It's becoming much cheaper to suck carbon dioxide from the air


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So at $100 per tonne, that’s approximately 1% of global gdp to reach break even. Interesting.


The obvious question is, how does this compare to planting a bunch of fast-growing trees?


Wouldn’t planting trees and then cutting them down and burying them be easier?


Well, you’d have to harvest the trees to sequester the CO2 to free up the land to plant more trees. So you either bury them, which opens up a set of land-usage problems; or you use them in construction, which limits the rate at which you can use them, since they would have to reach a certain level of maturity. Then there’s the arability problem, which the method here does not suffer (although it does suffer from a water-usage problem, which may or may not be comparable to that of trees.)

tl;dr it’s complicated.


Well you’ve not been exposed to CLT construction (cross laminate timber) or often referred to as Mass Wood Construction. This is a type of construction that uses absurd amounts of wood to build structures that could otherwise be easily built with a relatively light frame, all for the sake of sinking wood/carbon. State of the art meets height of absurdity.

In other words lets waste mass quantities of wood that could otherwise be used to provide decent shelter for millions of people.


This plus trees made into biochar? Use biochar for fertilizer or other industrial scale purposes.


I read this article the other day… Really interesting to think about… This technique means you could create carbon-neutral petrol cars for a ‘reasonable’ price (if you used wind/solar to run the CO2 scrubbers). Better yet, you could make carbon neutral fuel for jets and ocean freighters. Hell, it could be a great technique for storing excess solar energy captured during off-peak hours. On top of that, it could provide true oil independence and make hazardous extraction less enticing.

But on the other hand I see this as a potential way for industries to continue to pollute with a little green-wash on the side. And I’d be afraid that it could de-incentivize lowering carbon emissions in the first place. Carbon-neutral petrol could also kill the need for full-electric vehicles (but maybe hybrids are better anyhow?).

Finally, something like this would probably need to be subsidized by government; not sure it would be economically viable unless industry is forced to reduce net carbon. In any case, if the tech proves cheap enough it could be a powerful tool for carbon reduction.


Last time I read about this (which was quite some time ago) there were musings about chucking them down mine shafts. That doesn’t sound particularly practical – but then, the question is whether it would ultimately be cheaper than $94/tonne of CO2.


Right, so, capturing and sequestering CO2 in some inert form that keeps it out of the atmosphere isn’t a bad idea. Turning the CO2 into a fuel that will then release it back into the atmosphere is a terrible idea though.

Simple thermodynamics–capturing the CO2 and turning it into something else requires more energy than releasing the CO2 produced, meanwhile we keep burning things and dumping CO2 into the air, some of which we’re capturing, using a bunch of energy that has to come from somewhere to reverse entropy and turn it back into a fuel which we burn and put back into the air.

At best we might slow things down, but what’s more likely to happen is it will make things worse. These sequestration operations are going to be used as an excuse to roll back climate change regulation, and we’ll end up with a situation that’s roughly analogous to the problem with building more roads to reduce traffic–it works at first, but that just means more people drive and drive in less efficient ways so the roads end up basically exactly as crowded as they were to begin with.

Using sequestration as a means to capture CO2 and put it back into some stable form as a means of hopefully reducing the intensity of climate change is a pretty good idea, but it’s not going to be a profitable one, and frankly are we really going to let the world burn because it was just “so gosh-darn expensive to fix it?” I feel like people 50-100 years from now aren’t going to find that justification very damned satisfying.

That’s not to mention the fact that CO2 isn’t the only gas that’s contributing to climate change, and it’s more complicated than just greenhouse gasses. In addition to the sun, every bit of energy we release from a stored form creates heat, and that heat has to escape the planet somehow. In theory it radiates relatively slowly from the earth (radiation is the slowest form of heat transmission) but greenhouse gasses slow that process which results in global warming. We could have a situation where even if we were able to sequester many tons of CO2 and methane from the atmosphere, the population is growing wildly, which means more energy use, which means more heat which raises ocean temperatures, increasing cloud coverage which itself traps heat.

Either way, sequestering carbon is a good idea, turning it into fuel is a terrible idea, fixing the planet probably won’t be profitable, so we need to remove that right from the equation, and even if we sequester tons and tons of CO2, we’re still far from out of the woods.


Plant shellfish. Calcium Carbonate. Get a nice meal out of it too.


I have, and that’s not really an accurate summation of CLT not the possibilities in using it in structures.

First off, CLT elements are often used in place of steel, which is unquestionably heavier than mass timber.


On the other hand, production of other fuels requires a bunch of energy too.

A better question might be: what is a “synthetic, low-carbon fuel”, anyway?


I’m still a bit skeptical. This is basically a more efficient way to concentrate CO2 from the air. It doesn’t really solve the sequestration part. Using the Sabatier reaction to produce hydrocarbon fuels is certainly useful for cases that can’t easily be electrified (like airplanes), but ultimately we actually want to “permanently” remove a lot of CO2 from the air. There are basically three ways: form a solid that is energetically cheap like CaCO3. The problem is that most available precurors to such reactions are already carbonated. We bake CaCO3 to release CO2 and make quicklime (CaO). Option 2 is to form something energetically costly like hydrocarbons and sequester them. Basically turn energy back into fuel and bury the fuel. This makes the most sense but is obviously expensive and inefficient. Option 3 is to bury the CO2 as a gas by pumping it back into abandoned oil and gas wells at high pressure. This is the cheapest solution, but raises the problem of controlling leaks.


Making a usable fuel without having to extract and refine crude oil makes good sense to me, it that we don’t end up with left overs that they are forced to turn into some other product (read : plastics, which get dumped everywhere, all over the world). Obviously, its not going to be the sole saviour we would all like to see, but it is part of the answer.


What’s wrong with leaving the trees to grow, die, and rot naturally? Do forests not replace fallen trees as a matter of course?

Mulch is a great option and greatly reduces the amount of chemical fertilizer we use to grow our food.


The amount of heat from combustion is insignificant and is not cumulative like GHGs (which contribute to GW as long as they remain in the atmosphere).


the water can’t be too acidic though.


Glad to see that an engineering solution is becoming more affordable. However, ecosystem solutions may be even more affordable and useful, given that the engineering solution is designed to produce a carbon-based fuel which will be burned and re-release CO2 into the atmosphere.

According to this 2013 article (, a hectare of jatropha trees planted in desert environments has an estimated cost of $56-84 per ton of CO2, cheaper even without taking the re-release of CO2 into account and probably cheaper now than in 2013.

I would also suggest the book Geotherapy: Innovative Methods of Soil Fertility Restoration, Carbon Sequestration, and Reversing CO2 Increase (, a peer-reviewed compendium of existing techniques that improve soil quality while increasing carbon drawdown through agriculture and forestry.

Other methods, which include water management and ocean farming versions of geotherapy, can be found in the proceedings of the conferences sponsored by Biodiversity for a Livable Climate at their website,

If anyone is interested, my notes on the book Drawdown are available at


About 15 years ago, I did a few back-of-the-envelope calculations while on a school field trip (yeah, I was that kid) and said to a friend, “You know, it looks like it would take about 3-4% of GDP, sustained each year, to solve global warming. Why don’t we just do it? Would it really be so bad to lower our standard of living to where it was two years ago?”

Today, I do know the answer(s) to why we haven’t done it. But they’re just as unsatisfying as ever.