No one is saying don't plant trees. Fuck yeah, plant all the trees! But that won't wont be enough. Sequestration will get better, but one of the big things it helps with is locality. CO2 isn't homogenously spread across the globe. It also doesn't spread very well. Concentrations vary drastically over the year and so do plants' ability to capture carbon. Carbon can build up in certain regions. Worse, it can pool where we can't grow trees [0]. Places where we can't get enough water to introduce new populations of trees (without significant carbon costs, defeating the purpose. Also the local ecosystem) Cities. The Arctic. The ocean. I'm all for planting trees (even beyond CO2, I just feel better around trees) but people need to stop making the trees vs sequestration argument. It's trees + sequestration (air and ocean) + promoting corral development + more. (This same argument applies to a lot of things, especially in climate. It's not a "this vs that" argument, it's "this PLUS that".
Sequestration is also good for catching carbon at potential emission sources; it's easier to grab CO2 out of the atmosphere at the point where you're burning methane than to let it out in the atmosphere and then try to catch it again.
(Or, in some interesting experiments, even before emission; there's work on splitting methane from natural gas into carbon and hydrogen and just burning the hydrogen. Gets you something like 66% of the energy of burning the methane completely, and with no CO2 emissions.)
Re: your second point, splitting methane into H2 and CO2 is not something that's being investigated at lab scale, it's how 95% of global hydrogen production today is done. We're talking close to a trillion cubic meters per year from steam methane reforming.
It's just that most of the time, resulting CO2 is just released instead of being stored. But that is changing, fast.
I was specifically referring to pyrolysis, where unlike steam reforming no oxygen is introduced and so the carbon comes out as solid graphite. Scaling the process, and running it in a continuous-operation reactor, is still an area of active engineering work (see e.g. https://pdfs.semanticscholar.org/d36a/ff0a2db0f99a92c2debd5b...), mostly focused on designing the physical system so that the solid carbon comes out nicely during the reaction instead of gunking up the works.
What are the benefits of pyrolysis versus steam methane reforming (SMR)? My immediate thought would be that you leave energy on the table, and that storage at scale is harder when the end result is graphite. Moreover, SMR is proven technology at very large scale.
One advantage is that it produces high-purity graphite, which is a moderately expensive commodity, used for electronics manufacturing (especially power components in batteries), structural carbon composites, and machine lubricants.
The percentage of carbon captured is also damn near 100% - quite a bit better than gaseous carbon capture techniques I've heard of.
You do leave quite a lot of energy on the table (losing somewhere between 30% and 50%), so this is a technology that is only economically viable with high emissions pricing. But that seems like the way Europe is going anyway.
And yes, SMR is the proven and clearly superior technology right now; I'd call this TRL 4/5 right now. But with another decade of development?
Aha, so it's targeting "CCU". Then OK, I can maybe see there is a point initially, but not at anything near the scale we need.
Global graphite production from mining is at 1 megatonne/year, while synthetic is a few hundred kilotonnes/year. We need CCS to operate at tens of gigatonnes per year, that's four orders of magnitude beyond all the graphite the world needs.
This is the problem with anything CCU - there just aren't viable options with consumption at the gigatonne scale.
At the gigatonne scale, nothing is easy to store. Fill the entire Hoover dam with graphite, and you've stored 6 gigatonnes. We need to store tens of gigatonnes per year for a hundred years.
Trees will actually do the trick. I looked for an international business that would plant a 1000 trees for me which would offset my entire carbon footprint for my entire life. Didn't find anything except a local one in Iceland [1] in Icelandic only (good luck with Google Translate).
I can offset my footprint for 800$/year and I think it's going to be my New Years resolution. No more carbon from me.
Finding land and planning trees for it should be a global business. There are a lot of people like me with disposable income that would invest in something like that.
Please also include a resolution to reduce your carbon emissions.
Remember that planting trees only work if you have the guarantee that in the future these trees will not be burned. Also, some natural decomposition also emits CO2
Planting trees can delay/slow down climate change. What happens in a decade when planting trees does not scale anymore and we've kept increasing our emissions in the same time?
I am about 50 years old. Planting trees scales for at least 50 years. Something on the order of 1000 trees will offset the entire footprint of a upper-middle class non-jetsetter (eats meat, travels 2-4 times per year, car, modest house).
There are a lot of technology promises on the horizon that will hopefully solve the next inflection point, but that's not my climate crisis, it will be the next generation. Hopefully by then the human race will have developed fusion or other energy technologies.
Next time, could you get a video from someone who's actually seen a tree?
That video was just awful. It's only redeeming feature was that it was short. Here's what he got wrong:
1. The mass of CO2 in the atmosphere is about 3E+12 tonnes (not tons). Around a third of that is additional from humans, so around 1E+12 (cf trillionthton.org - they were a bit optimistic). That's pretty close to what he had, only out by a factor of 2, but purely by chance (there's a fair bit of that).
2. He rounded down the population, so the figure of 130 tonnes per person is again, pretty close.
3. The 0.33 tonnes per year from just breathing is beyond stupid. Unless you're drinking gasoline and eating coal, then all the CO2 you breathe out came from the atmosphere in the first place. It came from growing plants. This is just lazy and ignorant. It's not like he even uses this figure anyway.
4. Typical per-capita CO2 is not "10-ish tonnes per year" for a developed country. That's the high end. The UK is hardly a shining beacon of green policy, and even it is at 6.5 tonnes per year. What's more, we're trying to improve on that. 5 tonnes per year is closer to what the average person can easily manage without sacrificing anything.
5. Not all CO2 emissions stay in the atmosphere. A large part are absorbed by the oceans (hence ocean acidification). He should know this.
6. Great, now we've got the bizarre rectangular tree. Was the volume of a cylinder too much work to look up? Anyway, it's actually oddly difficult to get the total mass of a tree (not that he tried), because lumber yards tend to only care about the trunk. I found a site that gave a complete measurement of an oak, including canopy and roots. It came out to around 20 tons, around 10 tons dry biomass, giving around 5 tonnes carbon.
7. Carbon. Not CO2. Multiply by 44/12 to get the CO2 required. That's 18 tonnes CO2 per tree. Let's drop that down to 10 and say we have small trees.
8. Wait, what? He didn't even use the volume. He just guessed 1 tonne C02 per tree!
9. When trees die, they leave a gap in the forest and new trees grow. How else would forests last for thousands of years? Once you've planted the trees they will replace themselves. What's more, the wood could be used for building or furniture which means it will retain the CO2 even longer. What's even more, giving ourselves a hundred years or so breathing space while we reduce and reverse emmissions is absolutely worth it.
Huh, I didn't mean to type so much but there was so much wrong with that video that I just kept going.
With you until the last point. When newly planted forests mature, a lost tree is not generally replaced. Trees around the 'gap' grow into the gap and take the sunlight, getting larger in the process.
In this way a stand of small trees becomes a much-less-dense stand of very large mature trees.
Don't know how it affects the analysis - is a mature forest more carbon-dense than a newly-planted one?
Yeah, I did oversimplify that. I guess I was really saying, that if your trees live for 100 years, say, it's not like the whole forest disappears once the 100 years are up.
And, of course, if it's used for forestry, the trees will be continually removed and new ones planted.
No one is saying don't plant trees. Fuck yeah, plant all the trees! But that won't wont be enough. Sequestration will get better, but one of the big things it helps with is locality. CO2 isn't homogenously spread across the globe. It also doesn't spread very well. Concentrations vary drastically over the year and so do plants' ability to capture carbon. Carbon can build up in certain regions. Worse, it can pool where we can't grow trees [0]. Places where we can't get enough water to introduce new populations of trees (without significant carbon costs, defeating the purpose. Also the local ecosystem) Cities. The Arctic. The ocean. I'm all for planting trees (even beyond CO2, I just feel better around trees) but people need to stop making the trees vs sequestration argument. It's trees + sequestration (air and ocean) + promoting corral development + more. (This same argument applies to a lot of things, especially in climate. It's not a "this vs that" argument, it's "this PLUS that".
[0] https://youtu.be/x1SgmFa0r04