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The impact of direct air carbon capture on climate change

152 points by _Microft 7y ago

itcrowd 7y ago
Very well written and balanced article. Thanks for sharing these insights. Looking forward to another "tiny corner" of your explorations of these technologies!
- _Microft 7y ago
  It's not mine but if you're interested in more of the author, follow @michael_nielsen on Twitter.
gersh 7y ago
I'd like to know the land use requirements of direct air capture technology. Will it use enormous amounts of land? What is currently on that land? Will this entail scalability issues?
- DennisP 7y ago
  An estimate I've seen repeatedly is that they'll take about 1/1000 as much land area as the same carbon capture with trees.
ForHackernews 7y ago
Does direct air carbon capture at scale even exist? Is there plausible reason to think it will exist in the next few decades? The whole article seems like "If nuclear fusion cost $100 per MWHr, but if it only cost $10/MWHr..."
jarvist 7y ago
I'm not sure if this article hammers home the key point: extracting carbon from the air always takes more energy that was gained by burning the fossil fuel to make that carbon. This is inevitable due to the entropy cost of de-mixing CO2 from the air, and from the limited efficiencies of thermal power generation (~33-40% for a coal power plant, perhaps 20% in an internal combustion engine), and limited efficiency of the carbon capture technology. So it only makes sense to spend energy on sucking CO2 out of the atmosphere, once you've already de-carbonised everything which you possibly can. Maybe it has a future role (>2050? >2100?) to start using excess low-carbon energy to take CO2 levels back to their pre-industrial level, or to constantly offset hard-to-decarbonise technologies such as air travel.
- ForHackernews 7y ago
  > Maybe it has a future role (>2050? >2100?) It absolutely must, or else it's basically already too late: https://www.vox.com/2016/10/4/13118594/2-degrees-no-more-fossil-fuels https://www.vox.com/2016/10/4/13118594/2-degrees-no-more-fos... > This image should terrify you. It should be on billboards. > As you can see, in either scenario, global emissions must peak and begin declining immediately. For a medium chance to avoid 1.5 degrees, the world has to zero out net carbon emissions by 2050 or so — for a good chance of avoiding 2 degrees, by around 2065. > After that, emissions have to go negative. Humanity has to start burying a lot more carbon than it throws up into the atmosphere.... Thus far, most demonstration plants of any size attaching CCS to fossil fuel facilities have been over-budget disasters. What if we can’t rely on it? What if it never pans out? > If we really want to avoid 1.5 degrees, and we can’t rely on large-scale carbon sequestration, then the global community has to zero out its carbon emissions by 2026. (emphasis mine)
  - aidenn0 7y ago
    My dad sees articles like this and he'll just say that maybe the damage needed to prevent warming is worse than the damage that will be done by the warming.
    - AnthonyMouse 7y ago
      The cost to ordinary people would actually be relatively minor. You buy an electric car instead of a gasoline one. The average new car price in the US is ~$36,000. A new Nissan Leaf starts below $30,000, Model 3 only a little more than that. Replace coal with alternatives. We can do at least as well as nuclear, which is barely any more expensive than coal has been. Best case is that storage gets a lot cheaper than it is and then the price of electricity goes down from the historical norm. Capture could cost as little as zero. Renewables inherently have to build over-capacity to compensate for intermittency, but that means there are days when they generate more power than there is demand. Use the rest for carbon capture and it's free. The real "cost" to fixing it, and the big lobby against it, is that the oil and coal companies would take a nosedive. Literally trillions of dollars in lost revenue. It moves to alternatives. It isn't economic damage, it's displacement. But the specific people who own the oil and coal reserves stand to lose their shirts, and these are not people lacking in political influence. Everything you hear about the high cost -- it's only really a cost to them. To you it's just an upgrade to electric. But we still have to actually do it. A carbon tax so that people do all buy electric cars and stop burning coal. It's a thing we can do but not a thing we have done yet.
tathougies 7y ago
Good analysis, but fails to take into account the storage costs of whatever CO2 is sequestered (or the potential to offset those costs by selling the CO2 to whatever industry uses them).
- henryfjordan 7y ago
  The article does take storage cost into account (although it does kinda waive it away): > If this impression is correct then the cost of capturing CO2 is likely to either dominate or in worst case be comparable to the cost of storage and utilization. Still, a more detailed analysis would be careful about this costing
- mmanfrin 7y ago
  > storage costs of whatever CO2 is sequestered CO2 is not spent uranium.
  - pjc50 7y ago
    No, but you do have to keep it somewhere where it won't leak back into the atmosphere again any time soon. Which means deep underground.
basicplus2 7y ago
Would love to know how many Trees/Algea farms/plants generally would need to do the job Also growing plants and converting to fuel is exceedingly cheap for diesel And before anyone gets worried about food prices going up.. it takes a surprisingly small amount of land mass to cover currect sneeds in energy, sorry no references no time..
btilly 7y ago
I would have liked to see https://projectvesta.org/ https://projectvesta.org/ commented on in the article. They claim to be able to sequester carbon by scattering olivine rock in an active and warm coast. The cost of the rock is $25/ton now, with the prospect of $10/ton in the future. Plus whatever it costs to break it up and scatter it. That makes it at an interesting price point if it works as advertised. Even more interesting to me is that the absorption happens in the water. Meaning that it can counteract ocean acidification near the coral reefs that are the most vulnerable.
- throwawayhhakdl 7y ago
  I would aggressively vote and promote a us presidential candidate who stated they would negotiate an arrangement to do this for financial compensation on coastal equator countries- and failing that, a hostile military invasion to force it upon them. Probably no need for the latter, but having it on the table makes the former easier to negotiate. This process could release deadly nickel into the water. It probably would harm the coral reefs more than help... but I really feel like much of the ocean is pretty f*ed longer term anyway. Also the countries most poised to do this are the ones most at risk from climate change both in terms of heat, tidal forces, and horrible storms. I feel it would be a powerful platform. It makes an optimistic message out of an otherwise negative concept- and it makes America the hero saving the world. Who wouldn’t vote for that?
  - pjc50 7y ago
    > and failing that, a hostile military invasion to force it upon them. Eco-fascism! I mean, once you're willing to murder people to reduce carbon emissions, there are simpler ways to do it. But make sure you've got suitable carbon offsets for the invasion and the crematoriums. > optimistic message "Good news: America is going to improve the world at gunpoint again!"
    - virmundi 7y ago
      I know people won’t like it, but the alternative is a Mad Max world. We’re told the whole planet will be either an ocean or a desert unless we return to the Stone Age. Therefore we need to follow the Georgia monument and reduce the global population to 500 million. Anything less than the total dissolution of human rights in the name of environmental protection is a death sentence anyways. At least we can use the benevolence of democracy to pick winners and losers.
scarygliders 7y ago
Here goes for further downvotes... The entire edifice of this "human caused climate change" hypothesis rests on the premise that carbon dioxide is /the/ control knob for this planet's temperature. There is zero proof that this is true. Zero. So if I were you, I'd be very, very cautious before going ahead with capturing CO2, by any method. It's way too early for this sort of thing. Vastly more research is required before taking a potentially disastrous decision to try to reduce the amount of CO2 - a gas which Earthly vegetation /needs/ in order to survive!
- pipermerriam 7y ago
  Can you provide anything beyond conjecture that there is any merit to what you've stated? My understanding is that the effects of CO2 as a greenhouse gas are pretty well understood at this point.
  - scarygliders 7y ago
    I can only ask that you read some Stuff From The Other Side Of The Argument... http://www.drroyspencer.com/ http://www.drroyspencer.com/ is a good start on that. I'm already being downvoted on here - proof that there are a substantial number of HN users who have Made Up Their Minds on this, and simply do not want to even consider that they have been bamboozled by various interested parties. I realise that no one likes to either admit they've been fooled by someone/a group of people, or simply that their view of the world around them is simply wrong - still, no reason to use HN's downvoting as a weapon against those who would otherwise try to post a contrary view. Still, it's fascinating to be downvoted simply for offering a contrary opinion. As an interesting but connected sidenote: I've noticed on here that numerous HN submissions which tend towards CO2 demonization get upvoted and are filled with the Convinced, whereas the various articles I have submitted which tend to question this either get zero attention or are downvoted to obliviion. Whatever, and so be it.
    - throwawayhhakdl 7y ago
      Link looks a lot of garbage cherry picking of individual bad or flawed actors and arguments as misleading rhetoric that fallaciously implies the underlying belief is incorrect... as per usual...
whytaka 7y ago
Michael Nielsen, the author, also wrote a multi-part intro to neural networks (http://neuralnetworksanddeeplearning.com http://neuralnetworksanddeeplearning.com) which really cleared up for me the inner-workings and mathematics of machine learning quickly but without skimping on details. I'm very excited to read what he has to say here.
dv_dt 7y ago
If you're going to continue to burn fossil fuels, it seems better to burn it in a plant that inherently captures the carbon then trying to wrangle it back after it's release. The interesting part of the Allam cycle for power generation is that supercritical co2 is the working fluid for the turbine, and when you burn the fuel it increases the mass in the closed circuit. Both the size and the efficiency of the plant also purportedly improve with the Allam cycle too. https://en.wikipedia.org/wiki/Allam_power_cycle https://en.wikipedia.org/wiki/Allam_power_cycle https://www.netpower.com/technology/ https://www.netpower.com/technology/
- pfdietz 7y ago
  That would be true, if the power plant has high capacity factor, and if it stationary, and if it is located near a place where the CO2 can be sequestered. But if you (say) have peaking turbines that are intended to take over when renewables or short term storage are not available, they may have very low capacity factor. It could be economical to have them release the CO2 into the atmosphere, then steadily scrub that CO2 back out again, especially if that scrubbing could be done in a location with extremely cheap solar energy (like, say, Chile).
  - dv_dt 7y ago
    I'm for pursuing both options really. There are likely solution areas where both would be a win. And we really know not enough about the end direct cost of either until sufficient numbers are built out - and we should build out both to at least 10x what the prototypes do. The real problems are governmental policy, and then financial policy to get the attention and scaling going on any of these solutions.
jacknews 7y ago
Fast-growing trees, which are then burnt to charcoal (and some energy), which is then put in the soil as biochar. Could be very cheap/low-tech and at the same time improve soils.
- ph0rque 7y ago
  Or, buried wholesale as part of a Hügelkultur.
  - jacknews 7y ago
    yes this could be even cheaper, though I'm not sure if perhaps the co2 is released quicker as the trees decompose- charcoal can keep the carbon locked up for centuries. Either way, these methods greatly improve the land-use efficiency of growing trees for carbon capture/storage, as it is stored in the soil over many years, not only in the living trees. "putting coal back in the ground" as it were.
WalterBright 7y ago
Just plant trees. They're cheap, solar powered, and convert CO2 to building materials.
- pfdietz 7y ago
  They use too much land.
  - vanniv 7y ago
    That's why you cut them down and build stuff out of them! But, yes, in time we can probably build something more efficient.
  - ahartman00 7y ago
    To be specific, arable land. Not all land is fertile. And as the old saying goes, they arent making any more :) Then there is the time aspect. They dont grow as fast as one would like. "The need for arable land to feed human populations and the needs of wildlife have been in tension for millennia. One can look to Easter Island to see what the end game of man's resource overexploitation can lead to. Currently more than 1.4 billion hectares of land have been committed to agriculture. As human populations swell, especially in lower latitudes, even more forests will be cut, surface water and aquifers tapped, fertilizers applied, and pesticides broadcasted—all of which threaten insects and other biodiversity either directly (e.g., land conversion and pesticide exposure) or indirectly (e.g., water use and nitrogen and phosphorus pollution). Savannahs, prairies, and grasslands, with their deep fertile soils, lend themselves to immediate use for crop and pasturelands, and as consequence are collectively among the most threatened biomes on the planet. The clearing of tropical forests for farming and pastureland is happening at alarming rates and will have especially grave consequences for insect species diversity" https://www.sciencedirect.com/topics/earth-and-planetary-sciences/arable-land https://www.sciencedirect.com/topics/earth-and-planetary-sci...
- adrianN 7y ago
  Start by protecting existing forests. We're still losing rainforests ever more rapidly.
spodek 7y ago
Not a word about the most effective, cheapest strategy: reduce emissions? Most Americans could reduce their emissions by 75% while improving their standard of living by buying less junk, wearing a sweater in the winter, eating more healthy, and other low hanging fruit that will make them more active, healthy, connected to their communities, etc. Reduce consumption by half. There, I just saved us $300 million. How is reduction not our top priority and activity??
- shartshooter 7y ago
  Because it’s also the least effective strategy. The reality is getting nearly everyone to change their behavior just isn’t gonna happen. Even if everyone in America went vegan, showered once a day and biked everywhere wouldn’t change much with impoverished countries coming out of the third world. If you can’t get them to change then it doesn’t really matter. Big problems require big, comprehensive solutions. For that you need government to function effectively regulate, make climate bills countries can stick to. We already have the tools we need to get climate change turned around but we don’t have the political will.
  - seminatl 7y ago
    Wait. Does the average American shower more than once daily? Is water consumption/heating for showering even a measurable component of GHG emissions?
  - _Microft 7y ago
    Not at all, we need to cut back on emissions everywhere. That also applies to Americans, who emit 3-4 times more per capita than what is sustainable.
  - triceratops 7y ago
    > Even if everyone in America went vegan > we don’t have the political will. Something tells me that achieving the first would more easily lead to the second. For a politician whose constituency is mostly vegans, their work on climate change will determine whether they keep their seat. If their constituents are pickup-truck-driving, McMansion-owning suburbanites, it's not going to be a priority. I recognize that getting everyone to go vegan isn't possible or maybe even desirable. But let's not pretend that willing personal sacrifice isn't at least part of the solution.
cagenut 7y ago
I really like the way the author tries to ballpark orders of magnitude and compare against known-budgetary-things for frames of reference. That said, talk of 10/tonne is pure fantasy, the real band is between 100 and 1000, so the analysis here is a full decimal place naive (of course, IMHO). Just to contribute, another americanized version of the numbers: $100/tonne of a carbon tax works out to about $0.87 per gallon of gasoline. So if you assume carbon engineerings pilot plant estimates turn out to be right but on the high-end, at $232/tonne that's an almost perfect $2/gallon. Which raises an interesting point to ponder... if anyone were capable of extracting carbon from the atmosphere at under $200/tonne... then all the oil companies would almost instantly switch to only building those plants. Why fight for drilling rights and production share agreement terms when air is everywhere.
KludgyPerl 7y ago
Agriculture can do DAC: https://terraton.indigoag.com/ https://terraton.indigoag.com/
ph0rque 7y ago
You can do it to the tune of $15/person/year: https://automicrofarm.com/blog/2019/03/solving-climate-change-with-trees.html https://automicrofarm.com/blog/2019/03/solving-climate-chang...
bamboozled 7y ago
It's really nice to even see this discussed, I've been really interested in this topic. It's true, at some stage we're going to have to reduce the carbon we've already injected into the atmosphere, so why not get started now. It's amazing how little funding this has received. I'd actually be interested in paying for this like any other utility, as electricity prices get cheaper from renewable energy, I'd be happy to pay a carbon capture bill to survive and breathe cleaner air. I'd also hope this would be a temporary thing as we completely transfer away from fossil fuels. Pay to clean up some of my own mess,makes sense.
leh_chmp 7y ago
This argument is so naïve that I had to create an HN account (downvote ready comment for dissing HN commenters). Do note that I am not dissing the author. He did claim a lack of expertise, but I am sad to see the comments trying to analyze the directly presented facts than being detail driven. E.g. I saw some reference to Allum's process of reusing CO2. What it skips is the fact that it barely effects efficiency, but certainly sees that is better than excusing. I still don't understand how $ among is used to measure environmental impact is a relationship people can think is easy measure. Maybe because short term thinking is rewarded better, hence the success of capitalism (I'm not pro/anti, but that's the root of the philosophy). I am assuming that people understand that Carbon capture doesn't resolve environmental changes. It simply offsets a part of it - the global warming aspect. A LOT of impact is straight up coming from pollution/contamination of water and soil, recurring costs of restructuring landscapes, causing earthquakes to floods and terraforming from receding coastlines, destruction of habitats, leading from contaminated species to complete destruction is food sources. The cascading effect of environmental damages is like paying a loan. As humans we are known to be overconfident of "I can fix it". But remind me historically when THAT had worked? Almost in all cases, it had been "I can forget this". Except in this case, I think if we had to expend that sort of money to "solve the problem", then we might as well just find a new planet to squander. In 50 years, we would have spent trillions of dollars unanimously and probably got to Mars [Edit] typos
SomewhatLikely 7y ago
Don't vehicles emit other greenhouse gases too? Or would the carbon cover the overwhelming majority of effect?
dwoozle 7y ago
If carbon capture is good then why do they encourage composting? Shouldn’t we be taking that organic material and burying it somewhere?
- baq 7y ago
  we should, preferably in shut down coal mines where the carbon came from, but that takes time, money and fuel.
LessDmesg 7y ago
Tell me again, why are we fighting the harmless gas carbon dioxide instead of air pollution (sulphurous, nitrous oxides, lead etc)?
- pinkfoot 7y ago
  Again: https://www.ipcc.ch/ https://www.ipcc.ch/ Go read. Come back when you find errors in the reports.
  - LessDmesg 7y ago
    But that's a biased source of information. The IPCC depends on donations from Western governments for its existence, and Western governments are fatally dependent on inventing reasons for new taxation due to their exorbitant amounts of sovereign debt. Is there any unbiased source on this extraordinary claim that the tiny CO2 emissions humanity makes actually control climate?
    - pinkfoot 7y ago
      So no reading for you then.
      - LessDmesg 7y ago
        So there are no unbiased sources on why carbon dioxide is evil? You do understand that CO2-hate is like a religion, don't you? And I have in fact gone to the IPCC's site and skimmed over a report. It was filled with phrases like "could reach ... by 2100" and "is projected to reach...". So no hard science, just empty speculation.
        adrianN 7y ago
        You're fundamentally misunderstanding the term "hard science".
    - imtringued 7y ago
godmode2019 7y ago
Dear friends. I had to make an account for this one. This whole thread is based on a premise that co2 is the problem. I have been researching climate change stuff for awhile so forgive me if I skip anything. We are all smart people and have pretty good bullshit detectors. First visit the 97% paper https://iopscience.iop.org/article/10.1088/1748-9326/8/2/024024 https://iopscience.iop.org/article/10.1088/1748-9326/8/2/024... Please take 10mins and read that with a open mind. When I first read it I was shock at how badly it was written. I'm use to reading investment documents if someone showed me that and told paper to invest in their conclusion I would laugh them out of the room. I don't have time to point by point break it down. But its pretty clear. Just read it. Second all the studies on greenhouse gases are studies of correlation not causation. Which I was also stocked to find out. Co2 is a wonder chemical, most of the plants we know evolved in a high co2 environment. The co2 levels are shockingly low right now. When we talk about carbon capture we have to consider what is the optimal levels of carbon. I believe its 150pp we are around 300pp - 400pp depending on where you are. If co2 drops below 150pp for too long all life on earth will die. Are we sure we want to grow fungi or bacteria that rapidly eats carbon. Do we really want to crush special rocks and spread them around? Just like the fellows who thought it would be a good idea to engineer mozzies in south American to be hyper breeder and have a gene that causes off spring to die, or something. Turns out nature prevails and they made a killing machine. The road to hell is pathed with good intentions Co2, check out the light spectrum analysis of co2 compared to other greenhouse gases. Check out the data on the magnetosphere and how changes effects protection from cosmic rays. Check out mean reversal. We are in snowball earth phase of the cycle right now. Humans have had a new good runs of about 15,000 years in between long cold winters of 75,000+ years. We happen to be in one of those periods now, things started to warm up 15,000 years ago warm enough that we could breed , grow things , build things. Everything always returns to the mean. Which is cold. Cold is bad, things die when its cold. Things love the warmth. Look into sea level rise. Our whole history has been running from the raising sea. Its been swallowing our cities or towns. The Australian aboriginals walked most of the way to Australia. The sea level was very low, that was not that long ago. 7plants, which require a minimum of 150 ppm to survive 50k - 75,000 years ago. In my country they have almost made it illegal to have a fireplace. Fire.. The most human thing I can think of. Banning fire.. We humans want slaves , we have always wanted slaves. Its the most efficient system to place everyone in slavery and you and you friends won't be. Can you notice the slowly raising voice that children are bad for the planet, you and your terrible western life style are killing the planet. Banning children is the next thing after they win the climate stuff. I have looked at every point of global warming caused by humans and everything is so twisted. Wikipedia for example straight up removes science that speaks against global warming. Or they will word it in a way that makes it too completed to understand for normal people. All of google search results are artificial as well. Its actually really hard to find the information you have to go to google scholar and actually read the papers its easy to tell the activist from the science. Activists lead with their opinion and try find information to confirm it. Science poses a question runs tests publishes the results without twisting it. When something is twisted it is because they don't like the result, why would you not like the result of science? Doesn't make sense. All science, real science leads us closer to the truth. Not digging deeper into falsehoods. Climate models are all really bad simulations , you think the smartest people in the world are working on climate models? No, they are not. Climate science is mostly activists. Its like the business studies major. A little bit of everything but not enough of anything. Geology, astronomy, physics, biology, mathematics. These people we can still trust. If you don't believe me go read the difference in tone between climate science and a real science. Climate science people largely quote each other, word things in a PR friendly way, want to come to a consensus. Real scientists want to prove each other wrong. Go against the grain, question everything, believe nothing. Proof what can be tested. Disregard what can not be tested. Unfalsifiable assertion is faith the pillar of religion. What piece of evidence would disprove something, nothing can disprove human caused global warming. It's untestable it's faith. When a say do your research if you do anything read the 97% of scientists document. When you actually read it and see what they did to mess with the numbers you will be shocked that this passed for science. The major drivers of global temp are as follows Jetstream Ocean tides - elnino ect Sun CME Magnetic strength Solar cycles. Longer term stuff, tilt, orbit, ect but those are pretty well understood by the climate morals. The other stuff their morals have no idea how to input that data. Its a complex system. When other planets have similar trends as earth you can be sure that we didn't cause that trend as well.
40four 7y ago
I've been interested in these types of technologies lateley. >that many people are extremely pessimistic about climate change. They can’t imagine any solution – often, they become mesmerized by what appears to be an insoluble collective action problem – and fall into fatalistic despair. More and more, I find this description matches my thoughts on climate change. I'm really beginning to think the problem might require building carbon capture solutions on a huge scale. We might have to engineer our way out, because it doesn't appear we are slowing down emissions fast enough.
- DanTheManPR 7y ago
  We are geoengineering already, so we are going to have to deliberately geoengineer our way out of the problem.
  - 40four 7y ago
    >we are going to have to deliberately geoengineer our way out of the problem Agreed, I'm really starting to think this will be the only way.
- topkai22 7y ago
  I'm totally with you. Reducing carbon intensity is possible (and almost easy) up to a point, but once you've converted 80-90% of the power grid to renewable sources and electrified most transportation there is still significant carbon emissions occurring for high value operations, like air transportation. Plus we still have to deal with the elevated levels we are at today. Having viable large scale carbon capture technology, gives us another advantage though- It gives us a really solid economic foundation for pricing those remaining carbon emitting operations. Entities can just regulate or tax carbon emissions at that point, and let the market figure out what activities and operations are still worth emitting for.
acollins1331 7y ago
Carbon capture is the dumbest and most expensive way to move forward. It would be cheaper to just turn every coal plant into a solar farm then it would be to capture the carbon out of the air so why even bother. Oh yeah, corporate interests.
- sinuhe69 7y ago
  True. Especially if nature already has the best direct carbon capture technology since hundreds millions of years for free: trees!
  - ncmncm 7y ago
    Plants convert at most 2% of incident light into chemical energy, and spend only a fraction of that binding carbon. Trees are cheap but need a lot of space and water. People are cutting down forests because they want to use the space for something else. Ocean surface algae also collect solar power and carbon, and there is little demand for ocean surface for other uses. Algae are limited by available trace minerals -- cheap ones.
    - acollins1331 7y ago
      Iron seeding of the oceans to increase producer activity is currently being done but on large enough scales to sequester enough CO2 to make a difference it's basically impossible.
      - ncmncm 7y ago
        Where is it being done, and by whom? The only one ongoing I know of is Sahara dust being (naturally) blown out to the Atlantic ocean. Otherwise, just talk. Somebody who did an experiment had his results suppressed, crudely, with a false narrative promoted in its place. Why that was seen as necessary, and how it happened, seem even more interesting than the experiment.
hypertexthero 7y ago
We need to stop callin it “climate change” and start calling it ”climate crisis”.
iron0013 7y ago
You know, I'm not sure I really need to hear from any more non-experts thinking out loud anymore. We've had enough of that. I want to hear from experts giving their carefully considered views.
leemck 7y ago
OK to shout Eureka when you figure this out: I have a website where I explore the idea of "not emitting fossil fuel CO2." www.lowco2america.com Instead of thinking in terms of "cost of extracting CO2" I have sort of stumbled on the idea of "recapitalizing America around social systems that do not emit CO2." My scheme has a payment of $394 per metric ton of CO2 not emitted. The payment from govt. funds is a prompt no bank account required electronic transfer payment. What it can purchase is a continuing free share of the electricity generated by the workplace parking lot, or an electric car, where the car is free is provided the driver carries 2 or 3 workplace commute riders. The car runs with an average load of 1 driver and 2 or 3 riders. The payment can pay for other things or be redeemed for cash, optionally. The ancient Chinese Tao Te Ching poem Verse 80 describes a happy society that might sound a little bit like an America that figures out how to live well with 2 mt per person CO2 emissions, maybe in 40 years?
leemck 7y ago
To rephrase this article: The impact of direct air carbon capture will require enormous input of energy or enormous tonnage of materials such as limestone. Another approach to reducing the human contribution to atmospheric carbon dioxide is to have each person adopt a low CO2 emission life style. Just like a massive carbon capture technology, enabling individuals to adopt a low CO2 emission lifestyle is not a free proposition. How much to pay an individual to implement a specific low CO2 life style? Gasoline (the high emission variety 19.6 lb per gallon) at $3.50 a gallon produces a metric ton of CO2 for $393. More detail at:https://www.lowco2america.com/2018/10/gasoline-co2-in-air-what-are-some-of.html https://www.lowco2america.com/2018/10/gasoline-co2-in-air-wh...

152 points by _Microft 7y ago

Very well written and balanced article. Thanks for sharing these insights. Looking forward to another "tiny corner" of your explorations of these technologies!

_Microft 7y ago
It's not mine but if you're interested in more of the author, follow @michael_nielsen on Twitter.

gersh 7y ago

I'd like to know the land use requirements of direct air capture technology. Will it use enormous amounts of land? What is currently on that land? Will this entail scalability issues?

DennisP 7y ago
An estimate I've seen repeatedly is that they'll take about 1/1000 as much land area as the same carbon capture with trees.

ForHackernews 7y ago

Does direct air carbon capture at scale even exist? Is there plausible reason to think it will exist in the next few decades? The whole article seems like "If nuclear fusion cost $100 per MWHr, but if it only cost $10/MWHr..."

jarvist 7y ago

I'm not sure if this article hammers home the key point: extracting carbon from the air always takes more energy that was gained by burning the fossil fuel to make that carbon. This is inevitable due to the entropy cost of de-mixing CO2 from the air, and from the limited efficiencies of thermal power generation (~33-40% for a coal power plant, perhaps 20% in an internal combustion engine), and limited efficiency of the carbon capture technology. So it only makes sense to spend energy on sucking CO2 out of the atmosphere, once you've already de-carbonised everything which you possibly can. Maybe it has a future role (>2050? >2100?) to start using excess low-carbon energy to take CO2 levels back to their pre-industrial level, or to constantly offset hard-to-decarbonise technologies such as air travel.

ForHackernews 7y ago
> Maybe it has a future role (>2050? >2100?) It absolutely must, or else it's basically already too late: https://www.vox.com/2016/10/4/13118594/2-degrees-no-more-fossil-fuels https://www.vox.com/2016/10/4/13118594/2-degrees-no-more-fos... > This image should terrify you. It should be on billboards. > As you can see, in either scenario, global emissions must peak and begin declining immediately. For a medium chance to avoid 1.5 degrees, the world has to zero out net carbon emissions by 2050 or so — for a good chance of avoiding 2 degrees, by around 2065. > After that, emissions have to go negative. Humanity has to start burying a lot more carbon than it throws up into the atmosphere.... Thus far, most demonstration plants of any size attaching CCS to fossil fuel facilities have been over-budget disasters. What if we can’t rely on it? What if it never pans out? > If we really want to avoid 1.5 degrees, and we can’t rely on large-scale carbon sequestration, then the global community has to zero out its carbon emissions by 2026. (emphasis mine)
- aidenn0 7y ago
  My dad sees articles like this and he'll just say that maybe the damage needed to prevent warming is worse than the damage that will be done by the warming.
  - AnthonyMouse 7y ago
    The cost to ordinary people would actually be relatively minor. You buy an electric car instead of a gasoline one. The average new car price in the US is ~$36,000. A new Nissan Leaf starts below $30,000, Model 3 only a little more than that. Replace coal with alternatives. We can do at least as well as nuclear, which is barely any more expensive than coal has been. Best case is that storage gets a lot cheaper than it is and then the price of electricity goes down from the historical norm. Capture could cost as little as zero. Renewables inherently have to build over-capacity to compensate for intermittency, but that means there are days when they generate more power than there is demand. Use the rest for carbon capture and it's free. The real "cost" to fixing it, and the big lobby against it, is that the oil and coal companies would take a nosedive. Literally trillions of dollars in lost revenue. It moves to alternatives. It isn't economic damage, it's displacement. But the specific people who own the oil and coal reserves stand to lose their shirts, and these are not people lacking in political influence. Everything you hear about the high cost -- it's only really a cost to them. To you it's just an upgrade to electric. But we still have to actually do it. A carbon tax so that people do all buy electric cars and stop burning coal. It's a thing we can do but not a thing we have done yet.

tathougies 7y ago

Good analysis, but fails to take into account the storage costs of whatever CO2 is sequestered (or the potential to offset those costs by selling the CO2 to whatever industry uses them).

henryfjordan 7y ago
The article does take storage cost into account (although it does kinda waive it away): > If this impression is correct then the cost of capturing CO2 is likely to either dominate or in worst case be comparable to the cost of storage and utilization. Still, a more detailed analysis would be careful about this costing
mmanfrin 7y ago
> storage costs of whatever CO2 is sequestered CO2 is not spent uranium.
- pjc50 7y ago
  No, but you do have to keep it somewhere where it won't leak back into the atmosphere again any time soon. Which means deep underground.

basicplus2 7y ago

Would love to know how many Trees/Algea farms/plants generally would need to do the job Also growing plants and converting to fuel is exceedingly cheap for diesel And before anyone gets worried about food prices going up.. it takes a surprisingly small amount of land mass to cover currect sneeds in energy, sorry no references no time..

btilly 7y ago

I would have liked to see https://projectvesta.org/ https://projectvesta.org/ commented on in the article. They claim to be able to sequester carbon by scattering olivine rock in an active and warm coast. The cost of the rock is $25/ton now, with the prospect of $10/ton in the future. Plus whatever it costs to break it up and scatter it. That makes it at an interesting price point if it works as advertised. Even more interesting to me is that the absorption happens in the water. Meaning that it can counteract ocean acidification near the coral reefs that are the most vulnerable.

throwawayhhakdl 7y ago
I would aggressively vote and promote a us presidential candidate who stated they would negotiate an arrangement to do this for financial compensation on coastal equator countries- and failing that, a hostile military invasion to force it upon them. Probably no need for the latter, but having it on the table makes the former easier to negotiate. This process could release deadly nickel into the water. It probably would harm the coral reefs more than help... but I really feel like much of the ocean is pretty f*ed longer term anyway. Also the countries most poised to do this are the ones most at risk from climate change both in terms of heat, tidal forces, and horrible storms. I feel it would be a powerful platform. It makes an optimistic message out of an otherwise negative concept- and it makes America the hero saving the world. Who wouldn’t vote for that?
- pjc50 7y ago
  > and failing that, a hostile military invasion to force it upon them. Eco-fascism! I mean, once you're willing to murder people to reduce carbon emissions, there are simpler ways to do it. But make sure you've got suitable carbon offsets for the invasion and the crematoriums. > optimistic message "Good news: America is going to improve the world at gunpoint again!"
  - virmundi 7y ago
    I know people won’t like it, but the alternative is a Mad Max world. We’re told the whole planet will be either an ocean or a desert unless we return to the Stone Age. Therefore we need to follow the Georgia monument and reduce the global population to 500 million. Anything less than the total dissolution of human rights in the name of environmental protection is a death sentence anyways. At least we can use the benevolence of democracy to pick winners and losers.

scarygliders 7y ago

Here goes for further downvotes... The entire edifice of this "human caused climate change" hypothesis rests on the premise that carbon dioxide is /the/ control knob for this planet's temperature. There is zero proof that this is true. Zero. So if I were you, I'd be very, very cautious before going ahead with capturing CO2, by any method. It's way too early for this sort of thing. Vastly more research is required before taking a potentially disastrous decision to try to reduce the amount of CO2 - a gas which Earthly vegetation /needs/ in order to survive!

pipermerriam 7y ago
Can you provide anything beyond conjecture that there is any merit to what you've stated? My understanding is that the effects of CO2 as a greenhouse gas are pretty well understood at this point.
- scarygliders 7y ago
  I can only ask that you read some Stuff From The Other Side Of The Argument... http://www.drroyspencer.com/ http://www.drroyspencer.com/ is a good start on that. I'm already being downvoted on here - proof that there are a substantial number of HN users who have Made Up Their Minds on this, and simply do not want to even consider that they have been bamboozled by various interested parties. I realise that no one likes to either admit they've been fooled by someone/a group of people, or simply that their view of the world around them is simply wrong - still, no reason to use HN's downvoting as a weapon against those who would otherwise try to post a contrary view. Still, it's fascinating to be downvoted simply for offering a contrary opinion. As an interesting but connected sidenote: I've noticed on here that numerous HN submissions which tend towards CO2 demonization get upvoted and are filled with the Convinced, whereas the various articles I have submitted which tend to question this either get zero attention or are downvoted to obliviion. Whatever, and so be it.
  - throwawayhhakdl 7y ago
    Link looks a lot of garbage cherry picking of individual bad or flawed actors and arguments as misleading rhetoric that fallaciously implies the underlying belief is incorrect... as per usual...

whytaka 7y ago

Michael Nielsen, the author, also wrote a multi-part intro to neural networks (http://neuralnetworksanddeeplearning.com http://neuralnetworksanddeeplearning.com) which really cleared up for me the inner-workings and mathematics of machine learning quickly but without skimping on details. I'm very excited to read what he has to say here.

dv_dt 7y ago

If you're going to continue to burn fossil fuels, it seems better to burn it in a plant that inherently captures the carbon then trying to wrangle it back after it's release. The interesting part of the Allam cycle for power generation is that supercritical co2 is the working fluid for the turbine, and when you burn the fuel it increases the mass in the closed circuit. Both the size and the efficiency of the plant also purportedly improve with the Allam cycle too. https://en.wikipedia.org/wiki/Allam_power_cycle https://en.wikipedia.org/wiki/Allam_power_cycle https://www.netpower.com/technology/ https://www.netpower.com/technology/

pfdietz 7y ago
That would be true, if the power plant has high capacity factor, and if it stationary, and if it is located near a place where the CO2 can be sequestered. But if you (say) have peaking turbines that are intended to take over when renewables or short term storage are not available, they may have very low capacity factor. It could be economical to have them release the CO2 into the atmosphere, then steadily scrub that CO2 back out again, especially if that scrubbing could be done in a location with extremely cheap solar energy (like, say, Chile).
- dv_dt 7y ago
  I'm for pursuing both options really. There are likely solution areas where both would be a win. And we really know not enough about the end direct cost of either until sufficient numbers are built out - and we should build out both to at least 10x what the prototypes do. The real problems are governmental policy, and then financial policy to get the attention and scaling going on any of these solutions.

jacknews 7y ago

Fast-growing trees, which are then burnt to charcoal (and some energy), which is then put in the soil as biochar. Could be very cheap/low-tech and at the same time improve soils.

ph0rque 7y ago
Or, buried wholesale as part of a Hügelkultur.
- jacknews 7y ago
  yes this could be even cheaper, though I'm not sure if perhaps the co2 is released quicker as the trees decompose- charcoal can keep the carbon locked up for centuries. Either way, these methods greatly improve the land-use efficiency of growing trees for carbon capture/storage, as it is stored in the soil over many years, not only in the living trees. "putting coal back in the ground" as it were.

WalterBright 7y ago

Just plant trees. They're cheap, solar powered, and convert CO2 to building materials.

pfdietz 7y ago
They use too much land.
- vanniv 7y ago
  That's why you cut them down and build stuff out of them! But, yes, in time we can probably build something more efficient.
- ahartman00 7y ago
  To be specific, arable land. Not all land is fertile. And as the old saying goes, they arent making any more :) Then there is the time aspect. They dont grow as fast as one would like. "The need for arable land to feed human populations and the needs of wildlife have been in tension for millennia. One can look to Easter Island to see what the end game of man's resource overexploitation can lead to. Currently more than 1.4 billion hectares of land have been committed to agriculture. As human populations swell, especially in lower latitudes, even more forests will be cut, surface water and aquifers tapped, fertilizers applied, and pesticides broadcasted—all of which threaten insects and other biodiversity either directly (e.g., land conversion and pesticide exposure) or indirectly (e.g., water use and nitrogen and phosphorus pollution). Savannahs, prairies, and grasslands, with their deep fertile soils, lend themselves to immediate use for crop and pasturelands, and as consequence are collectively among the most threatened biomes on the planet. The clearing of tropical forests for farming and pastureland is happening at alarming rates and will have especially grave consequences for insect species diversity" https://www.sciencedirect.com/topics/earth-and-planetary-sciences/arable-land https://www.sciencedirect.com/topics/earth-and-planetary-sci...
adrianN 7y ago
Start by protecting existing forests. We're still losing rainforests ever more rapidly.

spodek 7y ago

Not a word about the most effective, cheapest strategy: reduce emissions? Most Americans could reduce their emissions by 75% while improving their standard of living by buying less junk, wearing a sweater in the winter, eating more healthy, and other low hanging fruit that will make them more active, healthy, connected to their communities, etc. Reduce consumption by half. There, I just saved us $300 million. How is reduction not our top priority and activity??

shartshooter 7y ago
Because it’s also the least effective strategy. The reality is getting nearly everyone to change their behavior just isn’t gonna happen. Even if everyone in America went vegan, showered once a day and biked everywhere wouldn’t change much with impoverished countries coming out of the third world. If you can’t get them to change then it doesn’t really matter. Big problems require big, comprehensive solutions. For that you need government to function effectively regulate, make climate bills countries can stick to. We already have the tools we need to get climate change turned around but we don’t have the political will.
- seminatl 7y ago
  Wait. Does the average American shower more than once daily? Is water consumption/heating for showering even a measurable component of GHG emissions?
- _Microft 7y ago
  Not at all, we need to cut back on emissions everywhere. That also applies to Americans, who emit 3-4 times more per capita than what is sustainable.
- triceratops 7y ago
  > Even if everyone in America went vegan > we don’t have the political will. Something tells me that achieving the first would more easily lead to the second. For a politician whose constituency is mostly vegans, their work on climate change will determine whether they keep their seat. If their constituents are pickup-truck-driving, McMansion-owning suburbanites, it's not going to be a priority. I recognize that getting everyone to go vegan isn't possible or maybe even desirable. But let's not pretend that willing personal sacrifice isn't at least part of the solution.

cagenut 7y ago

I really like the way the author tries to ballpark orders of magnitude and compare against known-budgetary-things for frames of reference. That said, talk of 10/tonne is pure fantasy, the real band is between 100 and 1000, so the analysis here is a full decimal place naive (of course, IMHO). Just to contribute, another americanized version of the numbers: $100/tonne of a carbon tax works out to about $0.87 per gallon of gasoline. So if you assume carbon engineerings pilot plant estimates turn out to be right but on the high-end, at $232/tonne that's an almost perfect $2/gallon. Which raises an interesting point to ponder... if anyone were capable of extracting carbon from the atmosphere at under $200/tonne... then all the oil companies would almost instantly switch to only building those plants. Why fight for drilling rights and production share agreement terms when air is everywhere.

KludgyPerl 7y ago

Agriculture can do DAC: https://terraton.indigoag.com/ https://terraton.indigoag.com/

ph0rque 7y ago

You can do it to the tune of $15/person/year: https://automicrofarm.com/blog/2019/03/solving-climate-change-with-trees.html https://automicrofarm.com/blog/2019/03/solving-climate-chang...

bamboozled 7y ago

It's really nice to even see this discussed, I've been really interested in this topic. It's true, at some stage we're going to have to reduce the carbon we've already injected into the atmosphere, so why not get started now. It's amazing how little funding this has received. I'd actually be interested in paying for this like any other utility, as electricity prices get cheaper from renewable energy, I'd be happy to pay a carbon capture bill to survive and breathe cleaner air. I'd also hope this would be a temporary thing as we completely transfer away from fossil fuels. Pay to clean up some of my own mess,makes sense.

leh_chmp 7y ago

This argument is so naïve that I had to create an HN account (downvote ready comment for dissing HN commenters). Do note that I am not dissing the author. He did claim a lack of expertise, but I am sad to see the comments trying to analyze the directly presented facts than being detail driven. E.g. I saw some reference to Allum's process of reusing CO2. What it skips is the fact that it barely effects efficiency, but certainly sees that is better than excusing. I still don't understand how $ among is used to measure environmental impact is a relationship people can think is easy measure. Maybe because short term thinking is rewarded better, hence the success of capitalism (I'm not pro/anti, but that's the root of the philosophy). I am assuming that people understand that Carbon capture doesn't resolve environmental changes. It simply offsets a part of it - the global warming aspect. A LOT of impact is straight up coming from pollution/contamination of water and soil, recurring costs of restructuring landscapes, causing earthquakes to floods and terraforming from receding coastlines, destruction of habitats, leading from contaminated species to complete destruction is food sources. The cascading effect of environmental damages is like paying a loan. As humans we are known to be overconfident of "I can fix it". But remind me historically when THAT had worked? Almost in all cases, it had been "I can forget this". Except in this case, I think if we had to expend that sort of money to "solve the problem", then we might as well just find a new planet to squander. In 50 years, we would have spent trillions of dollars unanimously and probably got to Mars [Edit] typos

SomewhatLikely 7y ago

Don't vehicles emit other greenhouse gases too? Or would the carbon cover the overwhelming majority of effect?

dwoozle 7y ago

If carbon capture is good then why do they encourage composting? Shouldn’t we be taking that organic material and burying it somewhere?

baq 7y ago
we should, preferably in shut down coal mines where the carbon came from, but that takes time, money and fuel.

LessDmesg 7y ago

Tell me again, why are we fighting the harmless gas carbon dioxide instead of air pollution (sulphurous, nitrous oxides, lead etc)?

pinkfoot 7y ago
Again: https://www.ipcc.ch/ https://www.ipcc.ch/ Go read. Come back when you find errors in the reports.
- LessDmesg 7y ago
  But that's a biased source of information. The IPCC depends on donations from Western governments for its existence, and Western governments are fatally dependent on inventing reasons for new taxation due to their exorbitant amounts of sovereign debt. Is there any unbiased source on this extraordinary claim that the tiny CO2 emissions humanity makes actually control climate?
  - pinkfoot 7y ago
    So no reading for you then.
    - LessDmesg 7y ago
      So there are no unbiased sources on why carbon dioxide is evil? You do understand that CO2-hate is like a religion, don't you? And I have in fact gone to the IPCC's site and skimmed over a report. It was filled with phrases like "could reach ... by 2100" and "is projected to reach...". So no hard science, just empty speculation.
      - adrianN 7y ago
        You're fundamentally misunderstanding the term "hard science".
  - imtringued 7y ago

godmode2019 7y ago

Dear friends. I had to make an account for this one. This whole thread is based on a premise that co2 is the problem. I have been researching climate change stuff for awhile so forgive me if I skip anything. We are all smart people and have pretty good bullshit detectors. First visit the 97% paper https://iopscience.iop.org/article/10.1088/1748-9326/8/2/024024 https://iopscience.iop.org/article/10.1088/1748-9326/8/2/024... Please take 10mins and read that with a open mind. When I first read it I was shock at how badly it was written. I'm use to reading investment documents if someone showed me that and told paper to invest in their conclusion I would laugh them out of the room. I don't have time to point by point break it down. But its pretty clear. Just read it. Second all the studies on greenhouse gases are studies of correlation not causation. Which I was also stocked to find out. Co2 is a wonder chemical, most of the plants we know evolved in a high co2 environment. The co2 levels are shockingly low right now. When we talk about carbon capture we have to consider what is the optimal levels of carbon. I believe its 150pp we are around 300pp - 400pp depending on where you are. If co2 drops below 150pp for too long all life on earth will die. Are we sure we want to grow fungi or bacteria that rapidly eats carbon. Do we really want to crush special rocks and spread them around? Just like the fellows who thought it would be a good idea to engineer mozzies in south American to be hyper breeder and have a gene that causes off spring to die, or something. Turns out nature prevails and they made a killing machine. The road to hell is pathed with good intentions Co2, check out the light spectrum analysis of co2 compared to other greenhouse gases. Check out the data on the magnetosphere and how changes effects protection from cosmic rays. Check out mean reversal. We are in snowball earth phase of the cycle right now. Humans have had a new good runs of about 15,000 years in between long cold winters of 75,000+ years. We happen to be in one of those periods now, things started to warm up 15,000 years ago warm enough that we could breed , grow things , build things. Everything always returns to the mean. Which is cold. Cold is bad, things die when its cold. Things love the warmth. Look into sea level rise. Our whole history has been running from the raising sea. Its been swallowing our cities or towns. The Australian aboriginals walked most of the way to Australia. The sea level was very low, that was not that long ago. 7plants, which require a minimum of 150 ppm to survive 50k - 75,000 years ago. In my country they have almost made it illegal to have a fireplace. Fire.. The most human thing I can think of. Banning fire.. We humans want slaves , we have always wanted slaves. Its the most efficient system to place everyone in slavery and you and you friends won't be. Can you notice the slowly raising voice that children are bad for the planet, you and your terrible western life style are killing the planet. Banning children is the next thing after they win the climate stuff. I have looked at every point of global warming caused by humans and everything is so twisted. Wikipedia for example straight up removes science that speaks against global warming. Or they will word it in a way that makes it too completed to understand for normal people. All of google search results are artificial as well. Its actually really hard to find the information you have to go to google scholar and actually read the papers its easy to tell the activist from the science. Activists lead with their opinion and try find information to confirm it. Science poses a question runs tests publishes the results without twisting it. When something is twisted it is because they don't like the result, why would you not like the result of science? Doesn't make sense. All science, real science leads us closer to the truth. Not digging deeper into falsehoods. Climate models are all really bad simulations , you think the smartest people in the world are working on climate models? No, they are not. Climate science is mostly activists. Its like the business studies major. A little bit of everything but not enough of anything. Geology, astronomy, physics, biology, mathematics. These people we can still trust. If you don't believe me go read the difference in tone between climate science and a real science. Climate science people largely quote each other, word things in a PR friendly way, want to come to a consensus. Real scientists want to prove each other wrong. Go against the grain, question everything, believe nothing. Proof what can be tested. Disregard what can not be tested. Unfalsifiable assertion is faith the pillar of religion. What piece of evidence would disprove something, nothing can disprove human caused global warming. It's untestable it's faith. When a say do your research if you do anything read the 97% of scientists document. When you actually read it and see what they did to mess with the numbers you will be shocked that this passed for science. The major drivers of global temp are as follows Jetstream Ocean tides - elnino ect Sun CME Magnetic strength Solar cycles. Longer term stuff, tilt, orbit, ect but those are pretty well understood by the climate morals. The other stuff their morals have no idea how to input that data. Its a complex system. When other planets have similar trends as earth you can be sure that we didn't cause that trend as well.

40four 7y ago

I've been interested in these types of technologies lateley. >that many people are extremely pessimistic about climate change. They can’t imagine any solution – often, they become mesmerized by what appears to be an insoluble collective action problem – and fall into fatalistic despair. More and more, I find this description matches my thoughts on climate change. I'm really beginning to think the problem might require building carbon capture solutions on a huge scale. We might have to engineer our way out, because it doesn't appear we are slowing down emissions fast enough.

DanTheManPR 7y ago
We are geoengineering already, so we are going to have to deliberately geoengineer our way out of the problem.
- 40four 7y ago
  >we are going to have to deliberately geoengineer our way out of the problem Agreed, I'm really starting to think this will be the only way.
topkai22 7y ago
I'm totally with you. Reducing carbon intensity is possible (and almost easy) up to a point, but once you've converted 80-90% of the power grid to renewable sources and electrified most transportation there is still significant carbon emissions occurring for high value operations, like air transportation. Plus we still have to deal with the elevated levels we are at today. Having viable large scale carbon capture technology, gives us another advantage though- It gives us a really solid economic foundation for pricing those remaining carbon emitting operations. Entities can just regulate or tax carbon emissions at that point, and let the market figure out what activities and operations are still worth emitting for.

acollins1331 7y ago

Carbon capture is the dumbest and most expensive way to move forward. It would be cheaper to just turn every coal plant into a solar farm then it would be to capture the carbon out of the air so why even bother. Oh yeah, corporate interests.

sinuhe69 7y ago
True. Especially if nature already has the best direct carbon capture technology since hundreds millions of years for free: trees!
- ncmncm 7y ago
  Plants convert at most 2% of incident light into chemical energy, and spend only a fraction of that binding carbon. Trees are cheap but need a lot of space and water. People are cutting down forests because they want to use the space for something else. Ocean surface algae also collect solar power and carbon, and there is little demand for ocean surface for other uses. Algae are limited by available trace minerals -- cheap ones.
  - acollins1331 7y ago
    Iron seeding of the oceans to increase producer activity is currently being done but on large enough scales to sequester enough CO2 to make a difference it's basically impossible.
    - ncmncm 7y ago
      Where is it being done, and by whom? The only one ongoing I know of is Sahara dust being (naturally) blown out to the Atlantic ocean. Otherwise, just talk. Somebody who did an experiment had his results suppressed, crudely, with a false narrative promoted in its place. Why that was seen as necessary, and how it happened, seem even more interesting than the experiment.

hypertexthero 7y ago

We need to stop callin it “climate change” and start calling it ”climate crisis”.

iron0013 7y ago

You know, I'm not sure I really need to hear from any more non-experts thinking out loud anymore. We've had enough of that. I want to hear from experts giving their carefully considered views.

leemck 7y ago

OK to shout Eureka when you figure this out: I have a website where I explore the idea of "not emitting fossil fuel CO2." www.lowco2america.com Instead of thinking in terms of "cost of extracting CO2" I have sort of stumbled on the idea of "recapitalizing America around social systems that do not emit CO2." My scheme has a payment of $394 per metric ton of CO2 not emitted. The payment from govt. funds is a prompt no bank account required electronic transfer payment. What it can purchase is a continuing free share of the electricity generated by the workplace parking lot, or an electric car, where the car is free is provided the driver carries 2 or 3 workplace commute riders. The car runs with an average load of 1 driver and 2 or 3 riders. The payment can pay for other things or be redeemed for cash, optionally. The ancient Chinese Tao Te Ching poem Verse 80 describes a happy society that might sound a little bit like an America that figures out how to live well with 2 mt per person CO2 emissions, maybe in 40 years?

leemck 7y ago

To rephrase this article: The impact of direct air carbon capture will require enormous input of energy or enormous tonnage of materials such as limestone. Another approach to reducing the human contribution to atmospheric carbon dioxide is to have each person adopt a low CO2 emission life style. Just like a massive carbon capture technology, enabling individuals to adopt a low CO2 emission lifestyle is not a free proposition. How much to pay an individual to implement a specific low CO2 life style? Gasoline (the high emission variety 19.6 lb per gallon) at $3.50 a gallon produces a metric ton of CO2 for $393. More detail at:https://www.lowco2america.com/2018/10/gasoline-co2-in-air-what-are-some-of.html https://www.lowco2america.com/2018/10/gasoline-co2-in-air-wh...