| ▲ | BurningFrog 3 days ago |
| 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 |
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| ▲ | palata 2 days ago | parent | next [-] |
| > 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. |
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| ▲ | jdjfjdkdkd 2 days ago | parent | next [-] | | 1. There is abundant energy on the earth 1kW per sq MTR from the sun.
2. The ocean absorbs a large portion of the CO2 emitted
3. Phytoplankton can eat carbon in the ocean and they use the sun's energy to do it... What they lack is iron. | |
| ▲ | patapong 2 days ago | parent | prev | next [-] | | 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. | | |
| ▲ | palata 2 days ago | parent | next [-] | | > 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 2 days ago | parent | next [-] | | 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. | | |
| ▲ | Maxatar 2 days ago | parent | next [-] | | This is an absurd statement. Lets use bank accounts instead of CO2 to point out the absurdity. Imagine every year a company makes $730,000 in revenue but spends $730,000 on various expenses. Its bank balance doesnt change because the income and expenses cancel out. Now suppose the company starts receiving an additional $30,000 every year while its expenses stay the same. At the end of each year, its bank balance increases by $30,000. By your logic, someone could argue: "That extra $30,000 can't be responsible for the growing bank balance because it's less than 5% of the company's total annual cash flow of $760,000." That's obviously nonsense. The bank balance grows *entirely because of the net imbalance*, not because the extra income is a large fraction of the gross cash flowing through the account. The carbon cycle works the same way. Natural emissions and natural uptake are both enormous and are approximately in balance. That 730 gigatons of CO2 released by natural sources has a corresponding 730 gigatons of CO2 capture from natural sinks. Its human emissions of CO2 that are the extra deposit that creates an ongoing imbalance, and that's why atmospheric CO2 continues to rise. Also photosynthesis is not a source of CO2, on the contrary it's one of, if not the biggest carbon sink, reclaiming a significant portion of that 730 gigatons of CO2 released by volcanos and other sources. | | |
| ▲ | margalabargala 2 days ago | parent [-] | | > The bank balance grows entirely because of the net imbalance Yes, this is my whole point. You wrote a long condescending comment accusing me of being a climate denier that fully agrees with me. My point is that the actual amount of atmospheric increase per year is less than the amount humans put into the atmosphere per year, so 1) obviously humans are responsible for CC, and 2) could stop it at any time by dropping emissions below the amount the atmospheric increase amount. | | |
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| ▲ | abandonliberty 2 days ago | parent | prev | next [-] | | It's unclear which message you're trying to convey, but your math checks out. The net CO2 impact of natural processes is -19Gt/yr. Humans add +37G/yr for a net +18Gt. If we stopped everything, you'd expect -19Gt/yr; however, natural sinks like the ocean will start off-gassing, cutting the improvement to about half. Because of how long this switch will take, most IPCC options need 100 to 1000 Gt of net CO2 removal by the end of the century to limit the temperature increase to 1.5 degrees. | | |
| ▲ | margalabargala 2 days ago | parent [-] | | > The net CO2 impact of natural processes is -19Gt/yr. Humans add +37G/yr for a net +18Gt. If we stopped everything, you'd expect -19Gt/yr That is the message I am.trying to convey. |
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| ▲ | palata 2 days ago | parent | prev [-] | | > So the neat thing is that this isn't at all true. Then goes ahead explaining something completely different. | | |
| ▲ | margalabargala 2 days ago | parent [-] | | You were talking about how it'll be impossible to remove excess CO2 from the atmosphere without burning unreasonable amounts of energy. I say that's not so. We need only to sufficiently reduce emissions. | | |
| ▲ | palata 2 days ago | parent [-] | | > We need only to sufficiently reduce emissions. Well I agree on that. And even if we cut them to zero, the temperatures will not go down. So the very best we can hope is to keep the temperatures at the current level, and that's assuming that we cut all our emissions. And the fact remains that we would need unreasonable amounts of energy to extract CO2 from the atmosphere (it was suggested with solar panels and stuff). I didn't know that if we completely cut emissions, then CO2 would go down (and temperature would not during our lifetime, but they would at least stop rising). But "humans extracting CO2 from the atmosphere to compensate for their emissions" is impossible for the reasons I mentioned. |
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| ▲ | patapong 2 days ago | parent | prev [-] | | Very napkin math shows that annual energy consumption from fossil fuels is 500 exajoules. Every day the earth receives 15,000 exajoules in solar energy. So to cover double the energy consumption of fossil fuels with solar we need to cover 0.2% of the surface in solar. Compare to around 10% covered in farmland. Again, very back of the envelope math, but in my opinion this does not seem impossible. | | |
| ▲ | palata 2 days ago | parent [-] | | This is like saying "of course we can travel at the speed of light. Proof: the light does it, it's possible". |
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| ▲ | Henchman21 2 days ago | parent | prev [-] | | What are we going to replace concrete with? |
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| ▲ | xyzsparetimexyz 2 days ago | parent | prev | next [-] | | It is possible to get rid of excess CO2. Yes it goes against entropy, isn't very efficient and requires a ton of energy but we do have sources of tbe energy required in the form of the sun, nuclear, geothermal etc. But that doesn't matter while we're still emitting. | | | |
| ▲ | mayama 2 days ago | parent | prev | next [-] | | > 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. You can use pyrolysis to reduce usage of energy. Instead of building ethanol using corn etc, some fast growing crop can be converted to biochar using pyrolysis. And stored indefinitely underground or somewhere. Of course this isn't profitable and probably will run in to climate activists roadblocks. | |
| ▲ | BurningFrog a day ago | parent | prev [-] | | Maybe it's not clear that I'm talking about what to do with the excess CO₂ after we've stopped emitting more! The stratospheric injections of SO₂ can bring temperatures down to healthy levels. This fixes most of the negative effects of high CO₂, and can go on for centuries if need be... ... but I'd prefer to get that CO₂ out once and for all. Solar powered machines that extracts it from the air and pumps it down to eternal underground cavities should be able to do that once we have much better tech. If it takes decades or centuries doesn't matter too much. |
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| ▲ | ndsipa_pomu 3 days ago | parent | prev | next [-] |
| 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. |
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| ▲ | BurningFrog 2 days ago | parent [-] | | 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/ 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 2 days ago | parent | next [-] | | > 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 2 days ago | parent | next [-] | | > 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. | |
| ▲ | 2 days ago | parent | prev [-] | | [deleted] |
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| ▲ | ndsipa_pomu 2 days ago | parent | prev [-] | | 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. | | |
| ▲ | BurningFrog a day ago | parent [-] | | The SO₂ cleans up itself in ~2 years. | | |
| ▲ | ndsipa_pomu 19 hours ago | parent [-] | | I'm not sure what you mean by "cleans up itself" as it doesn't just disappear. What is likely is that it gets distributed through various ecosystems and thus is no longer in the stratosphere. What concerns me is our lack of knowledge about that process and secondary effects on ecosystems. Humanity has a track record of making assumptions about complex systems and treating them like a simple engine. | | |
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| ▲ | nozzlegear 2 days ago | parent | prev | next [-] |
| > 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-sho... |
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| ▲ | tda 2 days ago | parent | prev | next [-] |
| 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... |
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| ▲ | palata 2 days ago | parent | next [-] | | 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 2 days ago | parent | prev [-] | | You are talking about trees... | | |
| ▲ | obruchez 2 days ago | parent [-] | | Trees that disappear in huge fires more and more often, unfortunately. |
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| ▲ | teravor 2 days ago | parent | prev | next [-] |
| > Spray the stratosphere with SO₂
it will probably be more effective to introduce additives to jet fuel that form aerosols. something like sodium. |
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| ▲ | kybernetikos 2 days ago | parent | prev | next [-] |
| > 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. |
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| ▲ | potsandpans 2 days ago | parent | prev | next [-] |
| > 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/S00163... - https://www.frontiersin.org/journals/climate/articles/10.338... - https://agupubs.onlinelibrary.wiley.com/doi/10.1002/2017EF00... Further from an actual credible source: 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. |
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| ▲ | michaelbarton 3 days ago | parent | prev | next [-] |
| 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 |
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| ▲ | 0x_rs 3 days ago | parent [-] | | 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) |
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| ▲ | 2 days ago | parent | prev [-] |
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