5 ms·

One not very well known fact is that even if we stop emissions today, the elevated CO₂ levels will remain for many centuries. They way I think/hope we can fix

One not very well known fact is that even if we stop emissions today, the elevated CO₂ levels will remain for many centuries. They way I think/hope we can fix this is two parts: 1. The only way I think you can get rid of the excess CO₂ at scale is to permanently sequester it underground. The oil/gas industry can cheaply deposit huge amounts of gas there. The unsolved problem is extracting enough CO₂ from the atmosphere at reasonable cost. People are working on that, but it will probably be decades before it's is approaching practicality. Which is why we need to do this in the meantime: 2. Spray the stratosphere with SO₂. This reflects some some sunlight and cools the planet. It sounds scary, but is actually safe: https://makesunsets.com/pages/new-faq https://makesunsets.com/pages/new-faq

michaelbarton 2mo ago
Only safe if we never stop doing it once we start I think? Otherwise it ends up being worse than if we had not done it in the first place
- 0x_rs 2mo ago
  It's been reduced before through cracking down on pollution. The results are directly suspected to be responsible for an increase in warming rate, both locally and worldwide. The only way in which it would be necessary to keep releasing it, and in increasingly higher quantities, is only if no other measure or action is taken, which is obviously not the intended goal: its purpose is to make up for the damage already done that will linger for longer than anyone currently alive. The emission reductions in our simulations correspond closely to the emissions reductions realized in East Asia over the period 2010–2023, in magnitude and geographical location. This allows us to put our results in the context of the recent uptick in the observed rate of global mean surface warming. Here, we find that emissions reductions in East Asia have contributed up to 0.05 °C/decade since 2010, explaining a large fraction of the observed increase of 0.06 °C/decade over the same period, after filtering out the effects of interannual variability. (from https://www.nature.com/articles/s43247-025-02527-3 https://www.nature.com/articles/s43247-025-02527-3)
ndsipa_pomu 2mo ago
Stratospheric aerosol injection hasn't been tested at any kind of scale, so we do not know whether it would be harmful (e.g. acid rain) or not. It would also be very expensive, so it's not really a practical solution at the moment. It may pan out, but stating "actually safe" is not yet known.
- BurningFrog 2mo ago
  The Mt Pinatubo volcanic eruption in 1991 actually did inject huge amounts of SO₂ to the stratosphere, and it disappeared over the next few years. While it remained, northern hemisphere temperatures lowered by ~0.5°C. USGS report: https://pubs.usgs.gov/pinatubo/self/ https://pubs.usgs.gov/pinatubo/self/ Since the stratosphere is far above the rain cycle, it's very hard to imagine a mechanism whereby this could produce acid rain, and even if it did, acid rain is a much smaller problem than global warming.
  - 0x000xca0xfe 2mo ago
    > acid rain is a much smaller problem than global warming. In fact it used to be a common occurence during the heavy industrial pollution in the 20th century. So much that after the pollution stopped, farmers had to start applying sulphur to their fields as nutrients for some crops (I learned about this after unsuccessfully trying to grow tomatoes in alkaline soil).
    - nozzlegear 2mo ago
      > In fact it used to be a common occurence during the heavy industrial pollution in the 20th century. I remember watching news reports about acid rain in the 90s and being terrified that any ominous rain cloud might be full of acid rain which would melt away my town and family.
    - deleted 2mo ago
      [deleted]
  - ndsipa_pomu 2mo ago
    Yes, volcanoes are relevant data points, but that's also very different to proposed methods of seeding. It does raise the question of whether someone will decide to set off bombs in fault-lines to try and set off an eruption - I recall Trump asking why hurricanes couldn't be disrupted by the early use of bombs. > acid rain is a much smaller problem than global warming Possibly, but acid rain can devastate marine ecosystems and cause issues with soil quality, so I'm not convinced that we can just hand-wave it away. I can foresee greedy capitalists rubbing their hands together over being paid to seed SO2 into the stratosphere and then being paid to clean it up too. There's probably a lot of money to be made selling clean air if we can pollute the atmosphere enough to cause health problems for people.
nozzlegear 2mo ago
> 2. Spray the stratosphere with SO₂. This reflects some some sunlight and cools the planet. It sounds scary, but is actually safe: [...] The Pina2bo strategy! https://www.goodreads.com/book/show/57094295-termination-shock https://www.goodreads.com/book/show/57094295-termination-sho...
tda 2mo ago
Best would be to capture CO2, and then solidify the carbon to a compact stable stable state by taking away the oxygen. Then we have a highly concentrated pure carbon form that we can just bury underground. Or add some hydrogen and get this liquid state that we can pump back into those empty underground reservoirs. But maybe we should stop taking it out in the first place...
- palata 2mo ago
  We get energy by extracting oil and burning it. It takes a lot more energy to do the reverse. We already cannot stop burning oil today because the economy would implode. I don't think that it is reasonable to think that not only we could stop burning oil entirely, AND at the same time produce more energy than we got from oil just for extracting the CO2 from the atmosphere... And the reality is even worse than that, because on top of all that* we would need more energy to... live. It's important people understand that we cannot extract the CO2 once it's out there. It's practically impossible, period.
- arw0n 2mo ago
  You are talking about trees...
  - obruchez 2mo ago
    Trees that disappear in huge fires more and more often, unfortunately.
    - tejohnso 2mo ago
      One of the many reinforcing feedbacks that contribute to making global warming such a difficult problem.
potsandpans 2mo ago
> It sounds scary, but is actually safe Posted by the account, BurningFrog. You can't make this shit up. Forgive me if I do not take "making sunsets" as a credible source of information. There's a body of research that covers existential risks associated with sai and srm: - https://www.sciencedirect.com/science/article/abs/pii/S0016328717301131 https://www.sciencedirect.com/science/article/abs/pii/S00163... - https://www.frontiersin.org/journals/climate/articles/10.3389/fclim.2021.720312/full https://www.frontiersin.org/journals/climate/articles/10.338... - https://agupubs.onlinelibrary.wiley.com/doi/10.1002/2017EF000735 https://agupubs.onlinelibrary.wiley.com/doi/10.1002/2017EF00... Further from an actual credible source: https://www.unep.org/resources/report/Solar-Radiation-Modification-research-deployment https://www.unep.org/resources/report/Solar-Radiation-Modifi... > While there is a growing body of literature and advanced modelling on the topic, which has been developing for many years, there is very little evidence or research on the risks and impacts of SRM. The report outlines these limitations in the evidence base. UNEP is concerned that while the scientific literature shows that SRM, and stratospheric aerosol injection specifically, can cool the globe, there is a dearth of data on the risks and impacts. For technologies that can alter the chemistry of the stratosphere, the world needs much more information to support decision-making. No, it is not "safe" by any measure.
- frm88 2mo ago
  It also reduces efficiency of solar energy generation by 5-15%, so we had better build out additional energy supply to account for that. https://www.science-gate.com/IJAAS/Articles/2025/2025-12-01/1021833ijaas202501001.pdf https://www.science-gate.com/IJAAS/Articles/2025/2025-12-01/...
palata 2mo ago
> The only way I think you can get rid of the excess CO₂ at scale [...] The unsolved problem is extracting You answered it yourself: it's not possible to get rid of the excess CO2. Think about conservation of energy: we extracted energy by burning stuff and producing CO2. We cannot revert that with less energy than we extracted from doing it in the first place. > It sounds scary, but is actually safe Famous last words.
- patapong 2mo ago
  I agree that it's not easy, but we could in theory use solar energy, which is abundant and cheap. I.e. We can use different energy than the one we got out of the fossil fuels we burned.
  - Henchman21 2mo ago
    What are we going to replace concrete with?
  - palata 2mo ago
    > I.e. We can use different energy than the one we got out of the fossil fuels we burned. We're talking about using more energy than the one we got from the fossil fuels we burned, right? So that means that on top of replacing fossil fuels with renewables, we would need to more than double it in order to remove CO2 from the atmosphere. This, in itself, is impossible. Already we won't be able to replace fossil fuels entirely, we will just end up with less energy in total. We most certainly won't end up with twice as much. And that's assuming that we could extract the CO2 from the atmosphere with close to the amount of energy we got by burning it in the first place. Which is wrong. CO2 in the atmosphere is actually very costly to extract in terms of energy. It's not that it's not easy. It's practically impossible.
    - margalabargala 2mo ago
      So the neat thing is that this isn't at all true. The total annual CO2 budget of the earth is tremendous; less than 5% of CO2 emissions each year into the atmosphere are from humans. Volcanism, photosynthesis, and other natural sources outweigh humans by far. In numbers, ballpark 730gigatons from natural sources and about 30gt from humans. If you look at the amount the CO2 levels increase each year in the atmosphere, you'll find that they net increase by 16gt per year or so. Implying that if we ceased all human CO2 emissions, the atmospheric levels would start recovering at around half the rate they're currently increasing.
kybernetikos 2mo ago
> The only way I think you can get rid of the excess CO₂ at scale is to permanently sequester it underground. The oil/gas industry can cheaply deposit huge amounts of gas there. The unsolved problem is extracting enough CO₂ from the atmosphere at reasonable cost. The bigger unsolved problem is how to get this paid for.
teravor 2mo ago
> Spray the stratosphere with SO₂ it will probably be more effective to introduce additives to jet fuel that form aerosols. something like sodium.
- pvaldes 2mo ago
  Look, finally a good, decent and new idea. If we could remove lead from gas, and put addblue on every car in 5 years, we surely could build better plane engines via increasing the regulatory laws pressure and change the type of fuel used. Raining salt over terrestrial ecosystems is not the way, but over the ocean, may work. You have my applause teravor.
deleted 2mo ago
[deleted]

michaelbarton 2mo ago

Only safe if we never stop doing it once we start I think? Otherwise it ends up being worse than if we had not done it in the first place

0x_rs 2mo ago
It's been reduced before through cracking down on pollution. The results are directly suspected to be responsible for an increase in warming rate, both locally and worldwide. The only way in which it would be necessary to keep releasing it, and in increasingly higher quantities, is only if no other measure or action is taken, which is obviously not the intended goal: its purpose is to make up for the damage already done that will linger for longer than anyone currently alive. The emission reductions in our simulations correspond closely to the emissions reductions realized in East Asia over the period 2010–2023, in magnitude and geographical location. This allows us to put our results in the context of the recent uptick in the observed rate of global mean surface warming. Here, we find that emissions reductions in East Asia have contributed up to 0.05 °C/decade since 2010, explaining a large fraction of the observed increase of 0.06 °C/decade over the same period, after filtering out the effects of interannual variability. (from https://www.nature.com/articles/s43247-025-02527-3 https://www.nature.com/articles/s43247-025-02527-3)

ndsipa_pomu 2mo ago

Stratospheric aerosol injection hasn't been tested at any kind of scale, so we do not know whether it would be harmful (e.g. acid rain) or not. It would also be very expensive, so it's not really a practical solution at the moment. It may pan out, but stating "actually safe" is not yet known.

BurningFrog 2mo ago
The Mt Pinatubo volcanic eruption in 1991 actually did inject huge amounts of SO₂ to the stratosphere, and it disappeared over the next few years. While it remained, northern hemisphere temperatures lowered by ~0.5°C. USGS report: https://pubs.usgs.gov/pinatubo/self/ https://pubs.usgs.gov/pinatubo/self/ Since the stratosphere is far above the rain cycle, it's very hard to imagine a mechanism whereby this could produce acid rain, and even if it did, acid rain is a much smaller problem than global warming.
- 0x000xca0xfe 2mo ago
  > acid rain is a much smaller problem than global warming. In fact it used to be a common occurence during the heavy industrial pollution in the 20th century. So much that after the pollution stopped, farmers had to start applying sulphur to their fields as nutrients for some crops (I learned about this after unsuccessfully trying to grow tomatoes in alkaline soil).
  - nozzlegear 2mo ago
    > In fact it used to be a common occurence during the heavy industrial pollution in the 20th century. I remember watching news reports about acid rain in the 90s and being terrified that any ominous rain cloud might be full of acid rain which would melt away my town and family.
  - deleted 2mo ago
    [deleted]
- ndsipa_pomu 2mo ago
  Yes, volcanoes are relevant data points, but that's also very different to proposed methods of seeding. It does raise the question of whether someone will decide to set off bombs in fault-lines to try and set off an eruption - I recall Trump asking why hurricanes couldn't be disrupted by the early use of bombs. > acid rain is a much smaller problem than global warming Possibly, but acid rain can devastate marine ecosystems and cause issues with soil quality, so I'm not convinced that we can just hand-wave it away. I can foresee greedy capitalists rubbing their hands together over being paid to seed SO2 into the stratosphere and then being paid to clean it up too. There's probably a lot of money to be made selling clean air if we can pollute the atmosphere enough to cause health problems for people.

nozzlegear 2mo ago

> 2. Spray the stratosphere with SO₂. This reflects some some sunlight and cools the planet. It sounds scary, but is actually safe: [...] The Pina2bo strategy! https://www.goodreads.com/book/show/57094295-termination-shock https://www.goodreads.com/book/show/57094295-termination-sho...

tda 2mo ago

Best would be to capture CO2, and then solidify the carbon to a compact stable stable state by taking away the oxygen. Then we have a highly concentrated pure carbon form that we can just bury underground. Or add some hydrogen and get this liquid state that we can pump back into those empty underground reservoirs. But maybe we should stop taking it out in the first place...

palata 2mo ago
We get energy by extracting oil and burning it. It takes a lot more energy to do the reverse. We already cannot stop burning oil today because the economy would implode. I don't think that it is reasonable to think that not only we could stop burning oil entirely, AND at the same time produce more energy than we got from oil just for extracting the CO2 from the atmosphere... And the reality is even worse than that, because on top of all that* we would need more energy to... live. It's important people understand that we cannot extract the CO2 once it's out there. It's practically impossible, period.
arw0n 2mo ago
You are talking about trees...
- obruchez 2mo ago
  Trees that disappear in huge fires more and more often, unfortunately.
  - tejohnso 2mo ago
    One of the many reinforcing feedbacks that contribute to making global warming such a difficult problem.

potsandpans 2mo ago

> It sounds scary, but is actually safe Posted by the account, BurningFrog. You can't make this shit up. Forgive me if I do not take "making sunsets" as a credible source of information. There's a body of research that covers existential risks associated with sai and srm: - https://www.sciencedirect.com/science/article/abs/pii/S0016328717301131 https://www.sciencedirect.com/science/article/abs/pii/S00163... - https://www.frontiersin.org/journals/climate/articles/10.3389/fclim.2021.720312/full https://www.frontiersin.org/journals/climate/articles/10.338... - https://agupubs.onlinelibrary.wiley.com/doi/10.1002/2017EF000735 https://agupubs.onlinelibrary.wiley.com/doi/10.1002/2017EF00... Further from an actual credible source: https://www.unep.org/resources/report/Solar-Radiation-Modification-research-deployment https://www.unep.org/resources/report/Solar-Radiation-Modifi... > While there is a growing body of literature and advanced modelling on the topic, which has been developing for many years, there is very little evidence or research on the risks and impacts of SRM. The report outlines these limitations in the evidence base. UNEP is concerned that while the scientific literature shows that SRM, and stratospheric aerosol injection specifically, can cool the globe, there is a dearth of data on the risks and impacts. For technologies that can alter the chemistry of the stratosphere, the world needs much more information to support decision-making. No, it is not "safe" by any measure.

frm88 2mo ago
It also reduces efficiency of solar energy generation by 5-15%, so we had better build out additional energy supply to account for that. https://www.science-gate.com/IJAAS/Articles/2025/2025-12-01/1021833ijaas202501001.pdf https://www.science-gate.com/IJAAS/Articles/2025/2025-12-01/...

palata 2mo ago

> The only way I think you can get rid of the excess CO₂ at scale [...] The unsolved problem is extracting You answered it yourself: it's not possible to get rid of the excess CO2. Think about conservation of energy: we extracted energy by burning stuff and producing CO2. We cannot revert that with less energy than we extracted from doing it in the first place. > It sounds scary, but is actually safe Famous last words.

patapong 2mo ago
I agree that it's not easy, but we could in theory use solar energy, which is abundant and cheap. I.e. We can use different energy than the one we got out of the fossil fuels we burned.
- Henchman21 2mo ago
  What are we going to replace concrete with?
- palata 2mo ago
  > I.e. We can use different energy than the one we got out of the fossil fuels we burned. We're talking about using more energy than the one we got from the fossil fuels we burned, right? So that means that on top of replacing fossil fuels with renewables, we would need to more than double it in order to remove CO2 from the atmosphere. This, in itself, is impossible. Already we won't be able to replace fossil fuels entirely, we will just end up with less energy in total. We most certainly won't end up with twice as much. And that's assuming that we could extract the CO2 from the atmosphere with close to the amount of energy we got by burning it in the first place. Which is wrong. CO2 in the atmosphere is actually very costly to extract in terms of energy. It's not that it's not easy. It's practically impossible.
  - margalabargala 2mo ago
    So the neat thing is that this isn't at all true. The total annual CO2 budget of the earth is tremendous; less than 5% of CO2 emissions each year into the atmosphere are from humans. Volcanism, photosynthesis, and other natural sources outweigh humans by far. In numbers, ballpark 730gigatons from natural sources and about 30gt from humans. If you look at the amount the CO2 levels increase each year in the atmosphere, you'll find that they net increase by 16gt per year or so. Implying that if we ceased all human CO2 emissions, the atmospheric levels would start recovering at around half the rate they're currently increasing.

kybernetikos 2mo ago

> The only way I think you can get rid of the excess CO₂ at scale is to permanently sequester it underground. The oil/gas industry can cheaply deposit huge amounts of gas there. The unsolved problem is extracting enough CO₂ from the atmosphere at reasonable cost. The bigger unsolved problem is how to get this paid for.

teravor 2mo ago

> Spray the stratosphere with SO₂ it will probably be more effective to introduce additives to jet fuel that form aerosols. something like sodium.

pvaldes 2mo ago
Look, finally a good, decent and new idea. If we could remove lead from gas, and put addblue on every car in 5 years, we surely could build better plane engines via increasing the regulatory laws pressure and change the type of fuel used. Raining salt over terrestrial ecosystems is not the way, but over the ocean, may work. You have my applause teravor.

deleted 2mo ago

[deleted]