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Any time someone actually does the math on sucking carbon out of the atmosphere, it seemingly becomes clear that it is simply not scalable to suck the carbon out of the atmosphere. Have you done the math, and if so, why is everyone who comes to the aforementioned conclusion wrong?

There is an argument that it will become cheaper if more investment flows into the technology. For example, when solar power was originally conceived it wasn't cost-effective, but over the years it has seen tremendous gains in efficiency.

That said, I'm not educated on the topic well enough to say whether this argument applies to carbon sequestration.

Same, I also don't think I'm educated enough... but many people who are educated in this area do conclude that carbon removal is a non-starter, so I feel there is a certain burden of proof to claim that it will work. Solar power is a good example of a technology that did better than I would have thought, but there are many others that have silently fallen by the wayside.

I like the idea of getting to net neutral with carbon capture. I even did some napkin math about a month ago. I tried calculating the energy requirements to break the CO2 bond as to determine the number of solar panels you would need. To get net neutral with CO2 emissions you would need to spend something around $8.5 trillion and obtain around 84,584,490,753.28 of 300 watt, $100 panels! Note I did not calculate the cost of the actual carbon capture machines, just energy requirements. I think my number is perhaps still a bit low but I also think this is reasonably doable with global support.

If you have enough green energy to unburn CO2, why not just... use that energy directly? Digging up carbon, burning it, and polluting it, only to spend the effort to capture it, unburn it, and rebury it would be absurd and inefficient.

That being said, I believe carbon capture proposals don't typically involve unburning the carbon - just capturing it and storing it. So the energy situation isn't as bad as your calculations.

These guys seem to have a viable approach to accelerated weathering, a form of carbon removal: https://projectvesta.org/

that's actually pretty cool

There's not enough limestone deposits for this to work - that aren't actually being currently mined.

You cannot use a an active mine for this technique, you have to let the stone lie and weather.

Read their FAQ [1]. They're using olivine, not limestone, and there's a ton of olivine in the crust.

[1] https://projectvesta.org/frequently-asked-questions/

I skimmed their site and I'm yet to read the whitepaper, but I have one question that wasn't so far answered: what about transportation costs? Is this still net carbon negative when you account for the costs of moving all this rock and spreading it on the beaches?

They discuss that in their detailed proposals. There's a lot of discussion on siting and various transportation options. The math ends up working out.

Ok, thanks! I'll head on to reading the white paper then.

Yes, I really want to see that project grow. There was a HN post recently where they gave a lot of fantastic answers to questions about the project: https://news.ycombinator.com/item?id=20403570

Of course, the more we can scale back greenhouse gas emission the less we'll need to extract, so IMO it only makes sense to come at the problem from both sides.

I have repeatedly heard scientists say that planting 1 trillion trees will singlehandedly set climate change back 10 years. I've done the math on that myself and found that such a plan is about 5000 times more cost-effective than driving Tesla vehicles: https://news.ycombinator.com/item?id=19714034

Anytime anybody says anything about the social cost of carbon being greater than $0.50 per ton, I just tune them out.

On what timescale? I.e. trees take time to grow and accumulate carbon. As I understand it, the climate clock is ticking - there's a threshold beyond which some runaway effects kick in.

Growing is the only time they collect carbon. We could plant enough trees to zero out carbon usage (for now).

> trees take time to grow and accumulate carbon

They also burn down or are harvested quite regularly.

Harvesting can be good because it provides space for more trees to grow and store yet more carbon. As long the timber is used for long-term purposes such as housing, then the carbon in the timber kept stored. It's not 100% efficient because when felled the roots and leaves rot and return carbon back to the atmosphere, but AFAIK it's better than not harvesting.

I agree carbon sucking is the only thing that can put the greenhouse effect into reverse.

But imagine if you could have an electricity powered machine that takes out C02 and turns it into solid dense carbon? That is pretty much the opposite of a coal burning power station. With today's technology it would be much simpler to reduce coal burning than taking C02 out of the air.

BTW China alone is building a new coal-burning power station every two weeks. https://unearthed.greenpeace.org/2019/03/28/china-new-coal-p...

What if said super batteries and efficient sequestration never develop? Why isn't creating lower emission power supplies on your list? I understand that the batteries save green power for when it can't be produced, but if we could find other, better, low or zero emission power sources, wouldn't that be just as good?

I'm just confused why those are the two must have technologies, which don't yet exist, and not others, which also have yet to exist on the scale we need.

because that would require a change in personal behavior while the carbon sucking option means it's some scientist's problem and they have no personal responsibility

Find other low or zero emission power sources is the same as "innovation is required to combat client change" as OP. Technically nuclear would be perfect but practically I fear that ship already sailed nothing else up an coming except maybe fusion has any potential as a real baseload powersource.

Without another breakthrough in battery technology solar and wind will never be more than the token effort they are today.

I'm not laying that out as the better option, just that if we're going to create arbitrary lists of things that was solve climate change, I don't understand what the criteria was to make the cut or not, outside of one's own personal preference.

Does it solve the problem is the cut and solar and wind don't make it right now.

On a per dollar basis, sucking carbon out is the most expensive option. Economics dictates that there is lower hanging fruit & best to prevent / reduce CO2 emissions at concentrated sources than to suck out it from an extremely dispersed atmosphere. You're fighting against basic entropy (entropy always wins).

In economic terms, it's a classic tragedy of the commons scenario. Self-interest and inertia wins.

There's no way you're getting people to downgrade their present for some stranger's future without good incentives.

Yeah, this seems to me like the only real no bloody solution of this problem. It basically boils down to energy - we need to have a lot more from sources that don't produce CO2 - likely massive solar or nuclear deployments.

Once you have that, not just CO2 capture but many other similar problmes are quite easy to solve without having to put pressure on people to change the way of their live.

You can even periodically turn part of the captured CO2 into jet fuel, effectively making all planes battery powered (with Earth's atmosphere being the battery).

yeah, betting on technology to solve immediate existential problems given minimal precedent isn't naive or anything. go ahead and post the projections on increased battery capacity, how we're going to find the rare earth material for constructing them all, and how clean tech will magically materialize that will not spike emissions while we build tons of magical unicorn stuff to save the world.

you're the naive one, not whoever you're calling out here.

>It's not gonna happen

Not with that attitude. To elaborate: it's not black & white. You can definitely have a positive impact reducing emissions.

I don't know about carbon capture, but I do think we should be researching sulfur aerosols and iron fertilization. See Oliver Morton's excellent book The Planet Remade.

I'm betting on sulfur aerosols. The energy requirements are modest, the impact is apparently relatively reversible, the side effects seem less potentially catastrophic than iron fertilization.

I look at the street outside my office and simply can't picture us deploying enough carbon capture machines to offset how much we're pumping into the air. I hope I'm wrong.

Also if we suck the CO2 out of the atmosphere we could turn it into petrochemicals and fuel which would help with making existing things carbon neutral.

That's the most viable path to sustainable aviation (rather than electrifying the fleet).

Why are you arguing "A instead of B" when we can do "A and B"?

What about fusion power? It's the dream energy source: the fuel is seawater, the waste is slightly lighter seawater. It seems the perfect target for a Manhattan project/moonshot sort of effort. Giving several teams with competing designs $100B each to develop and test their reactor, in parallel. The potential benefit of near-free clean energy is so absolutely world-changing that it seems worth it to spend on the order of hundreds of billions of dollars to develop it.

>It seems the perfect target for a Manhattan project/moonshot sort of effort.

It would be funny, if it weren't tragic, how "manhattan project" and "moonshot" are the bywords for absurdly expensive government projects. Both these things were peanuts compared to the staggering amounts that politicians routinely fart away on practically overnight whims, for dubious and very likely corrupt reasons:

Manhattan project: $23 billion

Trump's wall: $22 billion

Moonshot: $288 billion

2008 bailouts: $700 billion

All US fusion research investment ever: ~$30 billion

Iraq war: $2 trillion

> The leading countries need to suck the shit back out, that is the only way forward

Its almost certainly for the leading countries to cut emissions and coerce the noncompliers into compliance.

Here's two questions for you which are not hard to answer but, frankly, I do not expect to read the answers here. Why? Because it would show how utterly wrong the suggestion of carbon sequestration for solving this problem was.

First: how much mass (i.e. kg or tons) of C0_2 is emitted per year?

Second: what is the total mass of concrete produced per year worldwide?

(This is only an exercise to give parent poster an idea of the scale btw)

Re your first question, quick googling suggests some 37 billion tons of CO₂ per year. So sure, that's a lot. But then again, not that lot.

Instead of asking questions, why don't you tell us why we couldn't possibly sequester that much carbon annually? How big is the divide between what we could do and what needs to be done?

(I must say the idea of sequestering carbon seems emotionally appealing to me because it turns the problem into something much more tangible. You're not going to get people to cut their CO₂ emissions enough to matter without pushing for a strong emission taxing (which I'm also a fan of). Lowering your living standards doesn't feel like it's accomplishing much vs. the pain involved. Sequestering CO₂ would turn the problem into a numbers game, "how many tons is our country pulling out of the atmosphere, and where do we throw the money to get that number up?".)

It seems to me like we need to do both: tax carbon (ideally globally, but even if half the developed countries do it, it's huge) AND use that tax money to work on research and deployment of carbon sequestration or carbon to fuel conversion.

That's my current belief too.

In principle, with extreme heroic effort, we could sequester 37 billion tons of CO2 per year, but we should be clear on just how extreme “extreme” is. Remember, every single part of the logistical supply chain would need to be scalable a million-fold the same way that the actual sequestration plant would need to be. There are two big practical engineering problems that have to be solved first, that have not been realistically addressed.

First, we would need to double global electricity generation to a first approximation. The laws of thermodynamics make this non-negotiable. Very few power generation technologies not based on fossil fuels can scale like that. Nuclear power plants, realistically, and thousands of them in very short order.

Second, the chemicals used in industrial sequestration produce hazardous byproducts on a scale similar to the CO2 being sequestered, byproducts like hydrochloric acid. Today, this is easy to handle because we produce truly trivial quantities of the chemicals required for sequestration. Not only is there no industrial capacity to produce the required chemicals, nor an obvious way to scale them, there is also no plan for disposing of the billions of tons of caustic chemicals that would be thrown off as a side-effect of their manufacture. It doesn’t do us any good to remove the CO2 from the atmosphere if we end up turning the planet into a superfund site. Nobody accounts for hazardous byproducts of the proposed technology supply chains, which will be produced on similar scales.

As I’ve noted previously, we can reduce this to a much simpler sub-problem that is easy to reason about: what would be required to produce enough potassium hydroxide to sequester 37 billion tons of CO2 per year? All the required facts and figures are public knowledge and relatively basic science. The amount of electricity required per ton is widely documented, as are the chemical inputs and byproducts. And then, once you’ve realized the extent to which that asymptotically approaches impossible, do the same kinds of calculations on the upstream supply chain for the inputs to that process, which is also public information. It falls apart very, very quickly.

What's the basic energy equation of sucking CO2 out of the atmosphere using state of the art today? In say megawatt hours per gigaton?

> What's the basic energy equation of sucking CO2 out of the atmosphere using state of the art today?

Current state-of-the-art has the following equation[1]:

6CO2 + 6H20 + (photons) → C6H12O6 + 6O2

(sorry, I couldn't help myself, the setup was too good) But seriously, I doubt we can beat plants in terms of carbon sequestration efficiency.

[1] https://sciencing.com/photosynthesis-equation-6962557.html

But maybe we could beat the plants in efficiency per square meter. There's nothing saying we couldn't improve on density of matter that photosynthesizes, by e.g. packing the plant matter more tightly in artificial conditions. Nature tries to produce organisms that survive and reproduce. We now have a different set of constraints: we need something that can pull out carbon as efficiently as possible. If it can't self-reproduce, we can reproduce it in labs or factories. I feel (hope) there's plausible biology and engineering work to be done here.

I think the following would be a great start:

- Stop destroying forests (such as Amazon) which are a huge carbon sink for cows which are a carbon source.

- Build more buildings out of wood (wood buildings are carbon sinks) instead of concrete (carbon source)

- All building lumber should be self-sustaining (i.e. replant trees you used to build)

- Stop over fishing and allow oceans to grow unchecked (all living things sequester carbon while they are alive... the ocean is potentially the biggest carbon sink of all and could have several magnitudes more fish and plankton life sequestering billions of tons of carbon)

- Supplement all of the above with man-made carbon sequestration tech

Plants consume about as much CO2 as they create. Its hardly sequestration.

Given that switching to renewable energy is already becoming cost-competitive with fossil fuels, while CCS is a pure cost, what makes you think a major investment in CCS is more likely than reducing emissions in the first place?

> What we need to do is to suck out more than we put in.

Doesn’t it violate the first law of thermodynamics or something like that?

Your idea is never change what we are doing? Crazy.

This is what humanity does best, we innovate our way out of problems (often ones we created in the first place)

Plant trees

Some links to prove carbon capture is not just some fairy tale.

>A Canadian company, called Carbon Engineering, has published peer-reviewed findings, which show the process (carbon capture) can now be done for less than $100 per ton. This is a major improvement on current estimates of $600 per ton.[1]

>In 2016, Hollub became the first female CEO of a major international oil company. ... Hollub’s leadership has brought about a change in thinking. She realized that the company’s carbon-capture expertise could be used not just to make profits for shareholders but also to do climate good. That’s why Hollub is confident that Oxy can become carbon neutral, and why she was sitting at a table in Edinburgh, Scotland in November 2018 with Carbon Engineering’s Oldham. As of this year, Carbon Engineering has raised about $100 million, including about $15 million of government funds. Carbon also counts oil major Chevron and mining giant BHP as investors[2]

>Crystalline nets harvest water from desert air, turn carbon dioxide into liquid fuel ... a chemist at the University of California, Berkeley, reported that he and his colleagues have created a solar-powered device that could provide water for millions in water-stressed regions. At its heart is a porous crystalline material, known as a metal-organic framework (MOF), that acts like a sponge: It sucks water vapor out of air, even in the desert, and then releases it as liquid water. ... By mixing and matching the metals and linkers, researchers found they could tailor the pores to capture gas molecules, such as water vapor and carbon dioxide (CO2).[3]

>Net Power, a startup that built the world’s first zero-emissions fossil-fuel power plant in Texas. Earlier this year, Net Power fired up a $150-million power plant that burns natural gas but has the ability to capture 100% of its carbon emissions.[4]

[1] http://www.climateaction.org/news/breakthrough-made-in-lower...

[2]https://qz.com/1638096/the-story-behind-the-worlds-first-lar...

[3]https://www.sciencemag.org/news/2019/09/crystalline-nets-har...

[4]https://qz.com/1456378/occidental-petroleum-is-now-an-invest...