad CO2 is, the only sensible cap for emissions is zero. You don't get there with tiny improvements in efficiency.
- throwaway5752 8y agoI'm sarcastically saying that we had proposals for a cap and trade system that would have mitigated it but it was destroyed for political reasons.
- 08-15 8y agoObviously. I'm non-sarcastically saying that cap-and-trade won't work, because any meaningful cap is unrealistic to achieve. The political reason is: We want cheap energy. The politically acceptable choices boil down to burning coal or gas, no matter how bureaucracy is layered on top.
- deleted 8y ago[deleted]
- ph0rque 8y ago~$6 per (short) ton ($0.10 per tree planted, which removes ~34 lbs of carbon per year). More here: http://shindyapin.tumblr.com/post/141034501197/climate-change-solution-simplified http://shindyapin.tumblr.com/post/141034501197/climate-chang...
- sambeau 8y agoI've often wondered (half jokingly) if a solution to CO2 in the atmosphere is to grow trees, chop them down and bury them in disused coal mines.