In theory, rocks from Oman could store hundreds of years of human CO2 emissions | Hacker News Reader

In theory, rocks from Oman could store hundreds of years of human CO2 emissions

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The best long-term carbon sequestration medium we have is wood.

It is the slow and unsexy algorithm of:

Plant trees, and then build things with them. Be careful not to burn them. Repeat

I was under the impression it was phytoplankton, but I can't seem to find a source.

Your theory sounds good until you consider the practical aspects of the last step:

> Be careful not to burn them. Repeat

So what do you do with the wood? A billion years ago, your plan would have worked out brilliantly. Some say it's where our oil came from. But now we have fungus among us that evolved to rapidly turn your wood right back into CO2.

Unless you sterilize the wood and bury it deep in the ground where it will never be exposed to air or spores, you're right back to square one. Also there's the logistics and carbon footprint of burying and sterilizing the wood.

You're not the first person to think of this:

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2266747/

Could we mass pressure treat wood to prevent it from being eaten?

That only works for a period of time depending on conditions. In this case, even a few hundred years wouldn't be good enough.

Hundred? If the wood is touching soil, try a few decades at best. I just replaced an old rotted out deck that was all pressure treated lumber. Also EPA considers it a hazardous waste.

https://www.epa.gov/ingredients-used-pesticide-products/chro...

Sure, if you want to trade one ecological disaster for another.

Just build structures with it, cover with tile or metal to keep the water off, and it will last thousands of years. See Nara, Japan for examples.

From what I've seen in Nara they actually ritualistically rebuild the wooden structures every couple of decades or when there is a fire.

Yeah, IIRC almost none of the old Japanese wooden buildings are original. They all have a strong ship of Theseus theme going on, but philosophically the Japanese tend to view the building as the place and purpose and layout and not the individual boards that are used to build it so it doesn't get communicated.

One can use it to build hempcrete homes. Instead of burying it, one would encase the wood frame structure into a hydraulic lime + hemp hurd mixture (cemented single stud framing). The hemp also sequestrates CO2, the lime keeps everything fungus free and further absorbs CO2 from the air as the walls cure.

http://en.m.wikipedia.org/wiki/Hempcrete

I think about this topic seriously, but reading what you wrote made me realize this rhymes really well:

humungous fungus among us

and I just had to point it out :)

But does it rhyme in both British and American English? Just wondering as English is not my first language.

Keep growing them?

A well built and maintained wooden house should last over 300 years. There are such even in North America.

It requires massive timber though. And to get that on a larger scale, you need good long term forest management policies. Plan for something else than paper or chipboard or glulam.

So, not a technical problem, but a political one.

I think the direction is good, the conclusion not so much. Nobody has the use or space for a couple hundred timber houses per person on the planet to cope with the current emissions.

But if executed correctly (Drones sowing and harvesting millions of tons of fast-growing wood / switchgrass per year) and then correcty getting rid of it so it can't decompose (i.e. probably drying and/or sterilizing it), it might solve carbon capture.

That being said, it all involves lots of space, mineral fertilizer and moving parts — on top it might be disastrous to any animal ecosystem trying to get hold in those woods. I'm not sure we wouldn't be better off with stationary carbon capture stations eventually.

It's only going to be one part of the puzzle, at best. But replacing concrete, steel and aluminum, all causing large CO2 emissions while the raw material is created, should be a benefit.

Anyway, you can also store a lot of the carbon just as forest, though it's more of a "one time" use of the land. Trees can also live for hundreds of years. And the soil can also store carbon. At least over here, large trees can often survive forest fires too.

But it requires changed policy, it's not a technological problem.

True. But there are plenty of times currently where plastic could be replaced with wood. From broomstick handles to sporks, we use a lot of plastic that doesn't have to be plastic.

Cost is a consideration. But plastic over the long term has a cost, that isn't factored into the manufacturing+sales cost.

I'm not suggesting this would solve the problem. That single magic bullet doesn't exist. But it can't hurt either.

Well, problematic are mainly dead trees. Thus, I do not see why quickly growing and dying wood should be best. Instead I see better suitability of trees that can become very old, hence avoiding dead wood which turns to CO2. Also, ever greens avoid generating dead leaves.

Swamps or bogs may be more efficient on a net fixation basis. Anaerobic deposition may better preserve the carbon as well.

I'm not immediately finding a comparison of various ecosystems, though there's this on Indonesian swamps:

https://www.sciencedirect.com/science/article/pii/0045653593...

And:

"Peatlands only cover about 3 percent of the Earth but they accumulate more carbon than tropical rainforests," says biogeochemist Nancy Dise of Manchester Metropolitan University in England. "In terms of sitting there kind of quietly year after year packing away massive amounts of carbon, nothing tops these peatlands."

https://www.scientificamerican.com/article/peat-and-repeat-r...

"Plant trees, and then build things with them. Be careful not to burn them. Repeat"

I don't think this pencils out. We use quite a lot of machinery and trucks and electricity to build with and it's not obvious that the carbon sequestered by the wood in a structure is larger than the amount of carbon expended in all aspects of the building of it.

In fact, I suspect it might be quite a bit off ... a dry 2x4 weighs very little and there is a lot of driving and idling and generating and power usage involved in building.

Clean solar/wind energy with batteries? The OP did say long term.

Also wood buildings can look cool https://www.google.co.uk/search?q=wood+buildings&num=30&tbm=...

and maybe our future AI robots can build them.

Only factoring in the manufacturing cost (that is, not including the cost to haul to site and use) wood products are solidly carbon positive [1]. Lumber harvesting, hauling and processing is surprisingly efficient: It's a cutthroat business with razor thin margins.

The more important aspect is that something else would have been used instead. Each building that is of wood construction is one that wasn't built primarily with steel or concrete.

Also, effects of scale can be significant. As a simple example, there is about 200 billion kg of carbon sequestered in the contiguous US just in wooden telephone poles. If you can find a widescale use that makes economic sense, you make more immediate sinks. If you can also find ways of long-term sequestering the waste as it enters end of life, you can make ongoing gains in the CO2 balance.

[1] - http://articles.extension.org/sites/default/files/CIWP%20pub...

It is actually better to turn the wood into biochar and put it back into the soil.

Indeed!

However, we do not know how long biochar lasts when used as a soil amendment [eg. 1]. Also, it's only useful in this way when loaded and applied to poor soil in the tropics [2].

For long term storage of CO2, it might be better to just bury the main products of pyrolysis (biochar and pyrolysis oil) where hard coal and the oil once used to be - deep in the earth. Burying both products should also make it cheaper (from a carbon mitigation point of view), since it's hard to make useful products from the pyrolysis oil. The biochar also doesn't need to be as clean as when used for soil. One can even pyrolyse old tires (and possibly plastic).

The problem is, of course, that there are no long-term studies about the stability of biochar (and the bio-oil) in deep layers.

[1] https://onlinelibrary.wiley.com/doi/abs/10.1111/gcbb.12266 [2] http://iopscience.iop.org/article/10.1088/1748-9326/aa67bd/m...

The reference you provide says 556 years. It is actually lasts far longer the deeper you put the biochar in the soil since we do know that breakdown requires oxygen and/or UV light. In some soils the average age of the carbon is 5000 years.

The best way to implement this is by slash-and-char of the tropical forests. I have done the calculations and using less than 30% of te tropical forests we can pull out all the CO2 being addded from human activity. It would also create a viable industry in some of the most poor regions in the world.

Would it be feasible to do something similar with ocean water? I’m thinking Northern California or even south - somewhere trees aren’t prevelant already and without using scarce water.

Why not produce electricity, hot water and hot air by gasifying the wood, and then burying the biochar that is left over after the gasification process?

All Power Labs (allpowerlabs.com) produces small scale reactors that can do just that.

The good char systems do this. Some of the really clever systems can be used to fix nitrogen and turn the biochar into fertiliser. the whole thing can be combined with improving local agriculture slash-and-burn regions.

The problem with wood is that it's not in a thermodynamic minimum energy state. React with oxygen, or thermally decompose to lighter hydrocarbons -- and you will get CO2 coming back.

In contrast, the carbonate minerals from the reaction of CO2 with these silicates ARE thermodynamically stable. Even if left exposed on the surface of the Earth they will not release CO2 back into the atmosphere.

Actually partially burning the wood and creating charcoal is a better means of carbon sequestration. Terra preta, also known as biochar, is thought to last about 10,000 years in the soil.

How dangerous is it to breathe in particulate matter from peridotite? There's another approach to making sequestration within these rocks economical - we could use underground explosives to simultaneously disperse peridotite particles into the air and uncover formations that haven't been exposed to CO2 yet. This would drastically increase the surface area and hence absorptive power of the rocks.

Even if this could be done in a manner that keeps the air safe to continue breathing, the other problem from doing too much of this is that it could increase the Earth's albedo and have a global cooling effect (akin to when volcanic eruptions on earth have caused famines, skipped summers/growing seasons). But in some ways, that may make this the perfect worst-case-scenario solution to runaway global warming. We could periodically use "clean" nuclear detonations to put enough particulates in the air to reduce the global temperature and sequester carbon. Once the particulates settle, if there is still too much CO2, we could do another round of detonations, etc.

This is how apocalypse movies start.

Well, I'm sure in a limited case it wouldn't be that dangerous. But yeah, regarding the nuclear detonations, that's why I think it would have to be a last resort. Like, last resort as in a situation where humanity is in danger of extinction or in making Earth mostly uninhabitable.

So, now then.

More like 30 years ago.

But yes, now would be good too.

In that case we should adopt a more cavalier attitude toward nuclear weapons. If we allow at least one nuclear exchange between two nations we could help offset the effects of global warming for a good while longer.

Ocean acidification isn't helped by nuclear weapons.

So yeah, the best way to preserve the environment is to blow up mountains. What could go wrong?

After all, a scientific community that still discovers things at the most fundamental level, like how this or that emission or process that has been going on for billions of years affects the ecosystem, is 100% to be trusted that it knows everything there is about the byproducts and consequences of such a process.

It's not like until e.g. merely 80 years ago scientists still helped produce and sell radioactive consumer products. Or they considered thalidomide safe. And any number of such things...

It seems to me there is much promise in influencing the natural carbon cycle in these kind of ways. Apparently natural processes release and absorb about 800 gigatons of CO2 annually against human emissions of 29 gigatons or so, so there seems a lot of scope to try to tip the natural balance a few percent. Especially if we go carbon neutral and are then looking to reabsorb a bit.

https://www.skepticalscience.com/human-co2-smaller-than-natu...

>processes release and absorb about 800 gigatons of CO2 annually against human emissions of 29 gigatons or so

We don't see to be growing more trees anytime soon, and we aren't adding any new oceans either.

There's this kind of thing "Surge in plant growth explains slower CO2 rise over past decade" https://www.carbonbrief.org/surge-in-plant-growth-explains-s...

which has happened without really any planning. It's just that sort of stuff could be actively encouraged.

I remember reading this article waiting for my haircut this morning.

Here was my biggest takeaway:

> More realistically, he said, Oman could store at least a billion tons of CO2 annually. (Current yearly worldwide emissions are close to 40 billion tons.)

So we're looking at 2.5% sequestration of what we're currently adding, from the largest deposits in the world. Best case, realistically.

The whole thing sounds like a total non-starter.

Sometimes the way you solve a big complex distributed global problem is a bit at a time. It’s unlikely we’re going to find one single global solution to carbon sequestration.

>Sometimes the way you solve a big complex distributed global problem is a bit at a time.

An example of such a time, from various available such historical "sometimes"?

There are so many examples I don't even know where to start. Disease eradication (through education, sanitation improvement, suppressing disease vectors, vaccination, etc), then there's poverty reduction, the way piracy was eradicated in the 19th Century, the way ozone depletion was tackled. There are endless examples.

Anyway, what are you actually saying other than taking a cheap shot?

Isn't it the case that much of our emissions are absorbed already (e.g. by oceans, about a third of human activity) such that the 2.5% is a lot higher on the net amount.

e.g. say we emit 100 and absorb 95, absorbing 2.5% of our total emissions actually cuts net emissions in half. Or are you already figuring that in?

Or, you know, maybe we could just emit less CO2 to start with.

To be clear, I'm all for research about carbon sequestration, but it should not be an excuse to keep polluting irresponsibly. On the long term, we simply can't get away with compensating all our big negative impacts with big positive ones - how about introducing some moderation in our lifestyles instead?

If we want to avert a bad scenario, we need to both drastically reduce CO2 emissions and find a way to sequester the CO2 currently in the air (either through technological means, or through something like making big tracts of land into forests). Just sequestering is unlikely to be enough, unless it is extremely efficient.

"Fake" or rather misleading news!

So:

Geologists for a long time assumed the carbonates found with igneous rocks resulted from CO2 reacting with these igneous rocks were formed very very long ago.

A scientists uses carbon dating and discovers that the carbon in these carbonates was in fact formed relatively recently.

This should prompt 2 questions, but seemingly only prompted the first:

1) If unreacted pyroxenes and olivine in these rocks can capture CO2 to form carbonates relatively fast on geological timescales, can we help this natural process speed up?

Answer: yes, but unclear at what energetic cost, and unclear what to do with these carbonates afterwards.

2) WHERE do the carbonates end up, if the carbonates from older carbon are mysteriously MISSING???

Answer: reacting back to CO2 upon rainfall, or by erosion and weather ended up in seas and lakes!

One does not need rocks to create cabronates: simply expose water with CO2 and CO2 will both absorb as (CO2)_gas and also react with water to form carbonic acid H2CO3:

(H2O)l + (CO2)g <=> (H2CO3)l

If we take the resulting say magnesiumcarbonate from the rock that has captured CO2, and put it in water, it will first dissociate like all salts (metal, non-metal compounds) resulting in free mobile Magnesium ions and free mobile carbonate ions. You might as well just let CO2 in the air react with the sea acidifying it...

They pretend the carbonate form is a sink where we can dump our CO2, while in fact this very interpretation is inconsistent with the original discovery that the carbon in these carbonates is young. If it was truely stable the carbonates would predominantly contain old carbon.

So unless they have a plan to store these carbonates and protect it from rainfall, and prevent it from flowing into bigger bodies of water, I see no solution, only excuses to appear green such that banks can invest "green money" into these mining companies again, or perhaps to get "green subsidies" or perhaps to escape carbon taxes...

Plants are pretty good at capturing carbon, why would anyone want something more expensive and difficult?

The area of plants needed to capture current CO2 emissions would be impossibly large. The energy efficiency of photosynthesis is horrible. In contrast, mineral carbonation is an exothermic process, in principle requiring no energy input.

It's an intriguing idea. But you'd need to move humongous quantities of sone, air and water. Without releasing so much CO2 to negate advantages.

Which is why we need nuclear power.

Perhaps so. With inherently safe designs, though.

Not some simplistic scale-up of Rickover's submarine engine.

>With inherently safe designs, though.

Funny how with reactors always the new designs are "safer" or "100% safe". Until time passes, and those are the "old unsafe designs". It's like there's an industry selling and promoting them each time (no, wait...)

After Fukushima nuclear fission power is dead and burred.

Not in China.

https://www.marketwatch.com/story/china-set-to-overtake-us-a...

Presumably you're suggesting nuclear because it's carbon free. But if that's the goal, both wind and solar are cheaper now. So nuclear would be a misallocation of resource, reducing the ability to spend on other efforts.

And if that carbon-free electricity is going to charge the batteries of machinery to do this, wind and solar will be just as good at that.

“In Theory” is doing a ton of hard work in the title to cover that up. In theory we could run internal combustion engines on sawdust, or fly using helium party balloons, but they’re not good ideas when you look at the full checklist of pros and cons.

Could we do this on Venus to start terraforming?

https://en.wikipedia.org/wiki/Terraforming_of_Venus#Capture_...

Sounds like it could more than halve the atmosphere (from 93 times Earth atmosphere to 43 times).

Though worth remembering that the surface of Venus is an untouched wilderness region containing billions of years of geologically significant information. I'm all for walking around a balmy Venus, but if it involves pulverising the surface, we need to be extracting all the scientific information from the untouched wilderness area as we do it, because a lot will be lost forever otherwise.

Find a way to extract enough energy from this reaction (it has to be at least slightly exothermic) to pay for it, and we're good.

I think Yogi Berra said it best:

In theory there is no difference between theory and practice - in practice there is

https://en.wikipedia.org/wiki/Carbon_capture_and_storage#Min...

Not Yogi Berra, nor any of the other celebrities quotes end up sticking to, but one Benjamin Brewster:

https://quoteinvestigator.com/2018/04/14/theory/

in theory said by Yogi Berra.. but in practice ...

It could store even more years' worth if we decrease our emissions.

I don't mean a general "we." I mean you, reading these words, and me. You can decrease your emissions, plastic pollution, etc. No technology needed. No loss in quality of life.

The problem with that is that most of the CO2 emissions we depend on as individuals are beyond our control. Things like the emissions generated in growing, processing, packaging and transporting the goods we buy, our food and clothing, our mail, the utility resources we consume, the services we depend on, public transport. Yes we can do thing in our daily lives but in reality it’s a tiny fraction of our actual CO2 footprint. That’s why societal and industrial level action, and therefor public policy is so important.

The biggest environmental issue we can affect in our daily lifestyle is recycling and reducing household rubbish. It’s another important issue and one where we really can make a difference in our everyday behaviour.

It isn't beyond our control if we actually baked in the cost of co2 emissions into the cost of the goods and services we use. That said, these things end up being very hard to calculate.

I think it makes more sense to put the cost on the emissions themselves (i.e. their production), not on the end-products. In a perfect world these two approaches would be equivalent, but since there are relatively few emission sources compared to end products, I think it would be easier to enforce.

The problem with mixing carbon taxes with global trade in general is that if some countries don't participate in carbon taxation, then carbon-intensive production will just shift to those countries. Game-theoretically, it's a relatively unstable equilibrium because if all countries are participating, then a country that suddenly refuses carbon taxation could stand to benefit enormously.

Well, there is a solution to that: border tax adjustments.

Carbon taxes — and I mean at the well, not those bureaucratic, corruption-prone cap-and-trade schemes – are the simplest, cheapest, fastest way to get a carbon-free economy off the ground. And if you make them revenue-neutral, you can get conservatives on board as well (look up "fee and dividend").

How would you make it work in practice? Would every country sign a global accord to tax oil wells, coal mines, etc?

Or would you have an import tax on such materials? How exactly would you adjust taxes at the border?

I also think this is the best solution, but I'm not exactly sure how you'd implement it without loopholes.

Yes, import taxes would be the temporary solution. This is my go-to resource: https://citizensclimatelobby.org/carbon-fee-and-dividend/

I recall reading that cargo and fishing vessels (or is that all seafaring vessels? Or all ships and boats?) produce at least as much CO2 and particulates as the cars we drive, as the ships aren't nearly as clean as road vehicles.

I've no source for that, though, it was quite some time ago that I read it.

No, this misleading stat refers to sulfur and soot emissions, not CO2. It's true that ships at sea burn a cheap sulfurous fuel, "bunker fuel", because there's nobody to inhale it out there. But it's misleading because people think this stat refers to CO2, which it doesn't. Ground transport produces far more CO2 than ships, which by weight are the most efficient way of moving anything.

But CO2 isn't the only green house gas. There are gasses with >>1 CO2eq

That's true, but the sulfur emissions from ships do not have this effect. They actually have a slight negative greenhouse effect, because they reflect light in the upper atmosphere.

According to the EPA, 27% of total greenhouse gas emissions come from transportation, with only 2% of transportation emissions coming from boats. https://www.epa.gov/greenvehicles/fast-facts-transportation-...

However, I also recall reading that boats produce a ton of emissions (I'm pretty sure it was a popular reddit post about how the huge oil tankers and shipping containers account for almost all ship-related emissions). One explanation: the maritime emissions may be underestimated due to the practice of ships using flags of convince. This website, and wikipedia and a few other sources, claim that the global contribution of maritime transportation to GHG/CO2 emissions is around 2% http://www.airclim.org/acidnews/new-figures-global-ship-emis...

2% of the total is still nothing to sneeze at, though. Since tankers and container ships are so big, it's likely that individual ships are some of the largest individual contributors to emissions. Maybe we should allow/subsidize these ships to use nuclear energy

If you trace that number used in the quick facts website to the report its data is based "Inventory of U.S. Greenhouse Gas Emissions and Sinks 1990–2015" you get the following explanation for the data Note that these totals include CO2, CH4 and N2O emissions from some sources in the U.S. Territories (ships and boats, recreational boats, non-transportation mobile sources) and CH4 and N2O emissions from transportation rail electricity. and An ongoing planned improvement is to develop improved estimates of domestic waterborne fuel consumption. The Inventory estimates for residual and distillate fuel used by ships and boats is based in part on data on bunker fuel use from the U.S. Department of Commerce. Domestic fuel consumption is estimated by subtracting fuel sold for international use from the total sold in the United States. It may be possible to more accurately estimate domestic fuel use and emissions by using detailed data on marine ship activity. The feasibility of using domestic marine activity data to improve the estimates will continue to be investigated.

Given this, I'm doubtful the report measures all cargo ships internationally.

> flags of convince

<pedantry>flags of convenience</pedantry>

You bring up "public transport" as one of the emissions sources beyond people's control, without bringing up the biggest source which is under our control: cars. US per capita CO2 emissions are 20 tons/year, of which a typical passenger car is 5 tons/year. If you're worried about the carbon footprint of your stuff...it is possible to buy less stuff.

So I can find that the US has about 16 tons/year of CO2 emissions per capita. Do you have a source for how much the passenger cars contribute?

https://www.epa.gov/greenvehicles/greenhouse-gas-emissions-t...

There was a journalist in the UK that lives for 3 months, with his family, doing everything they could manage to reduce their carbon footprint, and they got it down by about 5%.

There are roughly 2 passenger cars per person in the US, so cars are about 12% of emission, but even if you had no car you’d still need to travel somehow. You’d never get your travel footprint to zero. I am not saying don’t try or don’t bother, I’m just saying firstly we are not going to solve this with public policy action. And second, sometimes there are other valid environmental issues we can focus on in our personal behaviour.

Did that journalist ever do plane trips? I recall reading that for many people that is the single biggest thing that accounts for their emissions.

Different foods have different carbon intensity. My current small apartment has a smaller utility bill than the large house I used to own. These are choices.

That's why, if you really want to limit your carbon footprint, you have to do it by conscientious consumption.

Buy less meat or no meat.

Never buy a car new. Used are more cost effective anyway.

Same goes for clothes.

Choose an electricity supplier that uses a green source of power or buys offset certificates for all the power they produce.

If your employer is going to pay to send you to a conference of your choice, pick the one that is 300 miles away over the one that is 3000 miles away.

We are already past 400ppm. Going to net 0 emmisions is not enough anymore.

We most likely need a system of solar mirrors, massive quantities of sulfur dioxide dumped into the stratosphere, ocean fertilization, and probably a lot of direct removal of carbon from the atmosphere. It's pretty ridiculous that we've let it get this far.

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