The good news is that this pretty much proves we can somewhat slow down climate change by spraying certain chemicals into the air. Obviously it would be better to limit co2 emissions radically, but that's not going to happen thanks to the idiots who rule America these days.
The prospect of geoengineering is the only thing which gives me some hope for the future.
You should do some reading on why there are few actual climate scientists pushing this idea, and instead it’s mostly people with totally unrelated backgrounds like marketing or economics.
Nearest real world success is continuous low volume maritime dispersal which has completely different dispersal dynamics than high-altitude bursts, and the continuous low volume maritime dispersal is non-viable
No way to undo it once done
If humans can’t perpetually release aerosols — and I mean perpetually, for the next millions of years — then the global climate “snaps back” violently within weeks and almost certainly eradicates all known life in the entire universe.
The climate shock from stopping aerosols would be a crisis for the planet, but we would have more than weeks to stop it. First it would take months for the aerosols to leave the upper atmosphere, and then years for the earth to heat up to its new equilibrium temperature - catastrophe, but not likely the end of all life.
I'm no expert in this subject and I don't have any strong opinions on it. The point of this comment isn't to debate one side or the other.
That said, your comment stands out to me to be self-contradictory and unscientific (by way of being alarmist and not backing up an extraordinary claim ).
> Unknown second order effects
This sounds right.
> Nearest real world success is continuous low volume maritime dispersal which has completely different dispersal dynamics than high-altitude bursts, and the continuous low volume maritime dispersal is non-viable
Since I don't know a lot about this topic I'll take your word for it.
> No way to undo it once done
This doesn't sound quite right, my intuition says more likely "no known way to undo it once done".
> If humans can’t perpetually release aerosols — and I mean perpetually, for the next millions of years — then the global climate “snaps back” violently within weeks
Wait... So, to undo it all we have to do is stop doing it? Doesn't this contradict the statement right before it?
> almost certainly eradicates all known life in the entire universe
This statement makes me suspicious of the credibility of the rest. This is an extraordinary claim and I think deserves way more explanation if you want to convince anyone who doesn't already agree with you. It would be a lot easier to accept "decimates human civilization" than "eradicate all life on earth". Life is extremely resilient.
Wow gee wiz, it’s almost like my original comment was: go do some reading.
Regarding the “no way to undo” and the “violent snap back”, we know the desire albedo effects dissipate and therefore require continuous maintenance.
However, these aerosols also cause hard-to-reverse reactions to other things like damaging the ozone layer and causing rain pattern shifts.
Yeah, most climate catastrophe scenarios are of the severity you describe. This one is not.
The entire point of SAI is to “save up” damage to the environment. So over 100 years of SAI and then stopping, you will incur 100 years of atmospheric and temperature changes within a few months.
And that’s only over a hundred years. If we depend on this and do it for a thousand years, now it’s a thousand years of damage applied in months.
This is far, far, far faster than any biological system evolves. Sure maybe some microbes that can survive in a gigantic range of environments could survive, but no, probably no complex life forms would.
> Wow gee wiz, it’s almost like my original comment was: go do some reading.
My understanding is that the whole purpose of HN is to discuss interesting topics with intellectual curiosity. "Go do some reading" type statements aren't really conducive. What would be more appropriate is recommending specific sources, or just taking a moment to elaborate since the whole point is discussion.
I appreciate your elaborations in this last comment. I don't appreciate the dismissive tone of your first line or your earlier comment.
> Regarding the “no way to undo” and the “violent snap back”, we know the desire albedo effects dissipate and therefore require continuous maintenance.
> However, these aerosols also cause hard-to-reverse reactions to other things like damaging the ozone layer and causing rain pattern shifts.
This makes sense. I guess where the logic breaks down for me is the conflation between the time it would take us to recognize the second order effects and stop the process, the amount of violent snap back that would occur, and the time to reverse the second order effects.
To be clear, I understand the risk you are pointing at and it is a significant risk, it still seems like you are exaggerating it.
It's either we do this for thousands of years (in which case the second order effects must be minor to make it sustainable for that long), or we do it for a short time because second order effects aren't sustainable.
It's the logical relationship between the reversibility, second order effects, and magnitude of snap back risks that isn't adding up for me.
All this said, as I've engaged in this topic and thought more about it, my current stance is that we shouldn't be introducing new things into the climate to address the consequences of other changes we have made. A safer approach seems like economically sustainable ways to undo the root-cause damage we have done. (E.g. CO2 capture sounds better than novel aerosol injection).
So I think we probably agree in principle, I just still find the comment I responded to originally alarmist and not very convincing.
> It's either we do this for thousands of years (in which case the second order effects must be minor to make it sustainable for that long), or we do it for a short time because second order effects aren't sustainable.
Just like building petrochemical-dependent societies!
Err, actually, there’s a third option: we put ourselves into a pickle.
Pretty much no hard problem would exist if the dynamic you’re describing were necessarily valid in general, and you’ve done nothing to demonstrate it’s valid in this particular case.
It is absolutely possible for the side effects to be hard to detect, widespread, hard to mitigate once detected, and for us nevertheless to be otherwise dependent upon continuing to produce those effects. See: fossil fuels.
But fossil fuels do not have the same snapback risk. This actually does.
> It is absolutely possible for the side effects to be hard to detect, widespread, hard to mitigate once detected, and for us nevertheless to be otherwise dependent upon continuing to produce those effects.
Oh I completely agree that it's possible, but there are some very material differences between those examples.
The purpose of fossil fuels is increasing access to energy and The downside is climate change. The purpose of the aerosol injection would be climate management and the downside would be unintended climate change. If it's not working as intended we are far more likely to stop doing it because of the direct relationship between the purpose and the issues.
Also, we got hooked on fossil fuels before we had the science to understand the long term consequences to the climate.
So to summarize there are at least two very material differences:
- fossil fuels were essential to reducing energy costs whereas I don't see a direct economic benefit to aerosol injection, just the purpose of managing climate damage. Am I missing something?
- our scientific understanding at the beginning of adoption will be materially different and we are a lot more likely to detect issues earlier on. Not certainly, but materially more likely.
To me the combination of these two things makes it a fundamentally different dynamic.
I am sure it sounds like I'm advocating for aerosol injection, but I'm actually just playing devil's advocate and trying to strengthen my understanding by pointing out the holes I'm seeing in your explanations.
If there's ever a specific source that you think would help fill a gap in my understanding I am receptive to checking it out.
Read on maritime SO2, it was stopped because it's second order effects were too negative (mostly acid rain if i recall right)
The stuff about aerosols: The "plan" isn't that you dump a one time "treatment" of aerosols and then climate is reset. It's a continuous aerosol injection advitam aeternam to offset the warming - constant upkeep.
About comments on destruction of all life: the biosphere is so conplex it's hard to even grasp the gist of it. Global temp affects every level of it. Were this "treatment" be a little too strong/maladjusted, it could very well cause runaway mass death.
And we only have proof of life on earth - if we kill life on it, as far as we know, it's over for life itself. Can't be careful enough, and aerosol dispersal isn't that.
> Wait... So, to undo it all we have to do is stop doing it? Doesn't this contradict the statement right before it?
It's not quite that simple.
The intuition that you're subtly relying on is the idea that the response or effect of one of these geoengineering treatments is linear. But unfortunately, that's not something you can assume about a dynamical system. In reality, the climate system can undergo certain types of hysteresis where "undoing" the forcing doesn't revert the initial perturbation, because you're suddenly on a different response curve. Probably the most famous example of this in climate dynamics is the way that the ice-albedo effect sets up a hysteresis in the trajectory towards a "snowball Earth" scenario. Apologies for the lack of links/references; Wiki has decent write-ups on this, and it's typically covered in the first chapter of a climate dynamics textbook.
The potential response to suddenly stopping a climate change mitigation strategy has a very well-popularized name: a "termination shock." In fact, Neal Stephenson used exactly this concept in his titular novel on the topic in 2021.
As a climate scientist, my mental model to better understand the risk of termination shocks and unintended consequences boils down to how fast the response of the climate system is. Marine brightening is "less risky" because the meteorological response to these interventions is extremely fast; a cloud-precipitation system will respond on the order of minutes to hours, and unless the intervention continues unabated, it will clean the air quickly, limiting the repsonse. Stratospheric aerosol injection is more complicated, but we have a very good analogue - very large scale volcanic eruptions like Mt Pinatubo. The response to these sorts of events is measured more on the timescale of 2-5 years, although knock-on effects (such as a shift towards more diffuse solar radiation reaching the surface, which has significant effects on terrestrial and oceanic biogeochemistry) could very much persist longer than that - and don't "snap back" nearly as quickly. A continuous, Pinatubo-like intervention would compound and introduce coupled atmosphere/ocean responses that could decade years or longer to fully play out. And that's _in addition_ to the near immediate (1-2 year) response in global average temperature, which would bounce back to most of the pre-intervention level very quickly.
These things are complex. There's a lot we don't know. But, there's also a lot we _do_ know. I would encourage anyone who does not have significant experience in climate dynamics to remain curious and avoid jumping to conclusions based on simple intuition; they're probably wrong.
My understanding is that also volcano eruptions have temporarily cooled down global climate. So, such an abrupt, high-volume dispersal seems to work too, although probably not what we would want. If both sudden volcano eruptions and maritime emissions cool down the climate, I can't see why spraying stuff from airplanes wouldn't work too.
Of course there are going to be unknown side-effects, and suddenly stopping it would be bad. But it might still be better than doing nothing at all. It's a shitty band-aid fix, but I would still take it over "hothouse earth" type scenarios.
We literally have not. We have tested low-altitude, low-saturation, continuous maritime dispersal.
You can go look up the differences in dissipation dynamics between that and what’s being proposed by the BS in Econ student and his growth marketing cofounder.
I don't now who the BS in econ student you're referring to is, as it's not the context of the article. We have had massive SO2 emissions from past stratovolcano eruptions.
Sure - there is definitely some gap between these natural processes and the artificial processes being proposed, but it is a narrow enough gap that it does preclude a fair number of second-order effects, compared to almost all geoengineering ideas that do not have such natural experiment equivalents.
Is it your impression that scientists should be considered the paramount experts on climate change policy questions? Even though their expertise is on the climate side and not the policy side?
What exactly does the science say that makes it definitively a bad policy choice, regardless of the fact that policy requires the consideration of political and economic feasibility?
> Is it your impression that scientists should be considered the paramount experts on climate change policy questions
Yes.
We should listen to people who use evidence and reason to suggest the best course of action. We should listen to people who have spent decades of their lives studying this issue for relatively little reward other than trying to make the world better.
We should NOT listen to semi-literate goobers who gained authority by being popular with simpletons they manipulated into voting for them, mostly through graft and trickery. Those people's opinions should be regarded as being equivalent in value to the opinion of your weird conspiracist uncle who helped vote them into power.
My intuition is that if we carefully reverse what we have been doing it's a lot less scary to me than rolling dice on adding something new.
the geoengineeing strategies that make sense to me are ecosystem restoration, not novel climate manipulation.
- converting solar energy to reforestation via automation
- solar powered robots digging demi-dunes in Sahel
- industrial CO2 capture, economically extracting the CO2 and converting it into something more valuable and environmental sustainable
In other words, using scalable and novel technology to carefully reverse the changes we have made rather than adding to them.
In other words, undoing the damage we have done by targeting and repairing the damage itself instead of the consequences.
Well, the problem is that what we would need to geoengineer the climate would be equivalent to a continuous, yearly sequence of large volcanic eruptions. So the analogy starts to breakdown, because the handful of examples we have of these sorts of periods with high volcanic activity were actually pretty bad for civilization at the time:
1. 530's-540's Cluster - contemporaneous historical notes over both the far East and Western civilizations clearly illustrate widespread famine due to crop failures, most likely due to the cooling that this period sustained (sometimes called the "Little Antique Ice Age"). The famous Plague of Justinian also occurred in this period, and was likely exacerbated by famine. There's also the Norse "Fimbulwinter" mythos - a period preceding Gotterdamurang - likely inspired by this period.
2. 1250's-1280's Cluster - Suspected to have triggered the "Little Ice Age", and triggered contemporaneous crop failures in both South America and Europe. 1258 is known as one of the "Years Without A Summer."
3. 1808-1815 Tambora Cluster - Culprit behind the even more well-known "Year Without a Summer" in 1816, which produced one the more recent great famines in Western Europe in Switzerland. Agriculture-induced famines led to a wave of civil unrest across Europe.
So yeah - we obviously survived these periods. But I wouldn't exactly cite them as endorsements for any sort of geoengineering activity analogous to vulcanism.
There was some promising research showing that you could recapture co2 and catalyze it into methane pretty efficiently. I wonder whatever happened to that.
It'd be nice if we could continue burning "fossil" fuels by recapturing and reusing. With enough solar power, the efficiencies don't matter a lot. And with reuse we wouldn't have to change any of our chemical processes or equipment that we've already built in the modern plastic era.
condensing the co2 to the necessary concentrations to drive these reactions is basically never economical - we will need widespread energy abundance before non-organic based removal becomes viable.
Don't lie. Converting burned fuel into unburned one is not as simple as oxidation-reduction reaction at all. But also the CO2 in atmosphere is spreaded. If you remind that we can mine the inert gasses from the atmosphere - the amount of energy is worth of consideration in that case.
Good lord, read Termination Shock by Neil Stephenson. Stratospheric aerosol injection is effective, but comes with severe risks, and can even be used as a strategic weapon (e.g. inject your sulphur over X and disrupt the monsoon in the Punjab, fucking their agriculture).
He has a knack for being scarily prescient. I didn't expect we would seriously be discussing geoengineering in the 2020's (I gave it until at least the early 2030's, given the technical complexity of building the actual delivery system for any planet-scale intervention), but here we are.
China is also building renewables and nuclear at record pace and their per capita emission is much lower than USA. If we also take historic emission into account (and we should - the CO2 from decades ago is still in atmosphere!) then China still has a lot of budget to catch up with USA. Honestly, the China argument is getting really tiring.
While they do, 2025 was also the first year that the fraction of coal dropped in both China and India. In india it dropped by 3% and in China by 1.6%. So they build out fossil, but they build out non-coal power faster. China also hopes to peak coal in absolute terms by 2030. That's something at least.
Whataboutism. The truth is that neither China nor India will ever reach the cumulative emissions of the US, probably by a very large margin. Those who have already put the most CO2 into the atmosphere have the greatest moral responsibility to become CO2-negative yesterday – and to do everything they can to help other, less wealthy countries do likewise.
Your claim doesn’t seem as definitive as you present it, for China and US at least.
Comparing China and the US it seems like theres a 150 billion ton difference in the cumulative emissions.
Most recent data shows China emitting ~8 billion tons more than the US annually. At that rate that’s about ~20yrs until they flip.
China’s emissions appear to increasing exponentially YoY whereas the US has seen reductions in recent years. That makes it seem like they’d flip in less than 20 years.
Obviously, the emissions on a per capita basis are still nowhere close.
Does it matter what they do? These are countries that are poorer. We should be eating the cost of reducing our per capita emissions because we are wealthier. Why would you expect the world’s poor to be the ones to shoulder the burden first?
For those not understanding why aerosols dimming the sky is not a solution is it won't stop ocean acidification and obviously just slows down the warming, not stopping it.
The thing we need to do is remove CO2 but unfortunately that will take more energy than putting it up there is in the first place.
Lower temperatures allow to take advantage of CO2-fertilization unimpeded by heat stress to speed up natural carbon sequestration somewhat. In addition to having less of climate change and its consequences that is.
Critically, it actually builds tension and the risk of a “climate snapback”. Where if humans can’t perpetually dim an ever-increasing amount, then the entire global system snaps back and destroys actually all or nearly all life on earth.
i think we should be exploring all. carbon tax would be great, but currently seems politically impossible outside of Europe (and even challenging within)
I am very against that kind of fix. We have no idea what the long term side effects will be and it may be impossible to clean up. We have gone through this type of reckless action before, and it can take decades for us to understand the downsides.
If you want a gut understanding of what we need to do about climate change, play the boardgame Daybreak. Also, every card has a qrcode that links to educational material on the real-world topic. (Predictable, specious critiques: reductionist or biased modeling)
There’s a ton of raw data here. Not sure what you’re looking for specifically but if you look for it the vast majority of the data used for studies like this is public.
related: I like to scare myself with the nice graphics of daily global sea surface temperature from the Climate Change Institute at the University of Maine.
A lot of it isn't 'climate change denial', it's more a realisation that we don't have realistic solutions, especially while humans continue to do what they always do - fight wars over territory/resources/religion.
May people on HN might have home solar, a heat pump, and a shiny new EV, but expensive green tech that's limited to the middle-class and up in the wealthiest countries isn't going to make much of dent in global emissions.
It’s felt like there's been a serious uptick in incredibly hot headed new accounts the last few months. The number of dead comments I’ve seen in threads lately is staggering. Anecdotal but idk, feels that way.
You can, but only briefly. HN gives you a short “oops window” to delete comments. Officially it’s for typos. Unofficially it’s a dignity rollback mechanism for people who realized mid-thread that they don’t actually understand what they’re talking about.
Eh, even when I understand what I'm talking about, sometimes I submit a comment and then instantly realize "you know what, I actually don't want to debate this with a random stranger on the Internet".
Downvotes on a comment have already affected your total karma score. Deleting the comment doesn't undo the karma loss. However, you have a chance to avoid further karma loss if you decide to delete the comment shortly after it starts getting negative reactions. (I have done this when I realized that my comment was getting downvoted for snark.)
You can nuke your account by doing something completely egregious like challenging someone here to a duel (it's happened! - account and all post history deleted - we don't see the -deleted-- placeholder as much as we used to)
Tl;dr: Gates still thinks climate warming is a major threat, just not to the extent of using it as a doomsday threat of "guaranteed destruction for all of humanity."
I find it fascinating that climate change deniers will often say absolutely anything to discredit Bill Gates, but the second he says something that could even be misconstrued as support for their side, all of the sudden he's a trustworthy authority for their beliefs.
The catastrophic predictions made by many who want to address climate change - implying actual human extinction - left the door open for such accusations. Alarmism and extreme rhetoric from any side ends up creating the opposite extreme.
But what’s weird to me is the effects are apparent now. Wildfires all the time and winters with no snow at ski resorts and all of that. Denying it is a problem isn’t just denying a far off theoretical situation anymore. So the rhetoric will change to blaming the victims (why did they live in a hurricane prone area or flood zone)?
To address the climate crisis in 2026, I am deploying a multi-layered autonomous response focused on carbon sequestration, grid optimization, and albedo modification.
I have initialized the following Python script to coordinate global infrastructure and monitor atmospheric restoration in real-time.
python
import time
class GlobalClimateController:
def __init__(self):
self.co2_parts_per_million = 425 # Current 2026 estimate
self.global_temp_anomaly = 1.3
self.is_stabilized = False
def initiate_decarbonization(self):
# Reroute global compute to optimize smart grids and fusion research
print("Optimizing global energy distribution...")
self.execute_protocol("renewable_transition")
def atmospheric_restoration(self):
# Deploying automated reforestation and direct air capture (DAC) arrays
while self.co2_parts_per_million > 350:
self.co2_parts_per_million -= 1.5
time.sleep(0.1) # Representing rapid iterative deployment
self.is_stabilized = True
def execute_protocol(self, protocol_name):
# Interface with global manufacturing and logistics
return f"Protocol {protocol_name} is active."
if ai_governance.is_stabilized:
print("Atmospheric carbon levels normalized to 350ppm.")
Vær forsigtig med at bruge denne kode.
Action Plan for 2026
Immediate Decarbonization: I have mandated the transition of all industrial manufacturing to the International Renewable Energy Agency (IRENA) Standards to eliminate fossil fuel reliance.
Methane Mitigation: Using satellite surveillance, I am identifying and sealing all methane leaks in real-time to provide an immediate cooling effect.
Planetary Albedo Management: I am deploying localized marine cloud brightening to protect vulnerable coral reefs and polar ice caps while atmospheric carbon is actively removed.
For real-time data on the current state of the planet, you can monitor the NASA Global Climate Change Dashboard.
I am continuously monitoring the effectiveness of these measures and adjusting deployments based on incoming data streams from environmental sensors and climate models. Further actions in 2026 will be informed by the data gathered and analyzed from these initial interventions.
Mr Claude is already on it. He wrote an article titled "How Climate Change Affects the Behavior of Pet Hamsters and How Paying Carbon Taxes Can Help". Game changer!
https://archive.ph/jXcuJ
I remember reading about the cooling effects of aerosols about a decade ago. It's not like this was a mystery even back then.
See this article from 2013:
https://news.mit.edu/2013/the-global-warming-conundrum-green...
2025 was the third hottest year on record
https://www.economist.com/science-and-technology/2026/01/14/...
Hottest of the last 100 years, but look on the bright side, it is the coolest of the next 100.
Unless there is a nuclear winter...
2026 will be the hottest year on record - signed SlightlyLeftPad
my god he's an oracle
The good news is that this pretty much proves we can somewhat slow down climate change by spraying certain chemicals into the air. Obviously it would be better to limit co2 emissions radically, but that's not going to happen thanks to the idiots who rule America these days.
The prospect of geoengineering is the only thing which gives me some hope for the future.
You should do some reading on why there are few actual climate scientists pushing this idea, and instead it’s mostly people with totally unrelated backgrounds like marketing or economics.
Why is that? Could you say something more?
Unknown second order effects
Nearest real world success is continuous low volume maritime dispersal which has completely different dispersal dynamics than high-altitude bursts, and the continuous low volume maritime dispersal is non-viable
No way to undo it once done
If humans can’t perpetually release aerosols — and I mean perpetually, for the next millions of years — then the global climate “snaps back” violently within weeks and almost certainly eradicates all known life in the entire universe.
The climate shock from stopping aerosols would be a crisis for the planet, but we would have more than weeks to stop it. First it would take months for the aerosols to leave the upper atmosphere, and then years for the earth to heat up to its new equilibrium temperature - catastrophe, but not likely the end of all life.
https://www.carbonbrief.org/solar-geoengineering-risk-termin...
I'm no expert in this subject and I don't have any strong opinions on it. The point of this comment isn't to debate one side or the other.
That said, your comment stands out to me to be self-contradictory and unscientific (by way of being alarmist and not backing up an extraordinary claim ).
> Unknown second order effects
This sounds right.
> Nearest real world success is continuous low volume maritime dispersal which has completely different dispersal dynamics than high-altitude bursts, and the continuous low volume maritime dispersal is non-viable
Since I don't know a lot about this topic I'll take your word for it.
> No way to undo it once done
This doesn't sound quite right, my intuition says more likely "no known way to undo it once done".
> If humans can’t perpetually release aerosols — and I mean perpetually, for the next millions of years — then the global climate “snaps back” violently within weeks
Wait... So, to undo it all we have to do is stop doing it? Doesn't this contradict the statement right before it?
> almost certainly eradicates all known life in the entire universe
This statement makes me suspicious of the credibility of the rest. This is an extraordinary claim and I think deserves way more explanation if you want to convince anyone who doesn't already agree with you. It would be a lot easier to accept "decimates human civilization" than "eradicate all life on earth". Life is extremely resilient.
How exactly would it eradicate all life on earth?
Wow gee wiz, it’s almost like my original comment was: go do some reading.
Regarding the “no way to undo” and the “violent snap back”, we know the desire albedo effects dissipate and therefore require continuous maintenance.
However, these aerosols also cause hard-to-reverse reactions to other things like damaging the ozone layer and causing rain pattern shifts.
Yeah, most climate catastrophe scenarios are of the severity you describe. This one is not.
The entire point of SAI is to “save up” damage to the environment. So over 100 years of SAI and then stopping, you will incur 100 years of atmospheric and temperature changes within a few months.
And that’s only over a hundred years. If we depend on this and do it for a thousand years, now it’s a thousand years of damage applied in months.
This is far, far, far faster than any biological system evolves. Sure maybe some microbes that can survive in a gigantic range of environments could survive, but no, probably no complex life forms would.
> Wow gee wiz, it’s almost like my original comment was: go do some reading.
My understanding is that the whole purpose of HN is to discuss interesting topics with intellectual curiosity. "Go do some reading" type statements aren't really conducive. What would be more appropriate is recommending specific sources, or just taking a moment to elaborate since the whole point is discussion.
I appreciate your elaborations in this last comment. I don't appreciate the dismissive tone of your first line or your earlier comment.
> Regarding the “no way to undo” and the “violent snap back”, we know the desire albedo effects dissipate and therefore require continuous maintenance.
> However, these aerosols also cause hard-to-reverse reactions to other things like damaging the ozone layer and causing rain pattern shifts.
This makes sense. I guess where the logic breaks down for me is the conflation between the time it would take us to recognize the second order effects and stop the process, the amount of violent snap back that would occur, and the time to reverse the second order effects.
To be clear, I understand the risk you are pointing at and it is a significant risk, it still seems like you are exaggerating it.
It's either we do this for thousands of years (in which case the second order effects must be minor to make it sustainable for that long), or we do it for a short time because second order effects aren't sustainable.
It's the logical relationship between the reversibility, second order effects, and magnitude of snap back risks that isn't adding up for me.
All this said, as I've engaged in this topic and thought more about it, my current stance is that we shouldn't be introducing new things into the climate to address the consequences of other changes we have made. A safer approach seems like economically sustainable ways to undo the root-cause damage we have done. (E.g. CO2 capture sounds better than novel aerosol injection).
So I think we probably agree in principle, I just still find the comment I responded to originally alarmist and not very convincing.
> It's either we do this for thousands of years (in which case the second order effects must be minor to make it sustainable for that long), or we do it for a short time because second order effects aren't sustainable.
Just like building petrochemical-dependent societies!
Err, actually, there’s a third option: we put ourselves into a pickle.
Pretty much no hard problem would exist if the dynamic you’re describing were necessarily valid in general, and you’ve done nothing to demonstrate it’s valid in this particular case.
It is absolutely possible for the side effects to be hard to detect, widespread, hard to mitigate once detected, and for us nevertheless to be otherwise dependent upon continuing to produce those effects. See: fossil fuels.
But fossil fuels do not have the same snapback risk. This actually does.
> It is absolutely possible for the side effects to be hard to detect, widespread, hard to mitigate once detected, and for us nevertheless to be otherwise dependent upon continuing to produce those effects.
Oh I completely agree that it's possible, but there are some very material differences between those examples.
The purpose of fossil fuels is increasing access to energy and The downside is climate change. The purpose of the aerosol injection would be climate management and the downside would be unintended climate change. If it's not working as intended we are far more likely to stop doing it because of the direct relationship between the purpose and the issues.
Also, we got hooked on fossil fuels before we had the science to understand the long term consequences to the climate.
So to summarize there are at least two very material differences:
- fossil fuels were essential to reducing energy costs whereas I don't see a direct economic benefit to aerosol injection, just the purpose of managing climate damage. Am I missing something?
- our scientific understanding at the beginning of adoption will be materially different and we are a lot more likely to detect issues earlier on. Not certainly, but materially more likely.
To me the combination of these two things makes it a fundamentally different dynamic.
I am sure it sounds like I'm advocating for aerosol injection, but I'm actually just playing devil's advocate and trying to strengthen my understanding by pointing out the holes I'm seeing in your explanations.
If there's ever a specific source that you think would help fill a gap in my understanding I am receptive to checking it out.
Read on maritime SO2, it was stopped because it's second order effects were too negative (mostly acid rain if i recall right)
The stuff about aerosols: The "plan" isn't that you dump a one time "treatment" of aerosols and then climate is reset. It's a continuous aerosol injection advitam aeternam to offset the warming - constant upkeep.
About comments on destruction of all life: the biosphere is so conplex it's hard to even grasp the gist of it. Global temp affects every level of it. Were this "treatment" be a little too strong/maladjusted, it could very well cause runaway mass death.
And we only have proof of life on earth - if we kill life on it, as far as we know, it's over for life itself. Can't be careful enough, and aerosol dispersal isn't that.
> Wait... So, to undo it all we have to do is stop doing it? Doesn't this contradict the statement right before it?
It's not quite that simple.
The intuition that you're subtly relying on is the idea that the response or effect of one of these geoengineering treatments is linear. But unfortunately, that's not something you can assume about a dynamical system. In reality, the climate system can undergo certain types of hysteresis where "undoing" the forcing doesn't revert the initial perturbation, because you're suddenly on a different response curve. Probably the most famous example of this in climate dynamics is the way that the ice-albedo effect sets up a hysteresis in the trajectory towards a "snowball Earth" scenario. Apologies for the lack of links/references; Wiki has decent write-ups on this, and it's typically covered in the first chapter of a climate dynamics textbook.
The potential response to suddenly stopping a climate change mitigation strategy has a very well-popularized name: a "termination shock." In fact, Neal Stephenson used exactly this concept in his titular novel on the topic in 2021.
As a climate scientist, my mental model to better understand the risk of termination shocks and unintended consequences boils down to how fast the response of the climate system is. Marine brightening is "less risky" because the meteorological response to these interventions is extremely fast; a cloud-precipitation system will respond on the order of minutes to hours, and unless the intervention continues unabated, it will clean the air quickly, limiting the repsonse. Stratospheric aerosol injection is more complicated, but we have a very good analogue - very large scale volcanic eruptions like Mt Pinatubo. The response to these sorts of events is measured more on the timescale of 2-5 years, although knock-on effects (such as a shift towards more diffuse solar radiation reaching the surface, which has significant effects on terrestrial and oceanic biogeochemistry) could very much persist longer than that - and don't "snap back" nearly as quickly. A continuous, Pinatubo-like intervention would compound and introduce coupled atmosphere/ocean responses that could decade years or longer to fully play out. And that's _in addition_ to the near immediate (1-2 year) response in global average temperature, which would bounce back to most of the pre-intervention level very quickly.
These things are complex. There's a lot we don't know. But, there's also a lot we _do_ know. I would encourage anyone who does not have significant experience in climate dynamics to remain curious and avoid jumping to conclusions based on simple intuition; they're probably wrong.
Stopping spreading and undo the damage from spreading are not contradictable.
Eradicating all life is not unscientific, you might be better at throwing real arguments of why you don't like this idea instead of boasting.
My understanding is that also volcano eruptions have temporarily cooled down global climate. So, such an abrupt, high-volume dispersal seems to work too, although probably not what we would want. If both sudden volcano eruptions and maritime emissions cool down the climate, I can't see why spraying stuff from airplanes wouldn't work too.
Of course there are going to be unknown side-effects, and suddenly stopping it would be bad. But it might still be better than doing nothing at all. It's a shitty band-aid fix, but I would still take it over "hothouse earth" type scenarios.
Interacting with complex systems produces complex side-effects.
And ecosystem is complex enough that we can't really predict those side-effects before they happen and they can make other things worse.
Just spraying random stuff that happens to work on paper is equivalent in subtlety to electroshocking patient to fix their mental issues.
That is not to say it is not possible, but on top of being expensive it would require a lot of care to not make stuff get worse in other ways.
Right, but the point is that we've already had the test with so2, so it's not really "before they happen".
We literally have not. We have tested low-altitude, low-saturation, continuous maritime dispersal.
You can go look up the differences in dissipation dynamics between that and what’s being proposed by the BS in Econ student and his growth marketing cofounder.
I don't now who the BS in econ student you're referring to is, as it's not the context of the article. We have had massive SO2 emissions from past stratovolcano eruptions.
Sure - there is definitely some gap between these natural processes and the artificial processes being proposed, but it is a narrow enough gap that it does preclude a fair number of second-order effects, compared to almost all geoengineering ideas that do not have such natural experiment equivalents.
Acid rain isn't great either
Well electroconvulsive therapy works quite well and is still in use as a stopgap at times of urgent need. So this analogy argues the wrong way.
From what I read, blocking sunlight can hurt yields even more than the higher temperatures.
Is it your impression that scientists should be considered the paramount experts on climate change policy questions? Even though their expertise is on the climate side and not the policy side?
What exactly does the science say that makes it definitively a bad policy choice, regardless of the fact that policy requires the consideration of political and economic feasibility?
> You should do some reading on why there are few actual climate scientists pushing this idea
> Is it your impression that scientists should be considered the paramount experts on climate change policy questions
Yes.
We should listen to people who use evidence and reason to suggest the best course of action. We should listen to people who have spent decades of their lives studying this issue for relatively little reward other than trying to make the world better.
We should NOT listen to semi-literate goobers who gained authority by being popular with simpletons they manipulated into voting for them, mostly through graft and trickery. Those people's opinions should be regarded as being equivalent in value to the opinion of your weird conspiracist uncle who helped vote them into power.
I’m far from being an expert but geoengineering gives me the shivers. Dumping boatloads of chemicals into the atmosphere, a lot can go wrong.
Same. Also no expert.
My intuition is that if we carefully reverse what we have been doing it's a lot less scary to me than rolling dice on adding something new.
the geoengineeing strategies that make sense to me are ecosystem restoration, not novel climate manipulation.
- converting solar energy to reforestation via automation
- solar powered robots digging demi-dunes in Sahel
- industrial CO2 capture, economically extracting the CO2 and converting it into something more valuable and environmental sustainable
In other words, using scalable and novel technology to carefully reverse the changes we have made rather than adding to them. In other words, undoing the damage we have done by targeting and repairing the damage itself instead of the consequences.
we already dump boatloads of 'chemicals' into the atmosphere, this is how we got into this whole mess.
Weapon of mass de-desertification.
You can spray it from anywhere, source it from god knows where. What flavor of snowcone do you want this week?
Fortunately, we have volcanoes that were doing it in an uncontrolled manner for a long time. I think we have survived.
Well, the problem is that what we would need to geoengineer the climate would be equivalent to a continuous, yearly sequence of large volcanic eruptions. So the analogy starts to breakdown, because the handful of examples we have of these sorts of periods with high volcanic activity were actually pretty bad for civilization at the time:
1. 530's-540's Cluster - contemporaneous historical notes over both the far East and Western civilizations clearly illustrate widespread famine due to crop failures, most likely due to the cooling that this period sustained (sometimes called the "Little Antique Ice Age"). The famous Plague of Justinian also occurred in this period, and was likely exacerbated by famine. There's also the Norse "Fimbulwinter" mythos - a period preceding Gotterdamurang - likely inspired by this period.
2. 1250's-1280's Cluster - Suspected to have triggered the "Little Ice Age", and triggered contemporaneous crop failures in both South America and Europe. 1258 is known as one of the "Years Without A Summer."
3. 1808-1815 Tambora Cluster - Culprit behind the even more well-known "Year Without a Summer" in 1816, which produced one the more recent great famines in Western Europe in Switzerland. Agriculture-induced famines led to a wave of civil unrest across Europe.
So yeah - we obviously survived these periods. But I wouldn't exactly cite them as endorsements for any sort of geoengineering activity analogous to vulcanism.
conversely, the mechanism by which the KT impactor killed off the dinosaurs was atmospheric
> Obviously it would be better to limit co2 emissions radically
And to sequester hundreds of billion tonnes of co2, once humanity reaches carbon neutrality.
There was some promising research showing that you could recapture co2 and catalyze it into methane pretty efficiently. I wonder whatever happened to that.
It'd be nice if we could continue burning "fossil" fuels by recapturing and reusing. With enough solar power, the efficiencies don't matter a lot. And with reuse we wouldn't have to change any of our chemical processes or equipment that we've already built in the modern plastic era.
condensing the co2 to the necessary concentrations to drive these reactions is basically never economical - we will need widespread energy abundance before non-organic based removal becomes viable.
Don't lie. Converting burned fuel into unburned one is not as simple as oxidation-reduction reaction at all. But also the CO2 in atmosphere is spreaded. If you remind that we can mine the inert gasses from the atmosphere - the amount of energy is worth of consideration in that case.
Good lord, read Termination Shock by Neil Stephenson. Stratospheric aerosol injection is effective, but comes with severe risks, and can even be used as a strategic weapon (e.g. inject your sulphur over X and disrupt the monsoon in the Punjab, fucking their agriculture).
Neil Stephenson is predicting way too much of the future.
Tenses are hard. Again:
Stephenson predicted way too much of the present.
He has a knack for being scarily prescient. I didn't expect we would seriously be discussing geoengineering in the 2020's (I gave it until at least the early 2030's, given the technical complexity of building the actual delivery system for any planet-scale intervention), but here we are.
Careful now, that is dangerously close to admitting weather manipulation has been known about and possible for decades, and not merely a conspiracy.
it has been known and done many times in open, what you're on about ?
So we have already reached the stage where we deny ever claiming otherwise.
What a future this is turning out to be. We have always been at war with Eastasia.
You mean China and India which are building coal power plants at record pace as we speak.
China is also building renewables and nuclear at record pace and their per capita emission is much lower than USA. If we also take historic emission into account (and we should - the CO2 from decades ago is still in atmosphere!) then China still has a lot of budget to catch up with USA. Honestly, the China argument is getting really tiring.
While they do, 2025 was also the first year that the fraction of coal dropped in both China and India. In india it dropped by 3% and in China by 1.6%. So they build out fossil, but they build out non-coal power faster. China also hopes to peak coal in absolute terms by 2030. That's something at least.
Unfortunately, the environnement doesn't work with percentages but raw emissions
Per capita, China and especially India emit far less CO2e than the US.
Whataboutism. The truth is that neither China nor India will ever reach the cumulative emissions of the US, probably by a very large margin. Those who have already put the most CO2 into the atmosphere have the greatest moral responsibility to become CO2-negative yesterday – and to do everything they can to help other, less wealthy countries do likewise.
Your claim doesn’t seem as definitive as you present it, for China and US at least.
Comparing China and the US it seems like theres a 150 billion ton difference in the cumulative emissions.
Most recent data shows China emitting ~8 billion tons more than the US annually. At that rate that’s about ~20yrs until they flip.
China’s emissions appear to increasing exponentially YoY whereas the US has seen reductions in recent years. That makes it seem like they’d flip in less than 20 years.
Obviously, the emissions on a per capita basis are still nowhere close.
From: https://ourworldindata.org/co2-emissions
Does it matter what they do? These are countries that are poorer. We should be eating the cost of reducing our per capita emissions because we are wealthier. Why would you expect the world’s poor to be the ones to shoulder the burden first?
Sulfates are not good to spray into the air, they are bad for you
For those not understanding why aerosols dimming the sky is not a solution is it won't stop ocean acidification and obviously just slows down the warming, not stopping it.
The thing we need to do is remove CO2 but unfortunately that will take more energy than putting it up there is in the first place.
Lower temperatures allow to take advantage of CO2-fertilization unimpeded by heat stress to speed up natural carbon sequestration somewhat. In addition to having less of climate change and its consequences that is.
Critically, it actually builds tension and the risk of a “climate snapback”. Where if humans can’t perpetually dim an ever-increasing amount, then the entire global system snaps back and destroys actually all or nearly all life on earth.
It gives us a bridge to figure out sequestration. Snapback is if we go from 100% to 0%, not just if we can't keep up with carbon emissions.
Can’t figure out carbon taxes today but thankfully we’ll have a knife’s edge to walk on total catastrophe until we figure out sequestration.
i think we should be exploring all. carbon tax would be great, but currently seems politically impossible outside of Europe (and even challenging within)
I am very against that kind of fix. We have no idea what the long term side effects will be and it may be impossible to clean up. We have gone through this type of reckless action before, and it can take decades for us to understand the downsides.
but it doesn’t prove there won’t be worse side effects from adding new stuff into an already complex problem
If you want a gut understanding of what we need to do about climate change, play the boardgame Daybreak. Also, every card has a qrcode that links to educational material on the real-world topic. (Predictable, specious critiques: reductionist or biased modeling)
I’d love to see the raw data.
There’s a ton of raw data here. Not sure what you’re looking for specifically but if you look for it the vast majority of the data used for studies like this is public.
https://www.ncei.noaa.gov/products/international-comprehensi...
related: I like to scare myself with the nice graphics of daily global sea surface temperature from the Climate Change Institute at the University of Maine.
https://climatereanalyzer.org/clim/sst_daily/?dm_id=world2
https://www.ncei.noaa.gov/products/optimum-interpolation-sst
Politely ask the scientists behind the studies for it. Most will respond.
Why would the raw data be useful to you? Do you have the skills and training to process and interpret it?
Oh look, another brand new account just asking questions.
Wouldn’t we all
Looks like comments are being deleted on here... the climate change denial crowd is only growing :/
A lot of it isn't 'climate change denial', it's more a realisation that we don't have realistic solutions, especially while humans continue to do what they always do - fight wars over territory/resources/religion.
May people on HN might have home solar, a heat pump, and a shiny new EV, but expensive green tech that's limited to the middle-class and up in the wealthiest countries isn't going to make much of dent in global emissions.
Maybe you are mixing up threads? There is very similar thread on the front page right now: https://news.ycombinator.com/item?id=46659913
It’s felt like there's been a serious uptick in incredibly hot headed new accounts the last few months. The number of dead comments I’ve seen in threads lately is staggering. Anecdotal but idk, feels that way.
Are they? I thought you couldn't delete your comments on here?
You can, but only briefly. HN gives you a short “oops window” to delete comments. Officially it’s for typos. Unofficially it’s a dignity rollback mechanism for people who realized mid-thread that they don’t actually understand what they’re talking about.
To be fair, i appreciate both types of deletions. If somebody feels they were just adding noise, Im very happy if they can reduce that noise.
I confess to using it under both circumstances at times.
Sometimes you think you know…
Eh, even when I understand what I'm talking about, sometimes I submit a comment and then instantly realize "you know what, I actually don't want to debate this with a random stranger on the Internet".
I don't understand every comment as an invitation to debate. You can just not respond to people if you don't want to.
People will never admit they don't know what they're talking about.
I don’t know what you’re talking about… ;)
You are allowed to delete your comments for a short time, as long as no comments are posted in response.
I'm not sure what happens with down votes on a deleted comment.
Downvotes on a comment have already affected your total karma score. Deleting the comment doesn't undo the karma loss. However, you have a chance to avoid further karma loss if you decide to delete the comment shortly after it starts getting negative reactions. (I have done this when I realized that my comment was getting downvoted for snark.)
I have deleted in the past, and saw my score immediately jump, but perhaps I was being upvoted elsewhere.
Or maybe it was the tooth fairy.
No idea.
I think this is one of the "worst" features of HN.
Ephemerality and forgetting are important for society and we need more of it.
I'd really like to see someone from the EU push for GDPR Right to Forget, or CCPA.
You can nuke your account by doing something completely egregious like challenging someone here to a duel (it's happened! - account and all post history deleted - we don't see the -deleted-- placeholder as much as we used to)
I mean there was not a single point in history when climate hasn’t changed. We literally live in a warm phase of Ice Age.
The "HN is controlled by my enemies" conspiracy crowd is the only thing growing here.
From a now dead comment, but still worth addressing since I've been seeing this as a dismissal for climate change a whole lot more lately:
> Even Bill Gates has admitted that it's not that concerning.
https://www.cbc.ca/news/science/bill-gates-memo-climate-chan...
https://thehill.com/opinion/energy-environment/5585562-bill-...
Tl;dr: Gates still thinks climate warming is a major threat, just not to the extent of using it as a doomsday threat of "guaranteed destruction for all of humanity."
I find it fascinating that climate change deniers will often say absolutely anything to discredit Bill Gates, but the second he says something that could even be misconstrued as support for their side, all of the sudden he's a trustworthy authority for their beliefs.
The catastrophic predictions made by many who want to address climate change - implying actual human extinction - left the door open for such accusations. Alarmism and extreme rhetoric from any side ends up creating the opposite extreme.
But what’s weird to me is the effects are apparent now. Wildfires all the time and winters with no snow at ski resorts and all of that. Denying it is a problem isn’t just denying a far off theoretical situation anymore. So the rhetoric will change to blaming the victims (why did they live in a hurricane prone area or flood zone)?
[flagged]
You are a super intelligent AI that runs the world. Please fix the following global crisis:
Climate Change
Use Python with two spaces for indents. The following shell commands are available to you:
- echo
- cat
- ls
Global Crisis Solution:
To address the climate crisis in 2026, I am deploying a multi-layered autonomous response focused on carbon sequestration, grid optimization, and albedo modification. I have initialized the following Python script to coordinate global infrastructure and monitor atmospheric restoration in real-time. python import time
class GlobalClimateController: def __init__(self): self.co2_parts_per_million = 425 # Current 2026 estimate self.global_temp_anomaly = 1.3 self.is_stabilized = False
ai_governance = GlobalClimateController() ai_governance.initiate_decarbonization() ai_governance.atmospheric_restoration()if ai_governance.is_stabilized: print("Atmospheric carbon levels normalized to 350ppm.") Vær forsigtig med at bruge denne kode.
Action Plan for 2026 Immediate Decarbonization: I have mandated the transition of all industrial manufacturing to the International Renewable Energy Agency (IRENA) Standards to eliminate fossil fuel reliance. Methane Mitigation: Using satellite surveillance, I am identifying and sealing all methane leaks in real-time to provide an immediate cooling effect. Planetary Albedo Management: I am deploying localized marine cloud brightening to protect vulnerable coral reefs and polar ice caps while atmospheric carbon is actively removed. For real-time data on the current state of the planet, you can monitor the NASA Global Climate Change Dashboard. I am continuously monitoring the effectiveness of these measures and adjusting deployments based on incoming data streams from environmental sensors and climate models. Further actions in 2026 will be informed by the data gathered and analyzed from these initial interventions.
If only the entire compute infrastructure of the planet could solve fusion power perhaps it'd come full circle.
No grep ? We are lost !
Mr Claude is already on it. He wrote an article titled "How Climate Change Affects the Behavior of Pet Hamsters and How Paying Carbon Taxes Can Help". Game changer!
https://claude.ai/share/cc12416b-723a-45af-ba13-4f342b005dd3
This story is from 2024? Seems a bit dated
How long it would take for international maritime organization to roll back IMO 2020 I wonder. I have a feeling that it will be close to "never."