The likelihood of unilateral solar geoengineering | Hacker News Reader

The likelihood of unilateral solar geoengineering

climate.benjames.io

110 pointsarthurdenture121 comments

"We don't know who struck first, us or them. But we know that it was us that scorched the sky. At the time, they were dependent on solar power and it was believed that they would be unable to survive without an energy source as abundant as the sun."

- Morpheus, The Matrix

But what we know for certain is that at some point in the early 21st century all of mankind was united in celebration. We marveled at our own magnificence as we gave birth to AI.

Plot Twist:

- AI is not smart enough to take over humanity.

- But by playing god with geoengineering by having rain packed with sulfur on our crops, we are facing The Blight, like in Interstellar.

You know what they say: Artificial intelligence is no match for natural stupidity...

The matrix was Fiction, Neo. This war on a warming planet, we're not winning it fast enough. I support the move.

I love everything about The Matrix, except that the core premise makes no sense. Humans are not an energy source; at best we (very inefficiently) transform energy from one form to another.

If we “scorched the sky,” humans would be at least as screwed as the robots, unless we’re getting all our energy (and tons more since we’d have to move all agriculture indoors) from nuclear or such, but in that case, what on earth would the robots need us for? Wouldn’t they just start running nuclear plants? Seems a lot simpler than running the matrix.

Feels like such a sloppy plot hole for an otherwise brilliantly entertaining film.

Originally humans were used as computers, not energy source, which made more sense. Some brilliant mind changed it at some point during production.

If they were used as super efficient neural nets that compute by dreaming, it would have been amazing

I'm continually surprised that this idea gets so much traction. While possible to build, it's also strictly Temporary and just leaves us with a worse problem later on. We'll just need a bigger one, 20 years down the line, when CO2 levels keep going up! At some point, it's pretty obviously a non-solution.

Let's put this energy into Nuclear Power and CO2 recapture; and actually fix things.

Nuclear power is not affordable, wind and solar are far more cost effective. Carbon capture is a great application for a variable supply grid as it can easily be load shed.

The affordability of nuclear power is purely political (and emotional).

In the real world nuclear costs in the $80 per MWh range, nearly twice that of offshore wind

The growth of renewables, particularly solar, is on pace to replace a pretty large proportion of fossil fuels "for free" by being more economically viable. Transitioning most people and industry from ICE to electric and things like heating to more electric is going to happen naturally, but it'll take a few decades. Likewise it's reasonable to believe the biosphere is going to ramp up carbon sinking as time goes by. A stopgap of dimming the sun with sulfur for... eh... 20 years might just be the ticket.

> is on pace to replace a pretty large proportion of fossil fuels

Is it? According to ourwoldindata[0], fossil fuel usage is growing worldwide. ie more fossil fuels are being burned now than ever before.

[0] https://ourworldindata.org/grapher/global-fossil-fuel-consum...

Yes. Solar is growing at an exponential rate, fossil fuel growth rates have been slowing.

Solar and wind growth rates should be expected to continue increasing, fossil fuel growth should reach zero in the next decade and start a long term decline.

https://en.m.wikipedia.org/wiki/Growth_of_photovoltaics

I’m talking about the second derivative of usage not the first.

> Spraying a form of sulfur from a plane is incredibly cheap. A full programme would cost less than $20b per year. That’s much cheaper than carbon removal ($600b per year, to remove just 10% of annual emissions @ $100 / tCO2).

It is 30x higher both in time and cost to capture carbon. At $20B/yr geoengineering the atmosphere can be done for 50+ yrs. In 50yrs, carbon capture would need $30T vs only $1T for spraying sulfur. Carbon capture as a long-term solution doesn't make sense. Also, how much carbon you can capture in 50yrs? At 10% of annual emissions, you can probably reach 30% by the end of 50yrs. Carbon capture is still leaving 70% carbon in the environment. It's a make believe solution build to give us false sense of action for saving climate.

Among other downsides, spraying sulphur in the atmosphere doesn't remove any Carbon at all. It just tries to balance one pollutant out with another. I'd rather have the sunshade, honestly.

I'm not a physical scientist, but I'd imagine that the amount of Carbon you can capture is fundamentally proportional to the energy you can use on Carbon Capture. That's why I believe a large expansion of Nuclear Energy would be needed.

Alongside a continued reduction in emissions, this is a practical path forward. Throwing new curveballs at the earth, while not addressing the present level of Carbon, is not.

That's not the point the author is trying to make. What he's saying is, whether you like it or not, it's cheap enough that somebody will do it, either a desperate government or an individual American technocrat.

If I did my back of the envelope math right, direct air capture (DAC) at the currently commercially feasible efficiency, powered by nuclear power could capture annually about as much CO2 as we emit annually if powered by around 2300 large nuclear plants.

It could also be done with roughly a million km^2 worth of solar panels.

I'm curious...do we have the resources to build either that many large nuclear power plants or that many solar panels?

What do sulfur damages to crops cost?

And can we breathe that? At some point it's gonna be noticeable, right?

sulfur is one of those things people can detect in ppm... so yeah maybe

we screwed up the earth so much the only way to keep it livable to is to make it smell like farts

In the United States I strongly suspect that at least one major political party's reaction to sulfur spraying would be to try to increase the production and use of coal and oil.

I suspect that this reaction would not be confined to the US.

We could end up in a situation where greenhouse gas levels in 50-100 years are massively higher than they are now, with heating being held in check by continual sulphur spraying.

It would then only take for something to disrupt the sulphur spraying for a year to have sudden massive warming.

It would make more sense to save sulphur spraying for after we are firmly on the road to zero emissions and have reached the point where it is not economically feasible to revive coal and oil. Then sulphur spraying as a temporary measure to lower temperature until our falling emissions make it unnecessary might be safe.

That won't be easy for them to justify when solar, wind and battery prices are cheaper.

You know that famous (around here) article: "Reality Has A Surprising Amount of Detail" ?

Sadly for all of its popularity the essential message seems to have missed people. I listen to people talk about Mars colonies in their lifetime, because they refuse to acknowledge the complexity beyond "big rocket go fast". This topic is very similar, it requires a staggering amount of engineering, economic, environmental and other disciplines to really understand why it's such a terrible idea. The expense, the known and unknown unknowns, the politics and the reality that it's a band-aid over a sucking chest wound.

People just don't get it, and only engage with these topics as a sort of sport, not something they need to grasp the complexity of.

The article makes the point that it's the kind of thing an arrogant billionaire will probably do on their own because they feel it's necessary. I'd say that your point probably reinforces that idea.

Excellent comment.

>While possible to build, it's also strictly Temporary and just leaves us with a worse problem later on.

Sounds like how humans have been operating since eons.

The history of industrialization, as well as most people’s consumer choices, should explain why it has so much traction. When faced with an expensive solution that permanently solves a problem vs a cheap one that kicks the can down the road a few years, people invariably choose the cheap one. That’s how we got in this mess in the first place.

Remember that people are mortal. Rather than invest in permanent solutions that grant us eternal life, evolution favors solutions that keep us alive just long enough to reproduce, then making a half-copy and throwing out the old body.

A nuclear power plant generating 5gwh/year could capture around 4 million tons of CO2 per year at 1,200 kwh per ton. Emissions are in the billions of tons per year.

I hear that argument lot, but the perspective that seems missing to me are the secondary effects - right now, we have a lot of self-reinforcing loops from rising temperatures, like melting permafrost emitting even more greenhouse gases. At least those should stop if the earth is artificially cooled down, no? If so, then it could be considered a form of preemptive removal - stop it from getting into the atmosphere in the first place. Not sufficient on its own, but a bandaid that would buy some time (which has its own risks, given our record of dealing with problems too late).

While possible to build, it's also strictly Temporary

And may, as per the author says, save our asses while we get our shit together.

Now, granted, this is one of the craziest things Ive ever read in my life. And Im being proportionate here.

It's just an insanely large and dangerous and global version of setting up a sprinkler or mister to use to cool off when it gets too hot outside.

The magnitudes of the vectors are much much larger, but it's the same dimensions of environmental modification for our own comfort.

What's funny is I think it's one of the most rational takes on the current situation that I've ever read. What's crazy is the status quo wherein we are destroying the only ecosystem that can support our civilization. We are already engineering the climate, just not purposefully.

We are already not doing much against climate change now, so "get our shit together" is wishful thinking.

This is just another distraction from the list:

- "there is no climate change, let's continue business as usual"

- "there is climate change, but not human-made, let's continue business as usual"

- "there is human-made climate change but it is too late, let's continue business as usual"

- "environmental activists are to blame, let's continue business as usual"

- "maybe we will find magic-technology, let's continue business as usual"

- "geoengineering will buy some time, let's continue business as usual"

I think there are certain actions that are only insufficient because the trend line isn't steep. Electric car sales go up every year, solar/wind both go up as a % of our energy mix in the west every year. Some amount of geoengineering might allow the current pace of those trends to be 'fast enough'

exactly. we need more time for the trends to mature.

I disagree; I think we are doing a lot. We're on track so that renewable sources will provide 1/3 of all electricity generation by 2025. That's quite a massive change, considering how much electricity infrastructure needs to change for that to happen.

The issue is that CO2 emission is so massive that even big changes are a drop in the bucket.

Dude you're discounting things like the fact that solar and wind account for like 44 percent of europe and even in the united states I go driving around and see solar panels everywhere. Like, it's all growing like a weed and going gang busters but still it needs to go even fater sure but buy us time and solar and wind would get even cheaper along with batteries and anyone who tried to advocate for more coal or natural gas would be met with resistance in corporate america as there are cheaper alternatives.

> just leaves us with a worse problem later on

That's the beautiful part. When wintertime rolls around, the gorillas simply freeze to death.

"If your solution closely follows the story line of the Simpsons, perhaps reconsider" – The Simpson Solution Axiom

"Since the beginning of time, Man has yearned to destroy the sun. I will do the next best thing: block it out!"

https://www.youtube.com/watch?v=L3LbxDZRgA4

I was reminded of Futurama actually :)

"Thus solving the problem once and for all." https://www.youtube.com/watch?v=VW66EX75jIY

This story about urban albedo interested me earlier [0].

Painting roofs and roads white, and simply having more green parks instead of paved areas would actually make a difference.

[0] https://news.ycombinator.com/context?id=39356361

Urban area is around half percent of earth area (2 mln km2 vs 510).

Improving albedo there may have some local effect, but unlikely to contribute significantly to climate change mitigation.

Solar irradiation is around 1000 W/m2, and greenhouse gas forcing is about 2.5 W/m2, so it's not that outlandish.

This title is breaking HN's guidelines by being linkbait. ("Please use the original title, unless it is misleading or linkbait" - https://news.ycombinator.com/newsguidelines.html)

Can anyone suggest a less baity title? I looked through the text trying to find an accurate, neutral, representative phrase and couldn't find one. That's unusual and probably a bad sign.

I don't think it is baity? Just creative and interesting. Meshes perfectly with its content too, as the main argument of the article is that someone is going to do it without any general consensus as it is possible to do with some billionaire or small nation level cash.

Maybe:

    Solar Radiation Management (SRM) as a temporary climate change solution

"On the likelihood of unilateral solar geoengineering"?

The article itself edges on mongering to be fair.

Ok, let's try that. Thanks to everyone for all the suggestions!

> Modifying the earth like this is called geoengineering, and blocking out the sun with particles is called Solar Radiation Management (SRM).

"Solar Radiation Management (SRM)" alone is probably succinct and neither misleading or linkbait.

That's unusual and probably a bad sign.

It's a bad, bad sign I agree. That said Id propose "someone may decide to pour sulphur in the stratosphere"

Still link bait-y and but infinitely better. You have my vote!

I think the last part of the conclusion is relatively representative:

> people are starting to take geoengineering seriously

It could be made more objective by prepending "Some" :) Though the author does give a bunch of references under #2 and #3 so perhaps it's unnecessary.

I thought of something like that too, but decided that it's not specific enough since the post is not about geoengineering in general.

Various small organisations are already doing a number of geoengineering projects on the ocean and various other biomes/habitats. Its simply a matter of time and there is currently no framework to stop it happening, anyone with the funding can just do this and break no laws. If it all goes wrong due to unforeseen consequences we all suffer. Just like climate change really, people on the other side of the planet are causing harm to everyone and refuse to stop.

This was the plot of Termination Shock by Neal Stephenson

Glad you brought this up. The CO2 doesn't go away with geoengineering. It's still being pumped into the atmosphere and will dramatically warm the planet in a much shorter time period if the geoengineering stops

I wonder if simply tainting the fuel of airliners with sulfur would be good enough for a meaningful effect.

A half a percent in the global jet fuel supply would put that order of sulfur into the atmosphere, a bit lower than what I think is being proposed here. But adulterating the fuel supply would be affordable and equivalent to a smallish tax on flight.

This is a really interesting idea to me, honestly. Someone would have to do some modeling, but I'm guessing that amount being emitted would be low enough to not dramatically cool the Northern Hemisphere (where most of the air traffic is) and messing up some weather patterns. The author stresses several times in TFA that sulfur emissions should be done at the equator to have an equal, global effect.

actual chemtrails, the conspiracy theorists will love it!

> and (more practically) high-altitude balloons filled with sulfur and hydrogen/helium.

Helium's a bad thing to fill with because it's a limited resource. Hydrogen is bad because it's a sink for greenhouse gas eliminating hydroxyl. https://e360.yale.edu/features/natural-geologic-hydrogen-cli...

: For instance, some of the hydrogen released will react with the atmospheric compound hydroxyl, creating ozone, which in the lower atmosphere is a greenhouse gas. And by using up hydroxyl, which is the atmosphere’s main cleansing agent, hydrogen will leave less of the organic compound available to break down methane and other greenhouse gases, resulting in those gases lasting longer in the atmosphere and causing additional warming.

The idea that a billionaire is just going to yeet a program together is pretty far fetched. Even at "only" $20 billion dollars a year, there are less than a dozen billionaires in the world with that kind of free capital. And none of them could sustain that kind of spend for more than 1-2 years.

The "country of no choice" similarly applies to only a small handful of countries that have no decent way of mitigating climate change but also have the funds and resources to do SRM. So really, just China (which has already shown enthusiasm towards geoengineering) or India.

The primary human response is still going to be crop adaptation and mass economic migration. I think we are going to have to see a lot more of this before we see someone dim the sun.

Are there ways this could be done with rapidly biodegradable materials, such that e.g. it would need to be continually done year after year or else the sky would return to the exact same state it was in before? Also, living in Arizona with 120F/49C summers, I sure wish someone could come up with some geography-wide sunshade!

I guess that will need to be after they stop growing the city forever, and stop paving the earth of my state with black asphalt and concrete, and stop giving all our groundwater to lettuce and alfalfa farming to be sent out of the state or country entirely.

Not sure if you consider sulphur biodegradable, but it will need to be done continually, or else the effect will disappear.

It says in the article it only lasts a year, so its an adjustable stop-gap.

This is covered in the article, and comes with its own trade-offs:

> Sulfur disappears from the atmosphere quickly - it rains out after about a year. This means that once we’ve started SRM, it’s dangerous to suddenly stop. We need to keep spraying particles, all the time. If we suddenly stopped, the warming would spring back rapidly, causing a bad temperature shock. The correct way to stop is a gradual phase out.

Thank you for quoting it! For some reason the link won't load for me yet.

Sulphates have a cooling effect and drop out of the atmosphere. There was recently a push to remove the sulphate content in the fuel used for cargo ships from 3.5% to 0.5%, and as the sulphates dropped out of the upper atmosphere the water in the Atlantic warmed significantly. Turns out we had been unintentionally doing geoengineering that was counteracting some of the affects of climate change. The downside is that sulphates are deleterious to human health, causing asthma.

It's possible a sufficiently motivated billionaire or even a somewhat wealthy millionaire could independently finance a project to inject sulphates into the upper atmosphere in international waters and have a measurable impact on global warming, although people with respiratory issues might not be too happy.

Rains out as acid rain.

What wavelengths of light would be reflected?

My understanding is that the way greenhouse gas induced warming works is that we have incoming solar radiation over a broad range of wavelengths.

Some of that ends up being absorbed by various things on the surface which heats them which causes them reradiate some of that absorbed energy as infrared.

Greenhouse gases absorb infrared, and so some of that reradiated energy that would have been radiated back into space gets trapped by those gases.

From a purely reducing warming perspective then it probably wouldn't matter much what wavelengths you are reflecting. Any light you stop from getting absorbed and turned into heat below would help.

But incoming radiation often does useful things before or instead of getting turned into reradiated infrared. For example it may be used by plants for photosynthesis.

It would seem then that if reflecting light in the stratosphere to reduce warming you'd want to try to avoid deflecting wavelengths that are important for photosynthesis or other useful things.

You'd want to pick wavelengths that don't do much other than just end up getting absorbed at the surface. Does sulphur do this?

I've been fascinated by marine cloud brightening, a related technology. I'd love to see that explored first, as it seems cheaper and lower impact. Still, if it was a choice between pretending that we're going to effectively mitigate climate change at this point without geoengineering, and darkening the sun, I'd say darken the sun.

I think I read somewhere the CO2 absorbed by ocean causes acidification which the ecosystem needs a bit of adjustment to live with.

I don't think the a sun shade would do anything for that.

That said the Simpson's quotes in this thread are making laugh enough that I'm starting to get onboard with this plan whatever my initial doubts.

Did some people start reading Neil's book, Termination Shock?

Are we seriously using fiction to argue against doing things in reality?

Probably too late with this comment, but from today's WSJ: "Scientists Resort to Once-Unthinkable Solutions to Cool the Planet"

Lends some support to the author's thesis. A little unsettling that the reflective SRM material in the WSJ article isn't sulfur (apparently) but something proprietary of undisclosed composition.

https://www.wsj.com/science/environment/geoengineering-proje...

well written. terrifying but practical.

hopefully calcium carbonate experimentation gets underway so we can learn about its effects.

Would this process work the same way climate change is warming? Because climate change, while on average increasing the global temperature by 1.5C, has pretty big variations in actual temperature decrease by region. It's important if you use sulfur to decrease the temperature that this decrease counteracts regional temperature increases and not just average global temperature.

It says in the article that it would need to be carefully done to have an even impact.

As I wrote, climate change is not even. Do we even have the theoretical basis for knowing how to do this so as to counteract regional climate change?

And somehow, in the US at least, we don't even have broad agreement that climate change is real, happening, and will dramatically adversely affect humans for centuries to come.

Anyone have any good resources or techniques for having honest discussions with friends and family that simply refuse to believe a problem even exists? Real solutions will only come once we admit there's a problem.

Sulfur is probably not the best agent to do it, but we know that it works from the unintentional ship fuel experiment.

In any case, if 2023 wasn't an exception, I'd rather have someone start a program this year. It can always be stopped or scaled down. And I am confident that renewable energy, electrification, and battery deployment will continue unabated anyways.

In terms of Murphy: "If there is a wrong way to do something, then someone will do it."

The simpler solution is build a damn lot of solar on Earth and use the energy to suck CO2 out of atmosphere. I did the calculations, it was something like the area of UAE equivalent solar to have enough energy to suck ALL CO2 from the atmosphere.

With floating solar farms in the sea, you also don’t need a lot of land and can avoid all of regulatory overhead.

Have we thought about impact on plant life? Like wheat? Seems like a bit of a problem for a solution like this. One might say that plant life literally evolved for the solar conditions we currently have.

The long term fixes for excess atmospheric CO2 are (IMO):

- Using energy more efficiently (e.g. insulating homes better instead of burning more fuel in the winter)

- Electrifying as many energy demands as possible (heating, ground transportation, materials production, chemical synthesis)

- Replacing fossil-powered electricity generation with low emissions sources: solar, nuclear, wind, hydroelectric, geothermal, tidal

- Accelerated silicate weathering for carbon dioxide removal (basically, crushing a lot of alkaline mafic rocks so they react faster to neutralize CO2 that's already in the atmosphere and the oceans)

The IPCC proposes carbon dioxide removal too, calling for "net negative emissions" to neutralize CO2 that has already been emitted [1], except they give examples of afforestation, reforestation, and bioenergy with carbon capture and storage as removal techniques. (I personally think that those are poorly scalable and will not make much headway compared to silicate weathering, but I'd be happy to be wrong.)

What about the transitional time before we get to "the long term?" The majority of global electricity still comes from fossil fuels. Most road vehicles sold today burn fossil fuels. Even after we reach the tipping point where most vehicles are electric, the old ones may continue to operate for decades.

In the meantime, CO2 that has already been emitted is trapping more energy from sunlight and raising temperatures. Once temperatures go up enough, there are bad feedback loops where e.g. tundra thaws, microorganisms start releasing the previously frozen carbon compounds, and we get vast new emissions from thawing regions even as direct human emissions fall. In other regions, temperate forests may dry out, burn, and transition to different biomes with lower carbon sequestration capacity.

That's why I think that solar radiation management will be needed. It can break the feedback loops where higher temperatures denude forests and release vast quantities of soil carbon. It doesn't directly reduce emissions or draw down atmospheric CO2, but it keeps temperatures down so there's time for the energy transition and CDR techniques to stabilize and reverse the atmospheric CO2 excess. A world with 550 PPM of atmospheric CO2 is bad, but a colder world with 550 PPM can be stabilized while a warmer world at 550 is going to keep going up even if anthropogenic emissions are slashed.

[1] "What are Carbon Dioxide Removal and Negative Emissions?" https://www.ipcc.ch/sr15/faq/faq-chapter-4/

Its not fair that you guys keep changing the funny titles after i come up with a zinger for them.atleast give me a day or two to make my dimsum jokes before you make it serious again,....

Good. I mean, not good good. But better than the alternative.

What a horrible idea. Equivalent of kicking out your ill child with a fever into the frosty night to "cool down" or ordering a diet coke to fast food meal.

I feel this article was basically daring Elon to do it.

Dimming the sun is like the alcoholic proudly proclaiming they'll be eating salads for lunch. It ain't solving the actual problem.

Even disregarding climate change, we are way past the point where 8 billion people can survive without modern industry. The same will be true for geoengineering in the long term. Remember, we are still in an ice age.

Maybe it's time we all take a personal inventory of our own practices and how they impact the survival of our species, the planet's entire biosphere, before the next generation asks us, "why did you not change yourself to stop this?"

We’d easily choose all out war to keep our kids comfortable long before we’d all choose to lead smaller lives.

We’re not going to hold hands and sing while we all pedal bicycles and live in highly dense housing - we’ll give the army flamethrowers and they’ll keep out the wave of “climate refugees” until we’re fully out of anything we can make napalm out of.

I pedal a bicycle. I live in highly dense housing.

Maybe you should also do what I do: meditate on just why exactly one turns into such a fatalist.

You can't force people to care. That's the whole problem. Everyone thinks their contribution isn't the tipping point and someone else could make a bigger impact. People won't significantly change their habits unless they are forced to.

We are already messing around Mother Nature with all the fuel burning and now you are double shafting it, what could go wrong?

Termination Shock by Neal Stephenson

Or the film Snowpiercer (based on a French graphic novel).

Thus solving the problem once and for all!

We would rather block the sun than reduce the military industrial complex by 10%, the world's largest polluter.

What could possibli go wrong?

> #2 - Billionaires are getting interested

Yeah! So that they can keep on destroying the planet for profit.

Doesn’t Elon Musk have the means and the cult like following to do this unimpeded?

Behold, the great filter

Let's hope these technocrat degenerates never come to that.

You'll get in trouble with Big Solar for disrupting their production!

Whether or not you believe in climate-change, the interesting discussion to me is that climate change is a convenient justification for power-grabs by wannabe dictators. I'm not so sure that the elite will be so ready to give up that lever of control by simply tinting the sky. We'll see, I guess.

Every threat to the status quo is either a convenient justification for such, or a conspiracy theory that a power grab will happen.

Is not "tinting the sky" a power grab in itself? And a pretty darn serious one at that.

It's amazing that this solution has not been considered more openly and widely until now. It's cheaper, more effective, and doesn't require draconian regulations or near-impossible expectations on human behavior.

It's also something that could be tested for a year. It's not irreversible. It would allow the undeveloped world a chance to achieve a piece of the global wealth pie.

Why are so many people (especially environmentalists and climate scientists) so opposed to this solution?

Because warming is just one symptom of the core problem, which is pollution.

The core problem is even worse, it's our inability to live in a closed system.

The sky belongs to everyone. Hard to get sign off from everyone on making a change to it.

You’re right.. and yet I don’t believe everyone got to vote on whether we should burn all those fossil fuels in the first place.

Since when has that stopped companies and countries acting in their own best interests?

SpaceX has launched thousands of satellites, and plans to launch many thousands more, polluting sky and space observation for everyone on Earth. This happened relatively quickly, and doesn't require approval from every country, unless they intend to offer service there.

Similarly, it's not far-fetched to imagine a scenario where a "benevolent" billionaire, as the article puts it, or a single country, could decide that SRM is a good idea, and just go with it. Countries still pump excessive amounts of CO2 into the atmosphere, and historically can't align on a single policy. Why would something like SRM be handled differently?

From the article:

> Crucially, the biggest problems with SRM are probably not yet known. The side effects of putting sulfur into the stratosphere could be some of the most consequential unknowns in human history.

> Why are so many people (especially environmentalists and climate scientists) so opposed to this solution?

Because it's just kicking the can down the road. This will cost Trillions which you might as well invest in a transition to clean energy now because you have to do it eventually anyway.

If the impact of climate chains looks like it's posing a risk to us as a species then perhaps blocking the sun temporarily is something that should be considered. Right now it sounds like there's still a chance that we could avoid the worst if we continue acting faster and faster. Pointing to a hypothetical sun shield decades in the future, now, is similar to pointing to practically unlimited CCS capacity sometime in the future just so we don't have to do anything drastic now.

where are you getting trillions from? this paper estimates it at 10b.

pure fantasy that the world will ultimately do the "might as well" there though. The world is moving on but we're running out of time to prevent things that are a lot worse than having to deal with acid rain and simply keep pushing sulhpur into the atmosphere and then slowly taper off the sulphur.

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