Trees and plants are net consumers of CO2 when they grow, but become neutral when they reach maturity, so they are more of a carbon buffer. The buffer can be freed when they burn or rot, both of which happen naturally.
The best way to permanently take away CO2 from the atmosphere is to cut off the trees and somehow store them where the CO2 cannot escape (and to free space for new trees to grow). Some of the carbon from dead plants is stored in the soils, but this takes a lot of time to do.
In the long run biofuels + carbon capture can be carbon negative.
We already have shortage of building-grade wood, because it needs to be grown for 60-90 years, while today's wood is cut at 30. Younger wood is softer, attracts bugs, rots easily.
Wow! so much scientific conversation and not one thought about gazillion of animals who live in those trees. Did you guys know earth was doing pretty fine with just trees and animals before all these tech, or even their talk, appeared in the scene.
> The best way to permanently take away CO2 from the atmosphere is to cut off the trees and somehow store them where the CO2 cannot escape
I really don't understand this logic. The oil industry spends billions every year to extract oil (= fossilized biomass) buried deep underground, because burning biomass gives you cheap energy.
If you cut down and store enough trees to compensate for the current CO2 emissions, you will have access to an immense volume of biomass, much easier to "extract" than oil is.
What do you think is going to happen with this biomass? People are going to burn it to make cheap energy again..
Actually, why would you even go through the trouble of cutting down the trees in the first place? You could just, not extract the oil and end up with the exact same amount of energy you will have at the end of this complex process.
One way to to store that carbon by burning the trees is and storing the CO2 underground - it will be costly to extract and worthless to do so and you will get some energy out of it.
Doesn't burying the trees drastically increase the length of capture? Then it's a matter of cost and resource optimisation. I'd do the job of planting, cutting, trucking, and burying trees with pride.
You joke, but if you have a solid idea of how to permanently¹ sequester carbon from trees in a cheap and scalable fashion, it might be worth submitting that proposal. If nothing else, it can serve as a baseline against which other proposals are judged (as in X tones more cost effective than the "plant some trees" approach).
¹ Some uses for wood, like as fuel, release the carbon back into the atmosphere. Likewise anything where the wood decomposes.
A tree is actually a very poor method of carbon capture. It's not durable and doesn't last ages. It can catch fire. And it takes decades. If you're gonna do organic methods then blue-green algae is way better. But I think the idea here is to come up with a technology that's even better than that.
When CO2 is pumped underground, the high pressure makes carbonic acid in any moisture which reacts with calcium to make calcium carbonate. In the ocean, marine life catalyze this reaction to make skeletons, shells, and coral. In shallow bodies of water, the organic material gets mixed in and packed under this lime and sand, and becomes oil and gas. In swamps, plant material gets packed under itself until it becomes coal, and yes, some of it escapes as gas. On dry land carbon fixation is very complicated with many life forms, mostly insects which have skeletons too, but actually the big carbon fixer is fire. There isn’t enough oxygen in a massive fire to oxidize all of the carbon, so you end up with reactions that create large amounts of carbon charcoal and water vapor. Charcoal is biologically useless, so it is fixed, but the minerals in the ash are great fertilizer.
Life on earth has been doing this for about 3 billion years now, regardless of us, because the earth is constantly burping up huge amounts of carbon in volcanic eruptions (in addition to great mineral fertilizer). Could we do it better? Maybe, but probably not. I think if you look into any of the new technologies for this, the total carbon cost of production and operation is far far greater than the amount sequestered. I doubt it will ever reach significantly greater carbon:carbon efficiency than nature. There may be something to gain by speeding up the natural processes, but almost certainly more by simply reducing negative interference.
this is less about earth and the green tech, and more about mars, as his reply to EverydayAstronaut's query about the viability of the Sabatier process hints:
> It’s a good path for fully renewable rocket energy, so solves part of problem, but longer chain hydrocarbons than CH4 are needed to be solid at room temp
This also links up with spacex not only buying two oil rigs to turn into starship platforms abut also buying a gas well for in house methane production
Of course Mr. Musk wants to hype up the impact of carbon emissions....Tesla Motors wouldn't turn a profit without the ability to sell ZEV regulatory credits to other automakers.
If Mr. Musk really cared about carbon dioxide in the atmosphere, he wouldn't fire rockets around up there every few days.
Not flying those rockets will have no effect. A single launch puts out about as much CO2 as a single full transatlantic flight. Consider how many of those fly every single day, let alone the shorter flights.
Setting aside other pollutants in rocket soot (of which there are many) and only looking at CO2:
Which rocket are you saying produces that much CO2, and where did you get that convenient number? Falcon 9 weighs like half a million kg. Falcon Heavy is about three times that. Starship will weigh like 5 million kg. I hope you're not under the impression that all rockets uniformly produce the same emissions. It depends on a few different factors.
Falcon 9 burns RP-1 kerosene, and uses twice as much of that fuel as Soyuz.
Falcon Heavy burns 440 tons of RP-1 kerosene. A 747-8i can carry 60,755 gallons of jet fuel (similar distillate), weighing 407 thousand lbs, or 203 tons. Its range at maximum take-off weight is 9,210mi. A flight from Boston to Glasgow is about 3k miles, so that's three transatlantic flights per tank, or 6.5 transatlantic flights per Falcon Heavy flight.
I wonder if Mr. Musk would support forcing spaceflight companies to offset their carbon emissions by paying for reforestation. Somehow, I doubt it.
Furthermore, rocket emissions deliver gases directly to the middle and upper atmosphere, so their pollution is more impactful pound-for-pound than aircraft emissions.
And in fact, Mr. Musk wants to replace air travel with rocket travel. Check out this SpaceX video from 2017. It's not just one or two flights we're talking about. He wants to fly thousands. https://www.youtube.com/watch?v=zqE-ultsWt0
These are all fair points and I'm going just off quick Googling. But here's what I found regarding the Falcon 9 [1][2] which puts it around 425 Metric Tons per flight. And for a fully loaded airliner there are CO2 emission numbers per seat which can put it up in the 500 Metric Ton range [3] for a long flight. Our numbers are not that far apart. 3 flights vs 1 flight is a rounding error in the scale of global CO2 emissions.
The Starship numbers are much harder to analyze though, it entirely depends on how you get the methane, because yes, it will put out a LOT more CO2 per flight. Methane can be collected from the production of coal/natural gas/oil where it is burned anyway, or as SpaceX has said they would like to do, from the Sabatier process which would actually be carbon neutral given that you can produce Methane by extracting CO2 from the atmosphere.
I can't deny that it will spread the CO2 further through the atmosphere even if it is carbon neutral, but when it comes down to it, rocket launches are now and for the foreseeable future a minuscule portion of CO2 output and airplanes, cars, and industry are all orders of magnitude greater emitters.
And then when it comes to Musk, it just seems weird to say he isn't doing enough to combat CO2 on a post about him donating $100M to help improve CO2 removal and also ignore what electrification of cars can and already has done for CO2 emission reduction.
I think my math is fairly reasonable for a back-of-the-envelope calculation and I also note that we both acknowledge that we're within an order of magnitude of one another. However, we have pretty accurate information about airliner fuel consumption, and one transatlantic flight is just not the same as a single Falcon flight. That's a fact.
> And then when it comes to Musk, it just seems weird to say he isn't doing enough to combat CO2 on a post about him donating $100M to help improve CO2 removal and also ignore what electrification of cars can and already has done for CO2 emission reduction.
Forget Mr. Musk for a second. If Philip Morris reports 7.5B of revenue alongside a widely publicized anti-smoking campaign, are you going to give them a pat on the back or are you going to say that good PR can be an intentional distraction from the tangible externalities of profit-seeking activity?
Now, back to Mr. Musk, a man who runs one business whose profit depends entirely on government market controls, and another business that depends largely on government contracts. When Trump was president, Mr. Musk decried COVID lockdowns as un-Constitutional. However, now Biden is president and Mr. Musk is pushing a few dollars (relative to his vast fortune) toward a green initiative.
In that context, and given the fact that petroleum-powered flight on the scale publicly suggested by Mr. Musk's future plans would definitely produce a nontrivial amount of pollution, we shouldn't be so quick to herald Mr. Musk as some kind of druidic entrepreneur who loves Earth so much that he wants to make a second one on Mars.
Someone else accused me of having strife with my family rather than interpreting my comments as a good-faith dissent from widespread adulation of Mr. Musk's ostensible benevolence. I don't think that would have happened if I had expressed skepticism about Big Tobacco instead of Big Rocket.
EDIT: Methane from Starship is particularly problematic because, if leaked, it is so much more damaging to the atmosphere than CO2. This is part of the reason that venting natural gas from wells unequipped to capture it is a huge no-no. I agree that evaluating emissions from Starship is a bit more challenging.
I'm going to assume you aren't trying to be disingenuous.
First off, the kerosene rockets are going to be replaced with methane ones so that will greatly reduce the carbon output.
Secondly, he has stated many times that once they're flying regularly they'll be creating methane fuel themselves from carbon capture.
Additionally, you have to expel mass to build a rocket. That's a requirement. You can do it with no carbon with hydrogen-oxygen rockets, but hydrogen has a lot of issues with it. Also much as people like to talk about hydrogen being green, the vast majority of all current Hydrogen is from methane steam reforming and has quite the carbon footprint.
> I'm going to assume you aren't trying to be disingenuous.
If you truly make that assumption, why start by casting aspersions on my sincerity?
> First off, the kerosene rockets are going to be replaced with methane ones so that will greatly reduce the carbon output.
Mr. Musk envisions hundreds of flights of methane-powered rockets with immense payload capacity in the thousands of tons. Methane combustion produces CO2. A Starship flight will put more CO2 into the air than a Falcon Heavy flight. Its advantages are likely to be less NOx and less soot.
> Secondly, he has stated many times that once they're flying regularly they'll be creating methane fuel themselves from carbon capture.
This barely exists in a laboratory yet, let alone at the scale needed for retail spaceflight. Ask yourself, where do we get methane these days? Answer: Largely from fracking and as a byproduct to other fossil fuel harvesting/processing.
> Additionally, you have to expel mass to build a rocket. That's a requirement. You can do it with no carbon with hydrogen-oxygen rockets, but hydrogen has a lot of issues with it. Also much as people like to talk about hydrogen being green, the vast majority of all current Hydrogen is from methane steam reforming and has quite the carbon footprint.
Now you're starting to see my point. Someone who is focused only on creating green technologies wouldn't put his solvency on the line to build and grow a fossil-fuel-based space propulsion company. Space flight is critical to the future of mankind, but we have to be clear-eyed about its ramifications and avoid greenwashing it for the benefit of corporations. $100m sounds like a lot of money until you compare it to Mr. Musk's net worth.
Replace people with people in general, and reread - maybe you don't qualify, maybe you do - people's self-awareness and ability to orient is pretty bad in general too when it comes to health. However you've done nothing to prove your point other than taking what I said literally and taking offense to it, instead of arguing the point as to if my point has merit or not.
You're making assumptions that I don't see there will be environmental impact - it can however be offset and I believe rockets to get things into space is an area where we'll have to accept and compromise - at least until if a space elevator becomes possible.
> Replace people with people in general, and reread - maybe you don't qualify, maybe you do - people's self-awareness and ability to orient is pretty bad in general too when it comes to health. However you've done nothing to prove your point other than taking what I said literally and taking offense to it, instead of arguing the point as to if my point has merit or not.
A) You're clearly not writing nor addressing anything in this thread that is germane to carbon capture, spaceflight, Mr. Musk, or any other aspect of the article.
B) The simple fact that you're talking about me and my relationship to my peers and family is evidence that you have focused the conversation on the qualities of a speaker rather than the merits of his speech. Please re-evaluate the thread and see how you arrived at this juncture.
