5 ms·

I highly doubt that we will have global negative emissions (CO2 capturing) within the next decades-- maybe by the end of the century. Even very rich nations ha

I highly doubt that we will have global negative emissions (CO2 capturing) within the next decades-- maybe by the end of the century. Even very rich nations have a handful of prototype plants for CO2 capture right now at best, and the budget for things like this is the first thing that gets slashed by Doge et al. If we were on track for lots of CO2 capture by 2050, we would see the beginnings already (massive investments, quickly scaling numbers of capture sites, rapid tech iteration). Fully agree with the rest of your point though. I consider CO2 emissions as basically "raising the difficulty level" for current and future humans (in a very unethical way, disproportionately affecting poor/arid/coastal nations). I'm also highly confident that human extinction from climate change is completely off the table (and I think a lot of people delude themselves into believing that scenario for no reason).

fpoling 1y ago
If electricity is sufficiently cheap it can be cheaper to capture carbon from the atmosphere for chemical industry than to use oil or coal there.
- VBprogrammer 1y ago
  Do you have any source for this extraordinary claim? It's practically a claim of perpetual motion. Carbon dioxide a tiny fraction of the atmosphere, even in concentrations which are immediately harmful to human life. At the moment it's 400 parts per million. So in order to extract 1kg of Carbon Dioxide from the atmosphere you have to pump 2500kg of air through the system. This alone makes it unlikely we can do this profitability. You then need to extract the carbon dioxide using some technique which will probably involve cooling or pressuring that volume of air. Before finally transforming carbon dioxide, a very stable chemical compound, into a reagent which is actually useful (probably carbon monoxide).
  - DesertVarnish 1y ago
    Difficult engineering problem but working from first principles suggests that the energy requirememts are not insurmountable. The roundtrip efficiency is worse than batteries but much better than photosynthesis. Terraform Industries (and others, like Synhelion) has a plausible if slightly optimistic target to be price competitive with fossil fuels for methane in the early 2030s. Some places with very cheap to extract hydrocarbons like Saudi Arabia may be able to compete for a very long time, but there are many futures where most of humanity's hydrocarbon consumption (including the ones used for the chemical industry, plastics, etc) derives from atmospheric carbon. And this can happen fast, the world (mostly China) has developed a truly massive manufacturing capacity for PV.
    - VBprogrammer 1y ago
      Terraform Industries (and others); I'd seriously consider taking a long bet that these companies turn out to be better at converting investor capital into employee salaries, for a finite period of time, than they are at converting atmospheric CO2 into natural gas. If such a technology was possible then it would be far better to start with carbon capture from existing emitters. The concentration of CO2 being easily 3 orders of magnitude higher.
      - DesertVarnish 1y ago
        For hydrocarbon synthesis, hydrogen production from electrolysis dominates the energy usage, along with driving the Sabatier process. DAC might be like 5-10%. Higher CO2 concentration is better but certainly not needed, it doesn't make or break the economics.
        VBprogrammer 1y ago
        I'm not going to argue over the numbers but any business which ignores such an obvious upside / upside scenario is not really serious about achieving economic criticality. It would allow a power plant, iron ore plant, cement producer, what have you, to make claims about their environmental credentials while simultaneously improving the efficiency of the process.
  - ben_w 1y ago
    They said "If electricity is sufficiently cheap", which is less a claim and more a tautology. Will it be that cheap? I think so, given that trees and grass etc. exist and get their carbon from the air.
    - HPsquared 1y ago
      Even with free electricity, the capital (and maintenance, consumables etc) costs of the process could easily be too high.
      - ben_w 1y ago
        I suppose that in principle that is indeed possible; in practice, trees exist and self-seed, so the limit is our own ignorance.
        overfeed 1y ago
        We are also limited the incentives to that make us cut tree for money, and not develop technologies if they are not profitable within a short time-window. We have the technology to plant more trees right now, but we aren't.
        ben_w 1y ago
        People plant loads of trees for lumber, but you're right, it's an economics question in the end. This actually means I'm also worried about something currently impossible: that when we do develop the tech sufficiently to be useful, if it's cheap enough to be profitable, nothing would seem to stop extraction. So CO2 goes down to, what, 300ppm? Pre-industrial? Ice age? Same coin, other side. We want to flip a coin and have it land on the edge. A single world government could organise to fix this either way, but as all leadership roles come with the risk of the leader being fundamentally bad, this isn't something I'd advocate for either.
        myrmidon 1y ago
  - hnaccount_rng 1y ago
    It may never be “worth” it in economic sense, but it offers a way to separate the time of “energy is used” and “energy is available”. Assuming sufficient captureable volume you could capture the emissions of a fossil power plant during the ~two weeks per year where weather is sufficiently bad. And then take the other 50 weeks to capture that carbon again. It can be completely inefficient (like sub 5% round trip efficiency) if a) we pay for it via a capacity market and b) have sufficient excess (clean) energy to run it
    - VBprogrammer 1y ago
      The idea that we'll have huge excesses of clean energy seems like wishful thinking. We may have issues with excess energy at certain times of day for sure. But intermittent excesses like that are difficult to make use of economically because of capital costs and low utilisation. A general excess would be countered by falling energy prices to the point that it's difficult to make a business case for new installations. I don't see a future where technologies which are massively inefficient reach their break even cost before other energy intensive activities or more efficient grid scale storage soak up the excess.
      - hnaccount_rng 1y ago
        Of course it seems like wishful thinking! Because that’s the historic norm. Energy was (in some way) always the limiting factor. And every time energy access got meaningfully cheaper society massively reorganised around it. And yes “energy” in general won’t be free. We still need to build the generation and distribution systems. But we reached a point where just dumping solar on all _new_ roofs rounds to essentially free (the costs are the labor and the access to qualified personnel). The exact same is currently happening to batteries. Any transformer project will be able to just integrate 4-12 hours of batteries without getting meaningfully more expensive. The same for every domestic or industry service upgrade We are not there yet. But give it another 5 years and we will. And then we are only talking about financing what little distribution system we will need (basically you only need average-sized cables not peak-sized ones) and a capacity market for backup power systems (also only for average residual demand). And those we simply cannot (efficiently) finance by a per-kWh-used charge
- throwaway2037 1y ago
  > If electricity is sufficiently cheap It never will be.
- myrmidon 1y ago
  If you actually use captured carbon for something productive like synthetic fuel (where CO2 gets re-emitted) you are kinda ruining the point though. Thats what makes this even less attractive-- those plants are expensive to build and operate and you can't even really use the product in the most obvious ways.
  - fpoling 1y ago
    This about using carbon for chemical industry.
cess11 1y ago
"Even very rich nations have a handful of prototype plants for CO2 capture right now at best, and the budget for things like this is the first thing that gets slashed by Doge et al." Might want to take a look at China, or at least what IEA writes about CCUS and the like there. https://www.chinadaily.com.cn/a/202505/09/WS681d52e5a310a04af22be44b_4.html https://www.chinadaily.com.cn/a/202505/09/WS681d52e5a310a04a...
sfn42 1y ago
The problem with carbon capture is volume. There is about 0.04% CO2 in air. So in order to remove a ton of CO2, you would need to process thousands of tons of air, depending on the efficiency of the extraction process. It's just kind of infeasible to pull the entire atmosphere through these plants. The largest one we have is called mammoth, claimed to remove 36000 tons of CO2 per year, meanwhile our emissions are measured in billions of tons per year. Like over 30 billion. We would need about 30 mammoths to get to a million tons per year, and 30,000 mammoths to get to a billion. Then multiply by another 30 and in total we would need almost a million mommoth plants just to undo what we are doing right now at the same rate. Carbon capture is like trying to empty the ocean with a bucket. How are you so confident that extinction is off the table? I've stopped following this stuff because it's depressing but last time I checked we were in dire straits and I haven't heard any good news on this front. I'm just seeing ice caps disappearing, ocean currents changing, weather changing, pretty much everything that's been predicted is now happening and it's not going to slow down any time soon.
- myrmidon 1y ago
  > How are you so confident that extinction is off the table? Because even the worst-case scenarios (=> think RCP8.5) are just not enough to get rid of us. I can totally see populous breadbasket states turning into unliveable deserts, billions of deaths from famines and heatwaves, iconic coastal cities being lost to the sea and a giant loss of biodiversity-- but I simply don't see this eradicating our species. Humans are too adaptable, and warming is invariably gonna leave too many survivable holdout regions. I think that an all-out global nuclear war would be much more threatening to humanity, and even that I'm very confident we would survive as species.
  - sfn42 1y ago
    Yeah so this is mostly just a difference of definition. When I say extinction I mean what you describe, essentially a total collapse of modern society. I don't care whether/how long a few people survive somewhere, your scenario is apocalyptic enough for me to label it an apocalypse. I also think this process is likely to trigger a new world war. When nations start collapsing there will be two possible outcomes - other nations take them in or they go to war. They won't just sit down and die. And everyone else won't be able to handle the number of refugees even if they want to.
alex_duf 1y ago
>I highly doubt that we will have global negative emissions (CO2 capturing) within the next decades Just to clarify what I wrote, I also highly doubt we'll get it at scale in the near future. We desperately need it though, as well as any other measure that will bend the trends in the right direction. This may not be the right place for this, but I'm honestly getting very anxious about our climate. Some of the data such as the temperature anomaly is showing an exponential trend. See the scariest graph I've ever seen here: https://www.nytimes.com/2025/06/26/climate/climate-heat-intensity.html https://www.nytimes.com/2025/06/26/climate/climate-heat-inte...

fpoling 1y ago

If electricity is sufficiently cheap it can be cheaper to capture carbon from the atmosphere for chemical industry than to use oil or coal there.

VBprogrammer 1y ago
Do you have any source for this extraordinary claim? It's practically a claim of perpetual motion. Carbon dioxide a tiny fraction of the atmosphere, even in concentrations which are immediately harmful to human life. At the moment it's 400 parts per million. So in order to extract 1kg of Carbon Dioxide from the atmosphere you have to pump 2500kg of air through the system. This alone makes it unlikely we can do this profitability. You then need to extract the carbon dioxide using some technique which will probably involve cooling or pressuring that volume of air. Before finally transforming carbon dioxide, a very stable chemical compound, into a reagent which is actually useful (probably carbon monoxide).
- DesertVarnish 1y ago
  Difficult engineering problem but working from first principles suggests that the energy requirememts are not insurmountable. The roundtrip efficiency is worse than batteries but much better than photosynthesis. Terraform Industries (and others, like Synhelion) has a plausible if slightly optimistic target to be price competitive with fossil fuels for methane in the early 2030s. Some places with very cheap to extract hydrocarbons like Saudi Arabia may be able to compete for a very long time, but there are many futures where most of humanity's hydrocarbon consumption (including the ones used for the chemical industry, plastics, etc) derives from atmospheric carbon. And this can happen fast, the world (mostly China) has developed a truly massive manufacturing capacity for PV.
  - VBprogrammer 1y ago
    Terraform Industries (and others); I'd seriously consider taking a long bet that these companies turn out to be better at converting investor capital into employee salaries, for a finite period of time, than they are at converting atmospheric CO2 into natural gas. If such a technology was possible then it would be far better to start with carbon capture from existing emitters. The concentration of CO2 being easily 3 orders of magnitude higher.
    - DesertVarnish 1y ago
      For hydrocarbon synthesis, hydrogen production from electrolysis dominates the energy usage, along with driving the Sabatier process. DAC might be like 5-10%. Higher CO2 concentration is better but certainly not needed, it doesn't make or break the economics.
      - VBprogrammer 1y ago
        I'm not going to argue over the numbers but any business which ignores such an obvious upside / upside scenario is not really serious about achieving economic criticality. It would allow a power plant, iron ore plant, cement producer, what have you, to make claims about their environmental credentials while simultaneously improving the efficiency of the process.
- ben_w 1y ago
  They said "If electricity is sufficiently cheap", which is less a claim and more a tautology. Will it be that cheap? I think so, given that trees and grass etc. exist and get their carbon from the air.
  - HPsquared 1y ago
    Even with free electricity, the capital (and maintenance, consumables etc) costs of the process could easily be too high.
    - ben_w 1y ago
      I suppose that in principle that is indeed possible; in practice, trees exist and self-seed, so the limit is our own ignorance.
      - overfeed 1y ago
        We are also limited the incentives to that make us cut tree for money, and not develop technologies if they are not profitable within a short time-window. We have the technology to plant more trees right now, but we aren't.
        ben_w 1y ago
        People plant loads of trees for lumber, but you're right, it's an economics question in the end. This actually means I'm also worried about something currently impossible: that when we do develop the tech sufficiently to be useful, if it's cheap enough to be profitable, nothing would seem to stop extraction. So CO2 goes down to, what, 300ppm? Pre-industrial? Ice age? Same coin, other side. We want to flip a coin and have it land on the edge. A single world government could organise to fix this either way, but as all leadership roles come with the risk of the leader being fundamentally bad, this isn't something I'd advocate for either.
        myrmidon 1y ago
- hnaccount_rng 1y ago
  It may never be “worth” it in economic sense, but it offers a way to separate the time of “energy is used” and “energy is available”. Assuming sufficient captureable volume you could capture the emissions of a fossil power plant during the ~two weeks per year where weather is sufficiently bad. And then take the other 50 weeks to capture that carbon again. It can be completely inefficient (like sub 5% round trip efficiency) if a) we pay for it via a capacity market and b) have sufficient excess (clean) energy to run it
  - VBprogrammer 1y ago
    The idea that we'll have huge excesses of clean energy seems like wishful thinking. We may have issues with excess energy at certain times of day for sure. But intermittent excesses like that are difficult to make use of economically because of capital costs and low utilisation. A general excess would be countered by falling energy prices to the point that it's difficult to make a business case for new installations. I don't see a future where technologies which are massively inefficient reach their break even cost before other energy intensive activities or more efficient grid scale storage soak up the excess.
    - hnaccount_rng 1y ago
      Of course it seems like wishful thinking! Because that’s the historic norm. Energy was (in some way) always the limiting factor. And every time energy access got meaningfully cheaper society massively reorganised around it. And yes “energy” in general won’t be free. We still need to build the generation and distribution systems. But we reached a point where just dumping solar on all _new_ roofs rounds to essentially free (the costs are the labor and the access to qualified personnel). The exact same is currently happening to batteries. Any transformer project will be able to just integrate 4-12 hours of batteries without getting meaningfully more expensive. The same for every domestic or industry service upgrade We are not there yet. But give it another 5 years and we will. And then we are only talking about financing what little distribution system we will need (basically you only need average-sized cables not peak-sized ones) and a capacity market for backup power systems (also only for average residual demand). And those we simply cannot (efficiently) finance by a per-kWh-used charge
throwaway2037 1y ago
> If electricity is sufficiently cheap It never will be.
myrmidon 1y ago
If you actually use captured carbon for something productive like synthetic fuel (where CO2 gets re-emitted) you are kinda ruining the point though. Thats what makes this even less attractive-- those plants are expensive to build and operate and you can't even really use the product in the most obvious ways.
- fpoling 1y ago
  This about using carbon for chemical industry.

cess11 1y ago

"Even very rich nations have a handful of prototype plants for CO2 capture right now at best, and the budget for things like this is the first thing that gets slashed by Doge et al." Might want to take a look at China, or at least what IEA writes about CCUS and the like there. https://www.chinadaily.com.cn/a/202505/09/WS681d52e5a310a04af22be44b_4.html https://www.chinadaily.com.cn/a/202505/09/WS681d52e5a310a04a...

sfn42 1y ago

The problem with carbon capture is volume. There is about 0.04% CO2 in air. So in order to remove a ton of CO2, you would need to process thousands of tons of air, depending on the efficiency of the extraction process. It's just kind of infeasible to pull the entire atmosphere through these plants. The largest one we have is called mammoth, claimed to remove 36000 tons of CO2 per year, meanwhile our emissions are measured in billions of tons per year. Like over 30 billion. We would need about 30 mammoths to get to a million tons per year, and 30,000 mammoths to get to a billion. Then multiply by another 30 and in total we would need almost a million mommoth plants just to undo what we are doing right now at the same rate. Carbon capture is like trying to empty the ocean with a bucket. How are you so confident that extinction is off the table? I've stopped following this stuff because it's depressing but last time I checked we were in dire straits and I haven't heard any good news on this front. I'm just seeing ice caps disappearing, ocean currents changing, weather changing, pretty much everything that's been predicted is now happening and it's not going to slow down any time soon.

myrmidon 1y ago
> How are you so confident that extinction is off the table? Because even the worst-case scenarios (=> think RCP8.5) are just not enough to get rid of us. I can totally see populous breadbasket states turning into unliveable deserts, billions of deaths from famines and heatwaves, iconic coastal cities being lost to the sea and a giant loss of biodiversity-- but I simply don't see this eradicating our species. Humans are too adaptable, and warming is invariably gonna leave too many survivable holdout regions. I think that an all-out global nuclear war would be much more threatening to humanity, and even that I'm very confident we would survive as species.
- sfn42 1y ago
  Yeah so this is mostly just a difference of definition. When I say extinction I mean what you describe, essentially a total collapse of modern society. I don't care whether/how long a few people survive somewhere, your scenario is apocalyptic enough for me to label it an apocalypse. I also think this process is likely to trigger a new world war. When nations start collapsing there will be two possible outcomes - other nations take them in or they go to war. They won't just sit down and die. And everyone else won't be able to handle the number of refugees even if they want to.

alex_duf 1y ago

>I highly doubt that we will have global negative emissions (CO2 capturing) within the next decades Just to clarify what I wrote, I also highly doubt we'll get it at scale in the near future. We desperately need it though, as well as any other measure that will bend the trends in the right direction. This may not be the right place for this, but I'm honestly getting very anxious about our climate. Some of the data such as the temperature anomaly is showing an exponential trend. See the scariest graph I've ever seen here: https://www.nytimes.com/2025/06/26/climate/climate-heat-intensity.html https://www.nytimes.com/2025/06/26/climate/climate-heat-inte...