Sucking carbon dioxide out of the sky is moving from science fiction to reality
npr.org
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The answer is that we need to store almost 40B tonnes of CO2, or around 10B tonnes of C if we break that down, every year. That's something on the order of 1500 great pyramids of Giza (which weighs 6M tonnes) worth of carbon every year.
Unless and until emissions are reduced to a tiny minuscule fraction of current ones, carbon capture will not do even one iota to help with global warming.
You're perhaps thinking of how long it took to build more modern mega-buildings like the Empire State Building or Burj Khalifa. But those are much lighter weight than the great pyramid (365k tonnes and 500k tonnes respectively, compared to the 6M tonnes of the great pyramid).
Building even one such pyramid per year would be a huge project for a wealthy industrial state. And there aren't 1500 wealthy industrial states in the world to help with the others.
So yes, building 1500 great pyramids of Giza is actually a low ball estimate. The right image is burying 1500 great pyramids of Giza - which is much harder and more expensive.
[1] https://www.youtube.com/watch?v=azEvfD4C6ow&pp=ygUKYmFnZ2VyI...
In the US, we have over 20% of electricity coming from coal. Any money spent on anything else should first go toward pushing this down to zero.
The intended message, just like for geongnineering, is "keep burning oil, we'll figure it out another way".
Excavation capacity is not the bottleneck here.
Prohibiting fossil fuels seems like a much simper way than trying to somehow let the market regulate that.
While carbon capture can be unilateral.
That's easy for economic blocks like the US and the EU. There's plenty of other regulations they have coerced other nations to follow.
This one machine in Germany is already making the equivalent of ~15 great pyramids per year, by tons of material moved:
https://en.wikipedia.org/wiki/Bagger_288
Carbon capture is difficult currently, but we'd have to problem dispensing with this amount of material per year on a global scale.
I agree there's a separate question, how much air do we need to suck through carbon extraction machines.
Many of the emission neutral DAC models I’ve looked at lose 10% — billions of tons — of their industrial chemistry inputs every year even assuming expansive recycling of the input components to the extent possible. The annual loss greatly exceeds current annual production for all purposes.
The effects on agriculture are far more severe than sea level rise.
Or just slapping the same CO2 sequestering method at the end of industrial chain that creates CO2 rather than trying to catch it later.
Better to resign ourselves to poverty and lower living standards than try to actually solve the problem quickly because it seems hard, right?
I don't see how modern productive agriculture (without which the supportable world population without completely destroying the remaining natural areas of the world goes down to 2-3 billion) would work in a carbon neutral world without using giant solar or wind farms to essentially produce artificial fossil fuels from atmospheric CO2... which sounds like carbon capture tbh.
The ideal here would be for the world's richest countries, whose wealth has been built off of emitting the majority of the CO2 already in the atmosphere, to fund massive green energy projects in countries like China and India. There's no reason why China should be building new coal plants to bring electricity to their population while the already electrified EU and USA twiddle their thumbs and import another hundred million tonnes of plastic doodads.
Industrial Agriculture is responsible for effectively burning off most of the carbon captured in the soil.
Using no-till, regenerative techniques can capture carbon back into the soil, improve water retention, reduce soil temperatures, reduce the need for chemical feedstocks (fertilizer, herbicides, etc.), and simultaneously produce livestock (and their feed), all while producing comparable amounts of crop.
The only increased input required is active local management, which requires downscaling production, but as an upside allows diversifying the nature of crops produced.
Cheap reusable rockets seemed hard until SpaceX came along and made them routine.
Carbon capture is not exactly picking up where the Shuttle left off.
The most interesting part of carbon capture is the offshoot technologies.
We've put too much emphasis on consumption of low-quality goods. We are drowning in shitty stuff.
Getting rid of shitty stuff isn't "lower living standard" or "poverty".
These are examples of systemic waste product that are only useful for consumerism churn. Besides T-Shirts and plastic waste, there are tons of products that are produces with the least concern for long-term usage. Because it not "economic" - only because we allow to externalize all the associated costs.
[0] https://goodfair.com/blogs/nonewthings/did-you-know-that-one...
In the case the original source of the first link is page 10 of this: https://ctprodstorageaccountp.blob.core.windows.net/prod-dru...
The first link has been victim of a game of telephone, where the original source had 15kg per T-Shirt, more than half of that was washing costs, assuming 50 hot washes (and this from over 15 years ago when washing machines were less efficient and electricity much less green). 6kg from T-shirt production being their actual estimate.
Is 6kg "a lot"? Depends what you're comparing it to. Worldwide clothing industry in general seems to be around 1% of total CO2 according to the above link.
I would love it if we had a sensible estimate for what the sum of CO2 externalities is, but my understanding is estimates can differ by over two orders of magnitude.
The sad reality with carbon capture is that it's an excuse to put more carbon into the atmosphere than is actually being captured. The oil and gas companies pump billions into capturing carbon are not interested in efficiencies. They are merely interested in making many billions more on dumping more carbon in the atmosphere. If that ever gets close to what they produce, their cost will be so high that they will be out of business. The goal with this is merely delaying that moment. The cynical bit is of course that they are using lots of government subsidies to pretend to capture tiny amounts of carbon. A significant portion of the IRA (1 trillion $) has been earmarked for, once more, fattening the pockets of oil and gas industry.
All the carbon capture in the world to date doesn't add up to anywhere close to more than absolutely irrelevant token amounts of carbon relative to the amount we're continuing to put into the atmosphere. This amount btw. continues to grow year on year. We've merely slowed the pace at which the increase is growing. That growth is showing signs of maybe starting to decrease very soon. We'll still be putting out a larger amount of carbon every year though. We're decades away from turning that growth into actually net removing carbon. And we'll need to keep that up for centuries before it turns around current trends in global warming.
But stopping the burning of oil and gas, which is now very doable, would be a nice start. That's billions of tonnes per year of co2 that we don't have to remove from the atmosphere. Orders of magnitude more than these companies will ever capture. The best way to capture carbon is to leave it in the ground and not burn it.
https://www.sciencedirect.com/science/article/pii/S254243511...
Fan energy for this scheme is estimated as 61 kWh per tonne of CO2.
So as with all science, consult multiple whitepapers, including ones that don't have direct or borderline not indirect funding from those who have financial incentive to get a result that increases revenue or similar, to get a clearer idea of the probability that the topic isn't incorrect or what have you.
As an aside, whether it's right or wrong (since it's a heated topic), I feel these videos demonstrate at least the possibility of companies playing with these kinds of things. They're amusing to watch, if nothing else, in my opinion: https://youtube.com/watch?v=MondapIjAAM and https://youtube.com/watch?v=EIezuL_doYw
[1] https://www.cheminst.ca/magazine/article/out-of-thin-air/
[2] https://www.theglobeandmail.com/business/article-bcs-carbon-...
I'd appreciate an attempt to actually put some numbers on how much it would cost to pull in a billion billion litres of air, because on the face of it this sounds like it might only cost a trillion dollars in equipment, not counting the giant solar farm required to run it.
Think of the huge investment required to extract fossil fuels and process them into something useful. Now imagine something similarly huge in scale, but the output product, instead of being incredibly valuable, is actually useless.
There’s no free lunch here. You either pay the cost now or you pay it later. Florida is already paying since their homes are quickly becoming uninsurable, and that’s not going to get better.
https://journals.plos.org/plosone/article?id=10.1371/journal...
He says the same thing, with receipts. All these carbon capture things are just fossil fuel companies extending their lifetime. They spend X million on "solving" carbon capture while spending 2*X million telling people how hard they're working on solving carbon capture.
This has been going on for decades with very very minimal progress.
But the fossil fuel companies like to tout how they will increase their carbon capture by 500% by 2030. They do not mention how that increase brings them from 0.01% of their total carbon output to 0.05% in 10 years.
Aren't most of them startups? The point of the article is that this is the first time an oil company is doing it (and they're doing it to inject into fields, not for climate reasons). If Gore is really claiming all carbon capture projects are by oil firms then surely he is lying.
You're probably confusing carbon capture in general (which already exists in some quantities, although still small to what would be meaningful) with DAC. For the latter, Climeworks is kinda the leader, which is an independent startup. But even there, there's also carbon engineering, which is funded and owned by oil corps. (You may still call that a startup in the sense that it's a relatively young company trying something new, but well...)
But for carbon capture in general, all the large players are fossil fuel corps. Equinor in Norway, Shell in Canada, etc., all big oil. The only meaningful player that is not fossil fuel associated is Carbfix in Iceland.
If so, it's the person who posted the Al Gore talk that's confusing it, not the responder who assumed the Gore talk was about DAC, the original post.
IOW, someone did a bait & switch and folks who keep trying to talk about DAC are "confused".
Obviously that means he has no chance in the US.
Naturally it's never described that way. It's typically framed as something like 'we should delegate this task to the private sector because they're more efficient'.
And I suppose my next questions would be:
* "why were those managing the recount so inflexible about when the re-count had to be completed by?"
* "why wasn't there any middle ground that could have been achieved by those (ostensibly) asking for 'openness' and those wanting to do the recount?" --- for example, by this, I am imagining something like the police maintaining order amongst the viewing public, so that they do not physically harm or otherwise distract the re-counting officials, and having professional observers from both parties available to make rounds as the process is being executed?
Just turn each unit over and shake it. (Like a three hole punch.)
Not following procedures. One of the many consequences of conducting elections on the cheap.
So dumb.
The fact that BBR worked is only because those two points were true?
The Supreme Court decided that didn’t matter.
The top comment makes effective carbon capture sound impossible, but to put it in perspective, the Interstate Highway System in the US alone used "enough [aggregates] to make 700 mounds the size of the largest Egyptian pyramids."[1]
If the numbers here are right, carbon capture would be (very) roughly 2x the size of the IHS, compressed into a single year, and repeated every year. An enormous project, but spread out across many willing nations, and perhaps helped by the fact that CO2 diffuses naturally through the atmosphere and doesn't have to be transported like sand and gravel.
Difficult but doable, if the political will existed.
1: https://highways.dot.gov/highway-history/interstate-system/5...
Well forcing ultimately ends in forcing violently, so this seems to be a bit tautological.
We (and other wealthy nations) can directly subsidize the replacement of carbon emitting processes to the extent possible with the agreement not to build more. This won't happen of course, but the idea that the only way forward is to force people is ridiculous.
Right after you just wrote off international cooperation to reduce emissions?
OTOH, reducing emissions demands cooperation from everyone.
The cooperation either happens or it doesn't, but either way carbon capture is significantly less effective than decarbonising.
How should we force China to stop emitting?
India wasn't even in the top 50% 20 years ago -- the nation is developing, they're burning fossil fuels and they're going to keep doing it to bring their people out of poverty. Should they keep their population in poverty?
What about other developing nations? Will Nigeria and Indonesia and Pakistan and Brazil decide that they'd rather keep their populations poor than build fossil fuel plants?
And the US only accounts for about 15% of total emissions.
And note that the solution for reducing emissions in China and India is relatively simple: commit string-free resources and money to building renewable grids and nuclear instead of coal.
Money is fungible. Subsidising Chinese power means subsidising its military. Given it’s presently a dictatorship, that’s a dangerous proposition.
We should focus on decarbonising ourselves. Once our per-capita emissions are lower than others’, we can show them the way.
Regardless, my point was that there are many options besides war for quite directly reducing other cointries' emissions. There may be second order effects, so I'm not necessarily advocating for it, but there is certainly no reason to say "we've done all we can".
That's a good point that is not mentioned enough in these discussions. Basically, we cannot stop other countries from releasing CO2, but we can "steal" their air.
https://www.iea.org/reports/key-world-energy-statistics-2021
IEA Key World Energy Statistics 2021, pg 54:
World CO2 emissions per year:
1973: 15 Gt of CO2
2019: 34 Gt of CO2
It's almost like the entire universe requires compromise and there are no perfect solutions.
The answer is that we need to produce almost 10B tonnes of CO2 every year. That's something on the order of 1500 great pyramids of Giza (which weighs 6M tonnes) worth of carbon every year.
Isn't carbon capture harder than emitting carbon (hand-waving at thermodynamics here)?
Also, don't all methods of carbon capture produce new emissions again because they need energy, resources etc?
I don't claim to be able to do the hard science here, but the comparison you make seems a lot more far-fetched to me than that of the original comment.
edit: sister comments already make the argument much more clear and I guess the self-doubt of people with responsible intention versus the chuzpe of climate denialists contributes even more to our dire outlook.
If you were being sarcastic: oh well, not helpful.
Quoting a sibling comment here:
> The sad reality with carbon capture is that it's an excuse to put more carbon into the atmosphere than is actually being captured. The oil and gas companies pump billions into capturing carbon are not interested in efficiencies. They are merely interested in making many billions more on dumping more carbon in the atmosphere. If that ever gets close to what they produce, their cost will be so high that they will be out of business
Isn't carbon capture harder than emitting carbon
To burn coal, we have to dig it up from the ground. Is it possible that we one day find a way to "dig it up from the air" instead which is "less hard" than to dig it up from the ground?
Or that we find some other process which has seperating carbon and oxygen as a byproduct? Like some form of photosynthesis? Trees already do this.
The fastest bird can fly 200 mph.
Apollo 10 flew at 25k mph. A factor of over 100.
Maybe we can increase trees by a factor of 100 too.
Most carbon we produce is caused by burning of energy-dense fuel, leaving well:
heat, smoke, gas dissipation and some forms of energy that are useful to us.
If I understood basic thermodynamics at school, this process is irreversible and claims to the contrary are charlatanery.
Firstly, we only need to seperate carbon and oxygen.
Secondly, we get thousands of times more energy from the sun than we need.
So even if seperating carbon and oxygen requires energy, that is not fundamentally a problem.
Clear to see how cynical it is if you keep pumping carbon out of the ground at the same time as trying to reclaim some bit of it from the atmosphere.
> Firstly, we only need to seperate carbon and oxygen.
Separating carbon and oxygen is literally reversing the process of creating energy from fuel. That's how physics works.
Please stop trying to make arguments when you don't even understand the fundamentals of the subject.
I don't agree: using a bird and an Apollo space mission in speed comparison is a completely invalid support for that proposition: the rocket which launched Apollo 10 had to burn 770 tons of kerosene and 1300 tons of liquid oxygen in 150 seconds to achieve these speeds which are possible to be kept then only once outside of atmosphere and outside of the earth "gravity well". It didn't depend on anything of unknown physics or chemistry: Tsiolkovsky published his rocket equation in 1903.
Contrary to that, your "maybe 100 times" would depend on something different from what we know the physics and chemistry say for the last hundred years.
Blind, naive techno-utopianism will doom us all.
That makes zero sense — thermodynamics prefer lower energy states. Coal burns on its own, so that’s the direction of the reaction. It doesn’t become coal on its own, so you have to put energy into that and you net lose on that.
I'm not saying we shouldn't invest money and time in carbon DAC, it will become important later after we stopped emitting tons and tons of CO2 every day.
How do trees get the energy to sequester carbon?
From the sun.
So you use solar and other renewables to power carbon sequestration.
Startups like Terraform are taking things further by converting that into fuels we already know how to use, which will displace fossil fuels: https://caseyhandmer.wordpress.com/2023/01/09/terraform-indu...
They seem to very deliberately not use the name methane in their presentation. CH4 is methane.
Surely there is a simm type game that can illustrate this super clearly?
Civilization: X - The end
game as well
It should include consumerism, garbage and car culture and insane urban planning as well. It could have a satisfying, Idle-game-like pair of bars:
- external costs
- profit
Maybe this could even be presented in a form aking to regular bookkeeping standards.
37.12 billion metric tons of CO2 currently released per year
https://www.statista.com/statistics/276629/global-co2-emissi....
But without those details your comment is just a poor quality and lazy attempt to disqualify people who are actually trying something.
Sadly, I think the situation won’t change until things get a lot worse than they are now. We’re too divided.
The reality is just the opposite: the only option for stopping climate change is to reduce CO2 emissions completely. Now, if we were at a point where we're emitting some few tens of millions of tonnes instead of the 40B we emit today, maybe then carbon capture to help offset the last few trickles would make some sense - but not before then, not in any way shape or form.
> [Galactic Federation President blows his brains out]
And again, carbon capture is simply not a viable technology. It's almost like using a shovel to take water from a leaking pipe and move it to a nearby puddle: lots of effort for little gain, and there's no guarantee that the puddle won't connect back to the leak.
Not to mention, most of those who peddle it are outright dishonest. Most have 0 plans for storage, and instead plan to "re-use the captured carbon", for example to grow plants mute efficiently in green houses, which is to say, to release it back at a slightly lower rate.
And finally, even if by some magic the effort was somewhat successful, and we built up huge deposits of sequestered carbon, the most likely next step is for some idiot politician to start advocating for burning it as soon as the trend became slightly positive.
I assumes that was the entire point of carbon capture?
i.e. instead of introducing more carbon into the atmosphere from oil/etc. you just reuse what’s already in it?
In some cases e.g. airplane there simply seem to be no other options (unless there is a massive breakthrough in battery tech and possibly out understanding of physics). So ‘clean’ burning synthetic fuels don’t seem like a terrible idea.
Of course it all comes down to energy efficiency, but if solar/wind continue growing and carbon capture somehow becomes cost-efficient (assuming free solar/wind energy) it seems like a much better option than continuing oil extraction or even biofuels (which of course is also technically “carbon capture” just not very land/water efficient).
> we are not even a bit ahead.
Of course. But how does it make it different from every other option? Moving to 100% renewables won’t reverse climate change either .
It is impossible for human civilization as we know it to thrive longer term if we keep the current amount of CO2 (and thus carbon) in any way that is circulating.
Of course, capture can and should be the goal after we do the much much easier thing, which is not releasing even 1kg more of the already trapped carbon from the ground.
I’m not sure that true. Han civilizations “thrived” under much worse conditions than we can reasonably expect (by that I mean that technological/economical/social progress historically outweighed environmental factors and I don’t why this won’t be the case in the future)
Also, the Earth has never been as inhospitable to human life as it's expected to be since any known civilization started, so there's no historical precedent to compare to in terms of speed or effects of adaptation.
Sorry. I’m not sure how did I manage to write that, it was supposed to be “civilizations have [thrived]”.
> Earth has never been as inhospitable to human life as it's expected to be since any known civilization started,
That debatable and very hard to quantify. Also it really depends on the region, e.g. Europe was probably quite worse than now during the “little ice age” or the 600s (coincidentally the Arabian peninsula seems to have thrived during that period due to higher humidity).
Climate change was the reason many ancient civilizations collapsed, it seems to have been a pretty regular occurrence and we were only be to break out of that circle in the late middle ages/1500s.
The maximum theoretical efficiency for a combustion engine is about 50%. We'll probably struggle to hit 40%, and that too only after a fair bit of further investment (in particular, materials science investments, and the production of most engineered materials itself requires a fair bit of energy, which generally increases based on the non-standardness/"information-content" of the material (very roughly: "how likely is it that we find a naturally occurring deposit of it on Earth").
So, you cannot really "re-use what's already in it [the atmosphere]". Not sustainably, not while also accommodating growth.
Why would you say that? lol.
If we have a large surplus of cheap solar/wind energy during certain periods (which is unavoidable if they share will continue increasing significantly in the future). Of course yeah, that only works if this process becomes relatively cheap and efficient.
I'm not entirely sure if you do have a misunderstanding, which is why I asked the question. I'm trying to figure out why you think "carbon capturing" is equivalent to "being able to re-mine hydrocarbons"?
Assuming for the moment that the rest of the process is perfect (that is: ignoring that it costs energy to perform carbon capture, ignoring that it costs energy to convert from captured carbon back into some sort of usable hydrocarbon, etc.):
it is already very challenging to get to even 50% efficiency in the engines involved in converting a fuel into electricity; whether that engine is an ICE, or a steam engine often used to convert certain renewable sources of energy into other forms.
Most of that lost efficiency is due to fundamental constraints of thermodynamics : https://en.wikipedia.org/wiki/Carnot_heat_engine
(Essentially, useful engines that produce mechanical work from difference in average energy between two bodies operate in cycles. Suppose we start at time 0, and it takes k time ticks for a cycle to start from its initial state X(0), go through its processes, and return back to the initial state: X(k). The fact is that X(0) and X(k) must be different, they cannot be exactly the same, because then that would mean that it is impossible to distinguish between X(0) and X(k), and your engine is not just an engine, but a time machine. (This is why entropy is closely related to the fact that time is an "arrow": always moving in a particular direction.))
All this to say: it is not possible to use a finite source of energy for a "long time", unless the finite source dwarfs by "many orders of magnitudes" (how large the magnitude, determines how much time before it runs out) the energy drained from it per time tick.
So even if we got carbon capture working as a way to "recycle fuel" (totally, totally ignoring the fact that it will cost more energy to do the carbon capture and store said captured carbon, than the mechanical work we get out of it (the nuclear fusion problem, except not even technically solvable)) it would not last us for more than a few seconds.
(Existing hydrocarbon reservoirs do dwarf our current energy use per time tick, but not by that much, and not if we also want to accommodate material growth, because of the energy cost of also "safely managing" the byproducts of the hydrocarbon->mechanical work process.
The sun in particular, massively, massively dwarfs our current use per time tick. This is what makes "renewables" renewable: they have a massive bank of energy banking them. We have an awe-inspiring fusion reactor just throwing energy at us for a while. How do we convert it into usable work?)
https://e360.yale.edu/features/three-myths-about-renewable-e...
Putting all that together as the context then, my question to you would be: how can one still use captured carbon as a sort of battery in any meaningful way? Is there a misunderstanding of thermodynamics involved on your part, or could you help me understand where my misunderstanding around thermodynamics lies (I am not an expert, just a novice)?
> totally, totally ignoring the fact that it will cost more energy to do the carbon capture and store said captured carbon, than the mechanical work we get out of it
Which is fine if you essentially have free energy during those periods.
Don’t get me wrong, it would only make any sense if carbon capture processes improve significantly but I don’t see how the laws of thermodynamics are an issue if you have an excess of energy you can’t use for anything else (of course other forms of storage might still much cheaper, you can make more aluminum during those times do even less sensible things that carbon capture like mining bitcoin etc.)
for CO2 to be captured, you need some equivalent of the energy from sunlight in photosynthesis. so build these carbon capture facilities in places with powerful natural energy sources, and build them to last eternity
In what way does it solve anything? At that point we built a huge Rube Goldberg machine that burns coal for X energy, spends 2X energy on getting back the carbon (it’s simple entropy), producing that offset from nuclear and renewables.. it may be fun as an art installation somewhere, but to play with this bullshit at the scale of our planet is just ridiculous.
Also, in and of itself life is 100% carbon neutral, or actually carbon decreasing as it is not 100% efficient - that small inefficiency is basically how we got many of our current oil/coal reserves. Biology did fix a big “mistake” of it, and since a few million years ago even trees can be properly “burnt” by fungi, so only some carbon is actually lost due to some extreme conditions (like it fall into whatever that embalmed it for a long time).
The problem is that we reintroduce all these lost efficiency buffers in a few years that is such a fast paced change that it has dire consequences.
Also, the reason for carbon in case of life is energy and a fundamental temporary constituent of the very thing. We do use carbon for many things, but the energy part can be entirely replaced by more efficient generation into electricity which is much more readily applicable than ATP is.
A stated opinion maybe useful as an axiom for you, but most don’t believe this.
Some people believe life has a reason/meaning and is therefore worth protecting through a many faceted approach (one of which is being discussed here).
20,000-25,000 years ago CO2 levels were down to 180-190 ppm.
If CO2 levels had dropped to 150 ppm it would've been a catastrophe. Most plants need at least 150 ppm CO2 concentration for photosynthesis. Life could've just wiped out most of life by accident relatively recently.
The chance of that happening now is impossible because of us, but it goes to show that life is not as in balance with the world as we like to think.
As I wrote, life is not an intelligent design, it has no way of knowing better and thinking of the future: that leftover banana will rot as fast as it can and afterwords leave everything dead in its wake. It just so happened that some form of equilibrium is always met and that Earth has many kind of buffers to change. But it can’t outcompete us in burning coal, we are the new microorganism that almost killed everything by inventing photosynthesis.
We have yet to find another world that has the right combination of googly eyes and string and tape to sustain relatively stable complex life. We struggle to understand the far reaching effects that even simple changes have on our planets systems and ecosystems. We have evidence of the system throwing itself so far out of whack that huge portions of life have died off.
There's approximately three trillion trees on the planet, plus as many more shrubs, bushes blades of grass. The amount of surface area of all their leaves combined is not capturing enough CO2 to help. So to solve carbon capture we would need machines which touch more air than all the leaves on Earth, pumping through a nontrivial amount of the planet's atmosphere, and finding the dispersed 400 CO2 needles in every million haystack molecules of atmosphere.
On the other hand the UK (which raises sheep) imports lamb from New Zealand some 11,000 miles away, by boat or plane.
It's unthinkable that we can solve carbon capture at all, but compared to the ease of stoping the emissions of those flights/ships is fantasy.
You're advocating for degrowth policies.
Degrowth is an evil, destructive, murderous mentality, and if you support it, you're evil.
The only thing we should be doing is building more energy production capacity. Primarily nuclear, and also some solar (to use for e.g. air conditioning and maybe some energy intensive industries that don't need constant power).
Carbon capture is a good way of supporting more energy production.
The litmus test for carbon capture is to see what kind of carbon tax would be needed to offset the costs and hit net zero. If you actually implemented it you wouldn’t see massive scale carbon capture programs and current emissions you would instead see a vast reduction in emissions.
God forbid we forego "business as usual" while the bodies start piling up from continued growth's side-effects that are not impacted at all by kludges and unfeasible patches like "sucking carbon dioxide", "electric cars", and other such not-even-half measures...
I'm a bit confused as to why you think nuclear power would result in a lower standard of living though.
Nuclear wasn’t the biggest issue with the suggestion rather than the carbon capture first approach. However the reason Nuclear is more expensive at scale than battery backed renewables is it takes a great deal of effort that could be used on other things. You can add whatever subsides you want, someone needs to actually do the work.
Obviously wind/solar power plants and batteries etc still need manpower and materials it’s just vastly less. We could run the world on nuclear power, but millions of extra people directly or indirectly supporting the nuclear industry are millions of people not building amusement parks, maintaining bridges, providing healthcare, etc etc.
PS: Risks also get factored into the above calculation at scale. Three mile island didn’t cause significant issues for public health but it did destroy valuable equipment and cleanup was expensive. As such even the cost of insurance represents an economic cost in the long term. 1 or even 500 reactors may have zero significant issues, build 10,000 of them around the world and someone will once again fuck something up.
How much storage you putting there? Because unless it's an hour then nuclear will be cheaper.
The 90% of the cost of 100% solar and wind comes from needing to store up to several weeks worth of electricity.
Also, the vast majority of the cost of nuclear comes from overregulation. Plants were 6x cheaper 40 years ago even adjusting for inflation. And we know how safe those are (safe enough to kill less people per kwh than solar and wind back in 2010!). People/politicians simply seem to calculate a death due to radiation as worth $2 billion to prevent, while a death from lung cancer isn't even worth $1 million (numbers very approximate).
Next both Nuclear and solar/wind want storage/dispatchable power to follow the daily, weekly, and yearly demand curve. Hydro can provide significant flexibility but scaling Nuclear means falling capacity factors and thus higher cost per kWh without storage.
As to battery backed solar, there’s several existing power plants that operate with the ability to store 40-50% of their daily generation capacity that are viable with current grid prices. Significant renewable storage is therefore already cost effective as long as the source electricity is cheap enough.
Finally regulations don’t really explain the price differences alone when you compare different countries and they all have similar issues you need to look deeper. One example of a root issues is modern skilled workers simply demand higher salaries. Most industries have offset this with higher levels of productivity and or outsourcing, but the Nuclear industry has completely failed here.
In theory many of these issues could be addressed, but current plans fail to do so in fundamental ways. Small modular reactors for example have gotten a lot of press but only address a small portion of overall costs. Not useless but you still need expensive workers, thick concrete walls for safety, fuel enrichment, heat exchangers, turbines, cooling towers and ponds, security guards, decommissioning, etc etc.
CANDU reactors attempted to address the need for enrichment but failed to be cost effective for other reasons. And so it goes through many promising concepts that never materialized.
Our society is overwhelmed with low-quality, throw-away products that don't do anything to improve health or well being.
If we want to live sustainably on this planet we need stop producing goods to keep the engines of consumerism running and start cutting back these lunatic outgrowth that are only possible by allowing companies to externalize the long-term costs their products cause. That includes disposal and recycling.
Note that while properly taxing those externalities is the theoretically perfect solution, in practice calculating the costs is so infeasible it would paralize our economy, particularly if we don't allow grandfathering in previous goods, practices, foods, etc.
Merely assessing a particular food type for long term health costs is a 20 year £500 million study.
When assessing a carbon tax for example you can try and come up with an exact figure or you can simple tax the amount of carbon extracted from the ground. That does account for methane leaks from natural gas pipelines, but it’s much better than nothing.
My suggestion is 5$/ton and increase it by 10% per year above inflation, but you don’t need to use round numbers.
Gasoline including manufacturing and transport would be ~2c/gallon right now and ~25c/gallon when cars manufactured todays cars get taken off the road. Which isn’t enough to crush ICE cars today but would rapidly scale demand as additional manufacturing comes online. Similarly aviation wouldn’t instantly be killed off but alternatives would see a significant boost where possible.
Starting higher isn’t a bad idea, but politically I think starting slow and scaling exponentially is reasonably viable.
- bigger increase in R&D and
- bigger reduction in long term projects that emit carbon
Decisions are made on a decades long timeframe. An immediate high tax would penalize old decisions, a gradual tax does more to shape new decisions
Environmental "degrowth" measures (that in reality are just growth measures that take externalities into account) are evil, while the companies and the economic system literally destroying the natural environment and the prerequisites for human civilization on the planet are fine.
You can be pro-sustainability and pro-growth. Examples are (product-neutral) carbon tax and solar&nuclear power.
You can also be anti-growth and disguised as pro-sustainability. Examples are being anti-consumerism, anti-energy-abundance (including being pro-solar without solving for intermittency), and meat tax (i.e. singling out a single product that you don't like).
"More efficient devices" also falls in the second category, as (1) it's pursuing energy-scarcity, not energy-abundance, and (2) it's usually implemented as "uses less energy by being worse" (e.g. dishwasher that runs longer, cars with lesser range) not "uses less energy by being more efficient" (prime example are actually petrol cars, which have massively increased in efficiency in last few decades).
In practice, carbon taxes are easy to game and are counter-productive. The companies prioritize profits (growth) to the exclusion of sustainability; the governments are bureaucratic and slow, so they're always years behind the businesses playing the game.
> "uses less energy by being more efficient" (prime example are actually petrol cars, which have massively increased in efficiency in last few decades).
Jevon's Paradox is that as resource usage becomes more efficient (cheaper), there is a _greater_ overall use of the resource. This isn't bad per se, but it does mean that greater efficiency will not lead to reduced usage.
Nuclear power is one of our best current options, even though it's often derided for cost. But in lots of ways, we can't stop developing nations from burning fossil fuels, so energy developed nations produce from other sources can be use to capture those emissions.
Like most political terms it has been used in a variety of ways by different people.
Some of the classic "degrowth" proponent ideas would reduce the viable Earth human population to around a billion and this would be seen as a good thing. I know three such people personally.
"Survival of the fittest."
I advise you sit down and do the modelling, the data on electricity storage costs (consider kw, kwh, cycles reaction times and annual maintenance please) and wind and solar production variation is available.
IIRC worst case projections of HALYs lost due to climate change is under 10BY
One of them in particular helped write this: https://e360.yale.edu/features/three-myths-about-renewable-e...
Do have a look, if you care to.
Also, I have no clue what "HALY" stands for, and searching for this term didn't lead to anything concrete either. I'm assuming BY stands for 10 billion years.
Those models are wrong, it's as simple as that.
They are probably wrong in ways that would be completely transparent to anyone actually looking into how they are constructed.
I can't say specifically what is wrong about the model you are referring to, but let me give an example that illustrates one common issue: Agriculture, forestry and fishing accounted for ~5% of the world economy last year. Loosing 5% of the economy is not good, but it is not that bad. But in reality, of course, loosing that particular 5% would lead to the total collapse of all civilisation.
Those kinds of dynamical effects are extremely difficult to model, and literary anyone doing that kind of modelling is a crackpot, no more or less. (But crackpots sometimes win prices, so that's good for them I guess...)
My point is: be extremely sceptical of "models" that tries to "value" ecological damage based on current prices. The present biological web on earth is the only place we know in the universe where we know humans can live and thrive. Let's not ruin it for a few percentage points of imaginary economic growth.
If we assume a carbon capture cost of $600 per ton and storage costs of $400 per ton, then the total cost of getting rid of one ton is $1000 just to keep the math simple.
1 kWh of coal power emits 1kg of CO2. This means that your power bill wouldn't double or triple, it would quadruple even in countries like Germany where electricity prices are already high. Even if you believe in capture, you will have to quit coal and go with gas simply because that one only triples the price of electricity. You will also have to get the energy from somewhere. In fact, most of the cost of the carbon capture and storage will be in generating renewable energy to run the capture process to begin with. So what these people are implying isn't that we are going with renewables, no, the power generation of fossil fuels will be a tiny fraction of the total power generation.
Perhaps. But knowing what we know about this issue and:
- our elected officials
- Big Inc and Big Inc leadership
- The momentum from Cronie Capitalism
- The general public's inability to change habits
- Humans fondness for the status quo
- Etc etc etc
How realistic is reduction that extreme? And if we could wouldn't we be leaning in that direction already?
Note: I do agree with you in theory. I wish it were likely. But realistically I know it's not. Things are going to get worse - perhaps much worse - before they get better.
Either we hit the iceberg, or we find a way to blow it out of the water. Avoiding it? That'll take a miracle.
This is false on two counts:
1. The already released CO2 is going to happily keep warming the world for the next century even if we stop now.
2.geoengineering via sunshades or particulates would reduce warming.
1. 'Warming' is better then 'incinerating'. Stopping now is better than stopping later.
2. What else would it do? I can't help but feel "pump even more shit into the atmosphere" isn't a wise solution for all the shit in our atmosphere.
For 2, those aren't real options, given the externalities.
Also, the viability of geoengineering is very much up for debate.
If we could agree that carbon capture is a small part of the solution, direct air capture an even smaller part, and the primary goal needs to be phasing down fossil fuel production, that would be fine. But there is no such agreement, and many major players in both the CCS and DAC space explicitly advertise their tech as a replacement for fossil fuel phasedown, not as an addition.
Energy curtailment (overproduction) will likely be a common reality in some seasons by 2030 and definitely in the following decade.
Building plants that are the most efficient at using that otherwise wasted energy to 'fix' our past mistakes (plus desalination and other uses) are better than just wasting the energy completely.
Geoengineering seems quite possible on paper.
Reflect 10% of sunlight and you'll be experiencing an ice age.
is 40B including the offset from photosynthesis?
Photosynthesis is cool but there are a lot of fires these days and also decomposition.
On the other hand, if you pay Climeworks then they will actually remove the CO2 from the air that you think they're removing, and bury it in deep basalt where it will turn into limestone. It will be quite expensive, and it's a woefully inadequate approach on its own, but it's real and measurable. For most corporations, it's worthless for greenwashing because it costs too much.
(An oil company using captured CO2 to pump more oil out of the ground probably still counts as greenwashing, though.)
CO2 + Basalt !== Limestone
Limestone is the fossilized remains of sea creatures.
Wikipedia says:
"Calcium released by basalts binds CO2 from the atmosphere forming CaCO3 acting thus as a CO2 trap."
https://en.wikipedia.org/wiki/Basalt#Geochemistry
CaCO3 is indeed the principal component of limestone, but not all Calcium Carbonate is limestone. I have no idea whether the process of basalt binding CO2 is efficient; WP doesn't detail the process. Nor does TFA; and I'm not surprised, because Oxy's goals are completely orthogonal to the production of CaCO3.
I also consider woefully small and unscalable, even if real, contributions to represent greenwashing. For example, the plastic straws craze, that attacked a problem that barely even constitutes a fraction of a fraction of a percent of plastic pollution, was pure greenwashing. And by this definition, literally all carbon capture initiatives, even the most well intentioned, are just greenwashing.
It's expensive but it's scalable. There is a vast supply of suitable basalt formations. In terms of land area, it absorbs a thousand times as much CO2 as planting trees.
I have seen a lot of complaints about the sheer number of devices that would be required, but this is the sort of scale that civilization is accustomed to. We built enough hardware to put that CO2 in the air. We can build enough to take it out. The real question is whether it can be made cheap enough in mass production to make a difference. That will partly depend on clean energy costs, but they are dropping constantly.
It's certain that reducing emissions will be more cost-effective in most cases, but for some applications, like long-distance jet travel, we probably can't get away from hydrocarbon fuels for the foreseeable future.
So I'm not personally convinced it is actually scalable for now. I will admit that they seem more serious than others (in particular, more than the company in this article, which is using CO2 to push more oil out of the ground).
For comparison world uses around 97 000 000 barrels of oil per day, or about 3.5 billion tonnes of oil per year.
Switching to synthetic oil (or any other hydrocarbon - I think methane is the easiest) would make a significant difference (and would make renewables much more viable, by solving the energy storage problem).
It's a completely insane amount of energy and effort, and every fossil fuel we burn makes it harder.
I think it's possible and worthwhile. It isn't really any more cartoonish than the wastefulness of our current material culture.
One hectare of bamboo captures approximately 50 tons of carbon per year. Seems like we need only 2M square kilometers of bamboo to offset all the carbon emission of humanity. It's a bit more than Alaska or less than a half of Sahara. It seems like a lot, but I think it is doable, given ease of bamboo planting.
Of course we need to gene engineer variety of plants to capture the carbon for different locations. I believe in fast-growing pine or maple for that matter.
Also, you're saying 50 tonnes per year, but bamboo doesn't live for a very long time, and after it dies, it will relatively quickly decompose and release everything it captured back. So, in reality, you'd have to plant the whole of the Sahara with bamboo and then harvest it every year (or, to be fair, maybe every couple of years), storing all of the bamboo somewhere where it can't decompose, forever.
So no, bamboo (nor any other plant) is not even close to a solution, not at the current rate of emissions.
And we are reaching that point with carbon capture. It does not matter how hard it seems. It still has to be done. There are no other options left.
In other words, you have to generate energy to remove CO2 from the air.
Problem is, how do you generate that energy - on the civilizational scale required - in a way which produces less CO2 than you're removing from the air?
Right now we're already failing, globally, to replace dirty energy with clean. India IIRC has an aspirational goal to be off coal by 2070...!
How do we manage to produce a purely green civilizational-level energy supply, doing it all a second time over as well, and now or soon, to start producing the energy to remove CO2 from the air on a scale which will matter?
I can't believe the cosmic irony that probably the biggest "success" of the environmental movement and arguably its motivating raison d'etre might be the one thing that would destroy the earth's environment. Imagine an alternate reality where nuclear uptake continued at rates of 50s/60s and where we'd be today.
[1] examples: Hitler‘s halt before Dunkirk and his various other silly mistakes (resulting in them not being able to develop the bomb first), Vasili Arkhipov‘s abort to launch a nuclear torpedo during Cuban Crisis, Stanislav Petrov not reporting what their systems indicated to be a nuclear attack…
This kind of attitude is problematic regardless of the topic though. Because whether it works out or not isn't dependent on you, because what you're describing is just noping out of the situation and ignoring it.
And, for those who genuinely do care, one way or the other. That take the many hours upon hours to write out good whitepapers on the topic, how is that panicking exactly? Sure, there is a lot of horror media, purposefully misleading information, and doomer attitudes thrown around from either side of the argument, and some of those average (statistically speaking) folk can probably be described as panicking. And there's also companies doing and implementing things only for the PR, or to remove heat from themselves, or preemt such things, and what have you. But I still wouldn't go so far as to write the entire topic off because some people are panicky and a lot of companies have financial incentives to earn more regardless of morality.
I do agree that, on the current course, I can't see humanity lasting very long, so to speak... that is, if nothing is done about it. Sure, perhaps nothing will work out. Perhaps everything will fix itself if one ignores the problem. Perhaps the fictional student ends up passing either way. Perhaps it won't. But is that reason enough to simply brush our hands of it? To just let it happen? Sitting back and doing nothing won't make things better either. Doing something has—at least—the potential for change, whether good or bad.
At the top of the list would be strategies that utilize biological processes as the capture component of CCS. Kelp and phytoplankton robotic oceanic aquaculture seem the most obvious. Going GMO to increase yield and reduce needs for micronutrients would probably be helpful. Terrestrial CCS would look like either chemical processes or DACCS. I think the Microsoft approach has legs to it if it can be demonstrated, Omniprocessor-style.
For soil health and to combat desertification, it would be wiser to stop rain forest loss and reintroduce megafauna across the world to improve non-wooden plains / semi-wooded land.
Even a full nuclear exchange at the height of the cold war wouldn't have bumped off human civilization.
I'm not convinced by that logic, although as I've never yet died, maybe I could convince myself that I'm immortal by employing it.
Also, among "pro nuclear" advocates there is this tendency to blame the problem on "stupid people" (environmentalists, politicians, Chernobyl watchers, etc) but once you disregard that and let them build their project suddenly you get budget overruns, delayed schedules and failed projects and surprise cleanup costs from decommissioning.
There isn't a cosmic irony. People are against nuclear power because frankly: it sucks.
How the fk is that unique to nuclear powerplants? Also, did you take into account the same shit for coal plants as well, that are multiple orders more numerous?
Issues with commissioning/decommissioning nuclear plants are unique in the magnitudes of sunk costs, both time and money, as well as the somehow still astonishing to many delays and hidden costs that somehow always catch us off guard and somehow are unique to each site and were somehow completely unpredictable that nonetheless somehow happen in every instance.
Also, frankly, this is such a topic that the capitalist view makes no sense - there is no buyer/seller for green-ness (though it can be introduced into the system through laws like carbon taxes), these are costs that must be coughed up by governments, period.
I still believe that a nuclear baseline and a renewable variable energy production on top is the cleanest, greenest solution that actually further our case. There is simply no competition on the efficiency of nuclear.
Due to the complexity of nuclear plants, any issues encountered during building are likely to drastically effect the costs and time required, whereas coal plants are a more mature technology that we already have a lot of experience with. NB. I'm not claiming that coal plants are a better choice (they're not), but that there's less risks involved with the financing and manufacture of them.
If we're discussing the operation of already built plants, then I can't find any stats, though I'm sure there's been at least some explosions or fires in coal plants. I daresay that a coal plant explosion is a lot easier to deal with and resolve than a nuclear plant explosion considering the problems with toxic materials.
I doubt your understanding of the phrase "can't explode".
> There are 436 nuclear plants active on Earth and there was only two accidents in more than half a century,
There have been more than two core meltdown incidents. Have a look at https://en.wikipedia.org/wiki/Nuclear_meltdown#Core_damage_e...
Those idiots are NEVER disregarded, they've put in place a huge amount of extremely expensive regulation that makes nuclear 10x as expensive as it would be otherwise (compare 1980 nuclear power cost per KW to today), all to prevent the occasional Fukishima which kills one person and makes a couple of square miles uninhabitable (technically theres another 200 you evacuate from for a few weeks and then another 20 for a decade or so but a brief look at Fukishima radiation maps[1] shows nothing that would be over the cancer detection threshold[2]).
So you can put them in places where you have the potential for large amounts of cheap renewable energy that would otherwise be unused. Build solar plants in the middle of the desert, build tidal and wind generation on remote islands. There are plenty of places where green energy projects never got off the ground simply because the cost of transmitting it to places with energy demand was cost prohibitive.
The bigger problem is that simply removing CO2 from the atmosphere is not enough, you have to actually store it somewhere and be confident it will stay locked up for centuries, otherwise the effort is wasted.
The answer is simple: trees, moors and other biological processes. That would also work out on scale, as it has before humans have ever entered the play.
A lot of the carbon that first goes into the trees eventually ends up in the soil, which if left undisturbed (i.e. not used for farming) is stable and does not leech significant amounts of CO2.
Admittedly the downside of this is that such soil is almost absurdly fertile. This is in large why slash-and-burns are so popular where ever there's old forest. Indonesia, Brazil, etc. Like it's not even about the lumber, the farmland is amazing for a decade or so.
Stable, as in the amount of carbon that is captured is offset by the amount that is released?
That sounds like after a short while forests become carbon neutral, unless we cut the trees down and do something to prevent the wood from burning or decomposing.
I think we are in agreement?
There's an immediately obvious difference in biosphere density if you step into a forest that was cut and re-planted a fifty years ago, one that was slash-and-burned a hundred years ago, and primeval forest that's been around since the end of the ice age. There's just a lot more stuff growing in a forest the older it gets. Trees keep growing for a very long time as well, easily doubling or even quadrupling the biomass of a younger tree.
All the fossil-sourced carbon we've put into the air the last 100 years or so was, at one point or another put into the ground, mostly by vegetation.
Re-planting forest isn't probably in its own an adequate solution, but it shouldn't be dismissed entirely. Compared to active carbon sequestration, the energy cost of letting a forest grow is negligibly low.
As I understand it, carbon comes from plant matter indeed, back from the Carboniferous period. Back then no life form had evolved that was able to break down wood lignin, so wood could not decompose. That stopped around 300 million years ago when certain fungi evolved, which is why carbon is no longer produced and thus remains a fossil fuel.
Forests are essentially carbon neutral according to every source I can find. I'll be happy to learn otherwise.
I'm confused, where is this CO2 going? Once the forest reaches its maximum average tree size doesn't it stop carbon capturing and just occupies space?
How are you preventing soil depletion given you're cutting down and storing trees? Fertilizer production is very greenhouse gas intensive.
It's not clear to me if direct carbon capture needs to be distributed.
We’re still burning record amounts of coal for energy.
https://www.forbes.com/sites/rrapier/2023/09/04/global-coal-...
Will these processes need to wait until we can get the proper amount of renewable energy?
The general idea is that you grossly overbuild your renewable energy production (solar and wind mostly) and during the middle of the day when the grid is fully saturated and all of the storage systems are filled up you dump the excess energy into carbon sequestration. This is why people are so angry at NEM 3.0, it's cutting the excess energy production we need as a prerequisite for saving the environment off at the knees.
Or you build solar and wind plants specifically for carbon sequestration. Then you don't have to worry about coordinating with the needs of the grid. You don't even need the plants to be on the grid. That frees you up to put them places where there is plenty of wind or solar but no infrastructure transporting electricity which would otherwise by useless for solar and wind currently.
Compressed CO2 is still a lower energy state than the hydrocarbons, so you can get net energy out.
You couldn't end up with the same hydrocarbon that you started with, of course - that would violate the laws of thermodynamics.
So you need to build the structures to keep 20km³ of liquefied CO2 each year (liquefying also takes energy).
The first is that it could use intermittent renewable energy. Solar PV during the day is already cheaper than coal. Just run CO2 removal when renewables generate surplus.
The second is that coal plants are heat engines. Most of the energy released burning coal is rejected as heat. CO2 removal might in theory be made more efficient than this. So it might not be quite as bad as it appears at first glance.
That being said I still doubt this technology could make a dent in the problem without massively cheap energy. It would require either solar panels that are as cheap as vinyl siding or something like practical high yield fusion.
I haven't seen anyone address how we will pay for carbon capture. By the time we start doing real capture, the CO2 produced should be low so carbon tax will be low.
The theory being that power would be essentially free most of the time because there would be a surplus. But then wouldn't people just use more? It's only "free" until people come up with other uses for inconsistently available large amounts of power, at which point you have to outbid them.
More to the point, that clearly wouldn't be "free electricity"; it would be a huge tax on electricity -- on renewable electricity -- used to subsidize the energy use of carbon capture. That's not free because the market price is zero, it's "free" because someone else is paying for it.
It's also crazy. You have the ability to offer cheap renewable energy and you're going to not? What kind of misanthropic policy is that?
One option would be taxing energy. The carbon tax would be small by that time. That would also keep the price higher.
I had idea for retroactive carbon tax, making people pay for their past consumption. Those of us that are older got lots of benefit from polluting CO2, and makes sense to have us pay to remove it. The feasibility depends on the price, and how to charge lots of people who are retired.
Taxing energy, carbon or otherwise, is highly regressive. It only works if you refund the money. Otherwise people freeze to death or go broke.
Taxing non-carbon energy makes no sense because you're not trying to discourage it. You might as well just use income tax.
> I had idea for retroactive carbon tax, making people pay for their past consumption.
The records to use for this are unavailable. Nobody knows how much gasoline someone bought in 1995. It would also generally be impossible to collect; what if your contribution for 75 years of carbon emissions was meant to be $250,000 and you only have $100,000? Do we take your last dime and leave you to starve? What about people who are already dead? Do their kids have to pay?
Retroactive taxes and taxes on retirees are both going to be intensely unpopular.
Which is why people want to justify it by claiming we're going to have a lot of surplus energy to use for it. But how does that work unless the competing demand for energy is negligible, which seems implausible?
Every part of it seems like some company trying to extract government money for their inefficient solution that costs more than it would to reduce emissions by the same amount.
The results I got where that if we built a very large solar farm (500 000 km^2) operating at the efficiency of current commercial solar farms and used all its output to power DAC CO2 removal, that would be enough to remove about half as much CO2 as we currently emit each year. In effect it would be as if we had cut emissions back to 1970 levels.
Note that since the solar farm would just be used to power DAC, it would not need electrical infrastructure outside the farm itself. We just need a place where we can put in 500 000 km^2 of solar panels and a bunch of DAC facilities.
The atmosphere does a good job of distributing CO2 so the solar/DAC facility doesn't need to be near any heavy CO2 emitters either.
BTW, the output of a 500 000 km^2 solar farm per year is about equal to the total yearly energy use of humanity, which shows just how insane the amount of solar energy available is. Let's call this one Human Energy Unit (HEU).
Build two HEU's worth of solar/DAC and we are effectively carbon neutral.
Of course you wouldn't have to build these as 500 000 km^2 facilities. 500 facilities of 1000 km^2 would do, or any other combination that gives us 1 HEU total of energy that is all used for DAC.
How far could we take this?
The 5 largest subtropical deserts in the world have enough room to hold 30 HEUs worth of solar farms.
If we built all those and turned them all on at once it would take one year to remove enough CO2 to get us down to 320 ppm, which is around the levels we had in 1960. Two years would take us back to levels last seen around 1800. 6 years would get us down to pre-industrial levels.
That was all using technology that we have today. It would be a huge project, but it does not require any new science or new engineering. Just a lot of money, politics, manufacturing, and construction.
A quick Googling to find current worldwide solar panel production suggests that it would take about 90 years of current production for the panels for a 500 000 km^2 solar farm, so to build enough to just cancel out current emissions would need about 180 times the resources that currently go annually into solar panel production.
So we'd probably need to increase mining (and several other things) by about 20x if we wanted to use this approach to get enough DAC to bring emissions to net zero.
I think that's about as far as I can go. I don't know enough about the availability of various resources to figure out if the various things needed are abundant enough and accessible enough that we could increase production by 20x.
I thought, of course, of the always attractive "breakthrough" possibility, but ... in particular, fusion isn't it.* So, deployment of renewables is the obvious solution ... and, solar, in particular, has made massive strides in the past decade+.
What you're talking about is actually much more attractive, though. Sounds like a potentially great implementation / execution. And, all of this - much more rapid deployment for (electric) power generation, or, even better, as you propose, I think - seems like exactly the context in which a new "TVA" (Tennessee Valley Authority) or similar (maybe even "Apollo Project") would be the way to actually get it done with the urgency that seems warranted.
Of course, the US coffers have been so raided, it may take the kinds of "national pain" experienced around a century ago to generate the political "housecleaning" required to, well really, "right the "USS USA". As usual, it's not clear the will is there in the electorate. But, I'd say this much for sure: as old as I am now, the behavior of people older than me has disgusted me in many ways for years, and anyone younger than me should be thoroughly pissed off, I think. I don't want to veer into more of a rant - suffice it to say ... if you look at the benefits a certain generation enjoyed, then consider their voting for policies / tax breaks likely to deny such benefits to future generations (already happening, of course - take a look at college tuitions in the US, for just one example), it's a travesty.
In any case, I think another commenter raised a good point regarding the materials requirement. I'd imagine that would be "paid back" many times over very easily by the scheme overall, but don't know for sure ... I know there have been issues with having enough of the right type of sand to make high (enough) purity silicon wafers for chip manufacture ... but, my knowledge is very limited in these areas in general. If anyone has a real handle on what the materials side of this type of scheme looks like, I'd be interested...
* It was always such an attractive idea ... sounds so perfect ... until you know about neutron generation / flux and realize that something like a "tokamok", in particular, is just not likely to be economical AT ALL (the problem being that without some method to contain neutrons or method for preventing generation, you bombard your materials and end up having to replace / "decontaminate" / etc. far too quickly ... at least, based on my sense of best methods available around 10 years ago ... last time I was involved in any work even marginally related to anything in that field). In any case, even if we have or can determine ways of further reducing neutron generation or ... doing something w/ Higgs or something to deal better w/ the neutron problem, seems like it'd take more like a "miracle" than a breakthrough at this point for it to have any bearing on the climate problem on the timescale relevant.
Edit: realized couple oversights / clarifications (not that it's likely to matter, but, prefer to put in anyway): I have nothing against fission apart from its merits. It's been expensive and track record hasn't been good - plus waste, proliferation, etc. concerns. Practically, it's the cost issue (generally related to the other issues I mentioned, of course). I keep waiting for the advanced / modular / "standard design" reactors we've been promised for years... the track record vis-a-vis AP-1000 (already rather old, but, at least deploying) is not confidence inspiring.
Regarding "certain generation", I've known too many from that generation who sat in taxpayer funded jobs essentially not fulfilling THEIR responsibilities as they RAILED against taxes and the POOR. I have a dim view based on personal experience - too many I knew were spoiled and hypocritical to an unbelievable degree. Of course, that doesn't mean there aren't plenty who were decent etc. So, obviously, I don't mean to blanket condemn any generation ... usual qualifications etc. apply.
By simple thermodynamics we can be 100%, not 99%, 100% sure, that the energetic cost of removing CO2 from the freaking atmosphere is higher than the benefit of putting it there in the first place.
A non-sustainable process that converts fuel to CO2 and then into a solid or liquid that isn't fuel could theoretically have positive efficiency, but it is by no means guaranteed to (especially when the competition is heat pumps), even if it did by a small margin it could still cost significantly more, and it implies that you're eventually going to both run out of fuel and convert it all into an enormous amount of industrial waste.
Maybe I should add that I do agree with your conclusion (that replacing the stoves makes sense). I just disagree with the argument from "basic thermodynamics" which gives you "100% confidence".
We will always, 100% of the times, expend more energy to reverse a irreversible process than we could possible extract from this irreversible process.
This statement is valid regardless of the path chosen.
Which naturally spawns the argument 'let's not reverse it, let's do CH to CO to Cx, all we have to do is find x'.
The problem is this is not valid because we burn a lot of fuel.
Even if we found x, it would not be enough to sustain our rate of carbon emissions. In 2022 the world consumed 5.8*10^12 liters of crude oil.
So it would be necessary to include y. And z. Etc until n.
Inevitably including a regeneration step Cn + H to CH + n.
Now the path looks like:
CH -> CO -> Cx -> Cy -> (...) -> Cn -> CH
Which is a closed loop, meaning net power loss. With 100% confidence.
Maybe the one who oxidizes CH pays the bill to remove the CO2 emitted. Is it even possible to put such measure worldwide? Logistics would suddenly be prohibitively expensive for all but the most valuable products per weight/volume. Globalization is addicted to fossil fuels.
Well, that is literally all we did and build and invest in the last century or so. The very power grid of the world is based on carbon fuels. We can't run our carbon removal machinery on dirty power or we would be emitting more than we could possible remove.
It becomes 100% clear the winning strategy is not removing CO2 from the atmosphere, it is replacing all machines and appliances that burn carbon. Worldwide.
Not all are possible, ofc. But a stove ayy.
One still does not imply the other. The question was about what makes sense. That's economically, socially, politically, regionally, etc. Amount of energy extracted via some processes is not the same as benefit. However, benefit is what matters. I guess this discussion isn't moving forward from here.
We can convert one in the other, at different conversion rates granted, but still.
Energy input cost is a line in every company spreadsheet, it can block or allow companies to succeed. Today this line is kept artificially low because we base our economies on a very exothermic open loop CH to CO. Closing this loop is not an option because basic thermodynamics, which is the very logic behind carbon removal.
We have to stop entering this path as much as possible.
Also: "The Bhadla Solar Park has faced some challenges due to its location and scale. One of the main challenges has been dust accumulation on the solar panels, which reduces their efficiency and output. The park is also located in an arid region that experiences frequent dust storms and sandstorms."
Obviously the goal is to move as much stuff off of GHG emissions, but we've done a lot of damage to the atmosphere. If you look at a CO2 graph in the atmosphere over 40,000 years our GHG emissions are basically a vertical line:
And discovering this factoid didn't lead you to realize how insane the whole idea is?
> Just a lot of money, politics, manufacturing, and construction.
Oh yes. Surely just a matter of that. I understand you're more interested in getting ballpark numbers than actually solving this problem though, so thanks for sharing.
For reference, cities currently cover 3 500 000 km^2 of the earth. Also, solar density is still improving, and other sources of energy exist.
Funny enough, this was done in the SF novel “The Hail Mary Project”, and derided by the scientists in the book for furthering climate problems dramatically by turning a normally heat reflective surface into a heat absorbent surface.
Worth investigating before committing our deserts to power collection.
Besides, they don't have to be buried that deep. People are still finding intact bodies in bogs in England from thousands of years ago. They're just a few feet down.
In the desert things decay pretty slowly, too. See Sylvester, the cowboy mummy in a museum in Seattle that was found in a sand dune in Arizona with a bullet hole in him.
To start reversing the CO2 emission we would need as many trees it takes to take up the current CO2 emissions and then a bit more.
From what I found you can estimate every m³ (a bit less than 1 American fridge) of Wood stores 1 ton of CO2. Say each hectare of Forest with fast growing trees produces ~ 10m³ per year (more when they are cut down but they need to grow over a decade+. So if they take 10 years that is 100m³ wood yield at the end).
Humanity produced by some estimates 37 billion tons of CO2 in 2020. That means you need 3.7 billion hectare of forest.
The USA has a land area of 157.7 million hectare. So you need an area of 23 times the LAND area of the United States of America just for trees just to HALT CO² at today's level.
How well are fast growing trees growing in the Arizona desert btw?
You're right that trees cannot be 100% of the solution. But they can be a big part of it.
> you think 25 years is enough to store CO2 in?
It's starting to rot at 25 years, lying in the rain and mud and beetles. There are logs much much older than that lying around the local woods. There are stumps over a century old. My house is 25 years old, and the wood structure that has been kept dry has no rot at all. None. Zero. Simply by keeping it dry.
Also I live in a house made from wood, stone, straw and dirt. Depending on how you count its about 400 years old. before that it burned to the ground once. And the Wooden parts aren't actually that old they have been replaced as recently as 100 years ago. the inside has been redone in the 80ies tho and a lot of the wood got taken out.
Its silly to argue for wood as a storage medium even on the basis of that.
Limited to rot resistant trees, such as cedars. Even then, not shielded from the rain for 25 years and not seeing much rot would be amazing.
The ancient Egyptian tombs preserved things very well as long as the tomb stayed dry.
This story sounded so cool, I just looked it up. Unfortunately, the bullet hole is apparently fake and the reason he didn't decay is because an embalmer deliberately mummified him immediately after his death by injecting him with an arsenic-based fluid, which killed off all the bacteria and insects invading the body.
Cheaper than building a zillion solar panels.
Looks like about 250 million tons a year. Less than a hundredth of the solar farm and carbon capture machines.
We are currently emitting ~37B tons of CO2 per year. That's ~0.375 C, so assuming we only store the carbon, that's ~10B tons of C per year.
For reference, the Empire State Building is ~365K tons - so you'd need to build ~30 thousand empire state buildings per year with the captured carbon.
Which, yes, you then need 30,000 of so it doesn't make the whole thing that much easier.
12/44th of the mass of CO2 is from carbon, so that is 4 x 10^18 g of carbon to deal with if we wanted to store all the carbon current in atmospheric CO2.
The density of carbon depends on what form it is in--diamond is a lot denser than graphite, which is a lot denser than carbon powder. Let's store it as graphite, which has a density of 2.2 g/cm^3.
We'd need 1.8 x 10^18 cm^3 for that much powdered carbon, or 1.8 x 10^12 m^3, or 1800 km^3.
But remember that we are getting all this carbon we need to deal with using energy from massive solar farms. Put the solar panels a few meters off the ground, and dump the graphite under the solar panels. If the graphite was dumped into a pile 1 m tall it would need 1800 km^2 of area.
That would be just a tiny fraction of the area available under the amount of panels we'd have to be using to capture that much carbon. Spread evenly under all the panels it would be less than a millimeter.
Perhaps I should have said increasing the amount of equilibrium biomass or something to more clearly include rewilding or ecosystem changes. It’s not just plants that are a carbon store, after all.
I don’t think this is likely to represent a full solution, if that is the subtext to your comment.
A single 708 km x 708 km would have these corners (Paris, Berlin, Vienna, Milan):https://goo.gl/maps/DTxdVCcK3aYUEirw8 (Rough approximation!)
30 of these: 21,240 km x 21,240 km
Factoid actually means something that sounds true but isn't, which is exactly the case with the post you're referring to because they didn't account for the extra losses on top of the base thermodynamics.
"a small probably unimportant but interesting fact"
China will likely become carbon neutral before the US, current coal plants notwithstanding.
There are two problems, only one of which is discussed here.
We need to remove the last century's emissions, and yes, that can be, and initially will be an excuse to pollute further. I see that as a transient problem: eventually we will start to structure things against it by internalizing other externalities (e.g. other pollution) and expanding the emissions scope (not just oil). It's reality that we can't decarbonize overnight (we could't replace all the passenger cars by Monday, and how many peoples' pensions depend on oil stocks?), so funding cleanup technology on the backs of oil pollution helps get it going.
The second, bigger problem is that the thermodynamics of these plants that suck the atmosphere through a straw is absurd, a trivial calculation that is obvious upon reflection. The atmosphere is f'ing huge, and you need to attack the problem at scale, which means, like it or not, physical chemistry and biology powered by sunlight.
I think weathering rocks may be the better option. It doesn't require any new technology. It would be similar to mining but with steps to crush the rock and either spread it or dump in ocean. We could use electrified version of existing equipment.
It's a great thing that people started working on wind and solar power a few decades ago!
This paper https://newsroom.ucla.edu/releases/using-seawater-to-reduce-... two years ago said that it would need solar plants worth less than the COVID stimulus bill, and it would produce H2, soft water and limestone, all of which can be sold and can displace fossil sources.
Terraform is starting out making methane (natural gas) but will move on to kerosene
https://terraformindustries.com/
You could also ban flight but this seems more practical
Another way of looking at that is: what percentage of the world regularly consumes products that went from one country to another by plane and I think it's probably reasonably high?
The whole thing is green washing theater. It doesn't even address how the "sucking CO2 from the air" is going to be ecologically viable, just a hand-waivy "Think giant fans. Chemical reactions suck the carbon out of the sky and then store it underground." lol
Please go google climate town talking about clean coal. Carbon capture is a scam.
I think what you're responding strongly to is capturing emissions from point sources where fossil fuels are being burned. I don't think that's a scam either - I'd characterize it as an unfortunate necessity due to path dependency - but it's a very different thing than direct air capture.
> Nobody thinks direct air capture is a scam.
Yes, folks do. points up
Two more examples in this thread:
https://news.ycombinator.com/item?id=37452537
https://news.ycombinator.com/item?id=37452761
As a general rule, "nobody thinks that" or "nobody is saying that" are false -- there are always folks who do, sometimes very vocally. We must stop pretending extremists aren't out there.
But there is an actual and notable difference of opinion between point-source carbon capture and direct air capture among people who work in the space.
I do
Any solution that relies on scarce resources like fertile soil, freshwater or agricultural waste is a scam because it has zero impact at this scale and will never grow beyond that.
In theory, there are feasible solutions that would rely e.g on solar energy and seawater, but I'm yet to see one.
If you people "who works seriously on climate solutions" want to be taken seriously outside of your circle, you first need to call out openly and honestly all the scams in your field.
But since they amount to like 95% of it no one dares to disrupt the flow of money. Basically you're like "people seriously working on mortgage derivative solutions" in 2008.
I didn't say I was one of those people. But the reason the people who do work seriously on climate technology don't consider DAC a scam is not that they are dishonest, it's that it isn't a scam; it's a nascent technology that may not work out, but currently seems promising.
> Any solution that draws electricity from the grid is a scam because it's better to shut it down along with the matching amount of power generation.
The nice thing about connecting things to the grid is that then instead of decarbonizing the energy use of a bunch of heterogenous things, you can focus on decarbonizing the grid, and then everything connected to it benefits at once.
I am replying to this nonsense:
> are going to continue producing CO2 regardless of what electric grids look in OECD nations.
And historical emissions are relevant, since the carbon budget relates to the total amount of co2 in the air above pre-industrial levels. That co2 budget was largely "spent" by the US.
My point is it is rediculous to argue for geoengineering while pointing your finger at the third world, when the country with the largest historical emissions still relies heavily on coal.
The world the west is confronted with is this: Chinese and Indians want to live like Americans. The legitimacy of the government in places like China and Bangladesh rest on being able to deliver 6-8% GDP growth every year. They won’t do anything to jeopardize that, and we can’t control what they do. So carbon capture is going to have to be a pillar of any climate mitigation strategy.
Are you saying all of these people are scammers? Are you saying that they aren’t smart for working on it because the idea itself is a scam?
Saying something is a scam implies it’s completely a scam.
Equating NFTs with attempting to sequester carbon is not an appropriate comparison.
Jokes aside, some organisations exist primarily for the benefit of special interests.
In fact, most organisations serve a special interest, it’s just that in many cases that’s “shareholders” and we’ve all accepted that as a stand-in for “the economy” and call it a good thing.
There are many organisations that exist only to serve some agenda.
Most think tanks, for example. Lobby groups, industry organisations, unions, etc…
Sometimes these interests align with the general public interest but most often they do not. That’s why they need private funding — the public demand doesn’t exist.
Hydrogen power is a classic example. Just look at the companies behind the hydrogen companies and it is all petrochemical giants. They’re simply “greenwashing” their dirty energy.
The people working for these special interest organisations are just like everyone else working for shareholder-owned private profit organisations. They’re not evil, selfish, or deluded. They’re just accepting a salary in exchange for labour.
Think of the employees of Enron or Theranos. They weren’t evil, they were just working for companies that were.
Global carbon dioxide emissions from fossil fuels and industry were 37.12 billion metric tons (GtCO₂) in 2021
So we'd only need about 38,000 of these plants to remove the carbon we release into the atmosphere every year.
Then there's also the over 2 trillion tons of CO2 we've already released that's currently overheating the planet.
They’re displacing liquid oil with an equal volume of compressed CO2 gas, so I’m guessing they are emitting way more carbon than they are capturing.
Their solution doesn't solve the problem, but it's a step on the path towards a solution.
https://news.ycombinator.com/item?id=37155241
The primary assumption is that solar energy is going to be almost free within a decade because we will massively overprovision it to balance yearly variation.
Then you need to find a cheap industrial process which uses electricty to do something which has a positive climate impact.
We used to call this swamps back when we thought wetlands were useless and were busily filling them in to create "productive" land, like farmland, thereby losing 85 percent of our global wetlands since the 1700s.
I would like to see a wetlands version of Temple Grandin's guidelines for the beef industry that got widely adopted because McDonald's de facto enforced it. They give you a list of goals or standards and don't micromanage how to achieve it.
https://www.grandin.com/RecAnimalHandlingGuidelines.html#:~:....
Excellence requires some flexibility. Top-down dictates tend to set a minimum standard but frequently also de facto undermine the ability to hit a higher bar.
https://m.youtube.com/watch?v=mCnr0HwW28w
Not everyone likes his delivery, but he’s right more often than not.
You start with a strawman: "people dislike him because of his delivery instead of his message". This way you immediately dismiss critics of him as "focussing on the tone instead of the content".
But if that didn't convince the reader, you immediately follow up with an argument against people who dislike the content, by saying that flaws in content also don't really matter as long as he's more than 50% right.
That means you cannot plant yourself out of climate change in any reasonable time frame.
After trying to reduce our emissions as much as possible, what kind of "best" choice to we have next?
Rather than looking at this as if we are separate from the ecosystem we live in, and try to sequester carbon, I think the better approach is to develop deeper relationships with local ecosystem.
The problem isn’t carbon. The problem is that the carbon is not moving through the ecosystem. Probably one of the more practical things is to separate the local hydrological cycle from the local carbon cycle — that is, plant more stuff; feed onsite composting to the plants; make greater use of greywater, even blackwater; design dwellings and sites with sun and shade and more passive heating and cooling in mind.
Desertification has to do with ecosystems degenerating. While there are regions that are desertifying because of changes in percipitation patterns, our industrial scale agriculture and feedlots are depleting the soil in a way that is leading to desertification, even without changes in climate patterns. We kill soil with fertilizers and pesticide. We got rid of beavers, and the way they reroute rivers and watershed to spread out water, making the land less resilient. We pipe water to grow things in areas we probably shouldn’t. The Great Dust Bowl was not a result of climate change.
Ocean acidification is a result of the ocean absorbing more atmospheric CO2 as a consequence of burning fossil fuels. It has affects on the health of marine ecosystems. It is not a consequence of climate change.
On the trajectory we're currently on, a significant fraction of all species on earth could go extinct. There will be life, yes, but significantly less diverse life.
If we want to have better genetic diversity, it’s not going to come from reducing carbon emissions. It will be things like planting wildlife refuges in your front yard, at least poly-cropping not mono-cropping, letting landraces develop for local conditions instead of insisting on standardized produces. It’s participating within the ecology and not trying to take the entire yield and maximizing usefulness to humans. Reducing carbon emissions will not, by itself, get us there.
Soil is alive, dirt is dead. Healthy soils helps with water retention, and changes the local microclimates. So does designing canopy layers — agroforestry and perennial food forests.
Industrial scale monocropping is not adaptive, and kills off soil. It is fragile, and contributes little to regulating temperatures in the local microclimates.
There are solutions beyond simply looking at carbon emissions or industrial scale carbon sequestering.
That doesn't mean we shouldn't care about maintaining soil qualiy but your comment "heating irrelevant, just deepen your relationship with the environment" is vague and people basically hear "do nothing about the CO2/warming because it's fine, we just need more hippies loving the soil". That's probably not what you meant but it's how it sounds.
This is exactly what I am seeing with the messaging around “climate change” and “carbon emissions” and “carbon credits”. It allows people to continue with the way of life they are used to and feel good about doing their part.
When I say “get connected with the local ecosystem”, I am not espousing a hippie view.
Part of our modern way of life insulates us from really understanding at an instinctual and bodily level, what it means to be a part of an ecosystem or a community. I mean it literally: many people do not actually know what it is like to eat an apple off a tree, let alone a relationship with that particular tree, and all the birds, bees, worms, fungi, and microbes involved with that apple.
I don’t know how to say this any more literally and directly. Advocating for “doing something about CO2/warming” is so far away from getting your hands dirty, and knowing at a deep level, that this is our home, and we’re not the only ones living here, and that the land can very well provide healthy food, and our actions directly impacts the land around us.
Oh and as for warming — the Soviets were able to adapt warm-weather fruit bearing trees, and we can do the same. There are plenty of heat-hardy edible plants, if we are willing to go beyond the small handful of monocropped “food” we have standardized on. We can try using industrial scale solutions, but we are just kicking the can down the road. It is our way of seeing the world around us that lead us here.
What would you do with the CO2? Even if home CO2 capture was practical, sequestering CO2 gas is really hard.
A lot of the best chemicals for capturing carbon are very corrosive and dangerous to work with.
Your best bet would probably be making charcoal and burying it.
Well charcoal is THE "captured carbon" which you wanted to get.
Shouldn't we use something plant based that is able to grow exponentially?
A.k.a. plants?
It might also be greenwashing if presented as a solution in it self, but as a supplement in the transition it might make sense.
Yeah they might help, but let's ask more why questions and then solve that.
Trees can live for hundreds of years. Guess what happens when there are more live trees.
> Unless we chop it down and store it (and plant a new tree!), the tree doesn't remove much carbon from the atmosphere (long term, on average).
But you in fact can do this. Or chop it down and make furniture or buildings out of it, which themselves can last for hundreds of years.
And even if you don't know some cost effective way to keep the dead trees from decomposing, that process itself takes decades after the tree has already grown and died, which at minimum buys us a decent amount of time to figure something out.
The comment I replied to was cynicism rather than skepticism.
I think the $10T or whatever outlandish figure that proponents of carbon-recapture technology plan to spend would be better spent on a land trust on which native plants would be cultivated. $10T will buy an enormous amount of land upon which billions of trees can grow.
If it were actually $10T in public funds that people are proposing to develop carbon capture technology (it isn't, but it is irrelevant whether or not it is), then I would certainly vote in favor of another $10T to buy land and plant trees.
Money really isn't the relevant constraint here. The constraints to carbon capture are, in my view, the same as any other climate technology: public and private will, land availability, and energy. That's in order of most to least intractable.
The global economy could easily absorb $20T of public funding for the DAC + billions of trees plan from now to 2050, if there were the political will for it. But of course, there isn't.
But if there were, the constraint would then be the trade-off between land use to plant the trees vs. solar arrays for the energy to power the DAC machines. But one really nice thing about DAC is that it may not have much constraint with respect to location, so it may be possible to put it in places with plentiful energy that can't easily be used in other ways. (This is not true of land for billions of trees.)
But the will thing really is the biggest constraint, and it's why I'm an "all of the above" advocate. There are lots of great solutions to this problem that you can wishcraft about executing if you were the unchallenged emperor of the world, but there is no path to an authoritarian global hegemon who uses their power to plant billions of trees. And even if there were, frankly I think global authoritarianism would be a worse outcome for humanity (and the environment) than our current climate change trajectory.
So there's no point daydreaming about some perfect "if we would only do this one thing!" solution and getting all frustrated and cynical about how it isn't going to happen because people are too selfish or stupid or whatever. That's letting perfect be the enemy of good. The solution to this will be a cobbled together coalition of a bunch of different stuff - both policy and technology - that people and governments are willing to do.
And you may retort, as many do, "no, that won't be the solution, there just won't be a solution, we're doomed!". And you may be right about that. And I may even have joined the cynical doomer contingent, if it weren't for all the herculean effort at invention over the last half a century having already put us on a much better trajectory than anyone thought we would be on at this point. We're not so far off from being able to beat this thing, we have almost all the technology we need, and a ton of people interested in attacking the problem from different angles both for selfless, but importantly also now for selfish reasons.
It will be good if wealthy and well-run oil companies begin to see a bigger upside in carbon-negative technologies rather than carbon positive ones. Very annoying from a karma / spite perspective, but good from a solving-the-problem perspective.
I don't disagree at all that billions of trees would be an excellent "technology" for this, but it's just naive to put all your eggs in that one not-gonna-happen basket, and it's childish to throw up your hands in frustration that it isn't going to happen and become cynical about other technologies.
Any coal plant - carbon capture plant combination that captures more than it emits would easily be a perpetuum mobile.
So to run a DAC plant from a grid that has a decent proportion of electricity generation from fossil fuels, you are making it worse overall (producing more carbon to power the plant than it is removing), and conversely, if you are running a DAC plant from 100% clean energy, you'd get better bang for your buck if you used that clean energy to displace fossil fuel use (because every kilowatt hour of fossil fuel energy you can replace with clean energy prevents a larger amount of carbon being emitted than the DAC plant could remove with the same amount of energy).
From a thermodynamic point of view would only make sense to run a DAC plant somewhere that already had a 100% clean grid, and only when it happened to be producing a surplus of clean energy.