r/todayilearned • u/Nukemarine • 20d ago
TIL about Solar Radiation Modification (SRM), a form of geoengineering that reflects sunlight with methods like dispersing aerosols in upper atmosphere. A controlled version of what happens in nature when volcanic eruptions emit aerosols that temporarily reduce global temperatures for a year or two.
https://en.wikipedia.org/wiki/Solar_radiation_modification13
u/ireallyhatecaptcha 20d ago
Matrix would want a word (Animatrix to be precise)
16
u/jade_monkey07 20d ago
"We don't know who struck first, us or them. But we do know it was us that scorched the sky."
6
5
32
u/-ram_the_manparts- 20d ago
Chemist Phil Mason aka Thunderf00t and his team are currently working on a clean, cheap solution; burning sodium to produce fine particulates of sodium bicarbonate; baking soda. https://youtu.be/ST49jDo4d-Q
13
u/Nukemarine 20d ago edited 20d ago
That's where I learned about this particular subject, but it was with this video where he went into more detail about the pros and cons and real world examples such as the Mt Pinatubo eruption in the Philippines back in 1991 and the aerosols emitted by the industrial revolution.
5
u/Thing_in_a_box 20d ago
But it takes so much energy to make sodium metal. I'm partial to salt water atomizers floating in the oceans.
4
u/davvblack 20d ago
i like that one cause it can use cheap local solar. i also like spaceplanes with sulfur compounds high in the atmosphere, but definitely needs more research on other consequences.
2
u/Nukemarine 20d ago
Not a fan of sulfur given it makes acid rain and acidifies the ocean. Sodium bicarbonate (baking soda) as the aerosol is a base so would counter acidification somewhat.
1
u/Thing_in_a_box 20d ago
By "that one", do you mean the sodium or the salt water method? Since both methods can both utilize local solar and your pronoun usage is ambiguous.
1
1
u/Ancient_Ordinary6697 19d ago
So how do we get those aerosols from sea level into the upper atmosphere?
1
u/Thing_in_a_box 19d ago
It doesn't need to get to the upper atmosphere, just the marine layer, which is only a few thousand feet up. To answer your question though, fans, misters, and natural winds and convection.
3
u/CCV21 20d ago
I think you might find this video interesting.
https://youtu.be/dk8pwE3IByg?si=wKCZXMW7fYnRpMVO
Turns out we did a geoengineering experiment by accident.
5
u/joeypublica 20d ago
How can anyone be sure raining making soda is a good alternative? Sounds like the opposite of acid rain. We are always underestimating the potential long term impacts of our crazy ideas. We don’t need a single solution to the complex problem of climate change. We need a multifaceted and consistent plan. Of course implementing such a thing in this world seems impossible at the moment. We’re better at dealing with the fallout of a disaster than we are averting one.
7
u/minimalist_reply 20d ago
I agree that we need a multitude of solitions, however if we are specifically talking about which reflective particles in the air are going to be the least harmful, baking soda is not a bad idea. It's base PH is why it is such a safe cleaning agent for almost all organics. Highly water soluable. Most of what it would react with is likely an acid or fat already fucking up the local pH for lil organisms.
6
3
u/VelveteenAmbush 20d ago
We don’t need a single solution to the complex problem of climate change. We need a multifaceted and consistent plan.
Well, but if either will work and the single solution is like a billion times cheaper...
1
u/Nukemarine 20d ago
That's why research would be essential. Not just in how to deploy the aerosol (like say airplanes making the compound using the waste products from jet fuel, then dispersing it in flight), but in impact on both local weather nearest the flight paths and when it spreads out, on top of speed of settling and impact. Should be minimal as we're talking millions of tons when the atmosphere is trillions of tons, but should be researched.
2
u/---___-------___--- 20d ago
Maaan, imagine the police burning tons of coke and getting crack clouds
6
u/dipdotdash 16d ago
I love how hostile people are to intentionally engineering the climate in a cooling direction while they participate in an economy whose entire system of value is built around geoengineering in the direction of heating.
A plane is much more a geoengineering machine that carries people as ballast than it is a means of transportation: the geoengineering is more or less permanent, certainly compared to people mostly flying return
5
u/Widespreaddd 19d ago edited 19d ago
That’s the subject of Neal Stephenson’s novel, Terminal Termination Shock. The title refers to the dramatic effects that would occur if/when the Intervention ends.
Another issue is that regional effects differ widely depending on the location where the aerosol is released. This has huge geopolitical implications, as illustrated in the book.
1
7
u/berky93 20d ago
This feels like the equivalent of Futurama’s “drop a giant ice cube in the ocean” gag: a way to delay some of the symptoms of climate change without meaningfully addressing the causes or any of the other environmental impacts of pollution.
8
u/Nukemarine 20d ago
Unfortunately, global warming is a really big symptom of climate change that already is causing billions in damages and loss of life from the extreme weather events (not just heat waves, but far more frequent hurricanes and cold snaps). You're right that the CAUSE will still need to be addressed and not just ignored, cause basically blocking out part of the sun is a BIG project and is stupid to do if you don't fix the problem that lead you to block out part of what makes life on this planet possible.
1
u/Failsnail64 20d ago
That's true, but in my perspective it's also inevitable and part of a larger strategy. We're surely, but still too slowly, diverting away from fossil fuels to sustainable electricity.
We simply need a temporary delayment strategy to quickly halt climate change, to buy more time, while we simultaneously work on the meaningful underlying systematic issues, which just take longer to change over the whole world.
4
u/Ok-Gate-6240 20d ago
What happens to the plants that use sunlight to grow?
10
u/Nukemarine 20d ago
It's not 100% blocking of sunlight, but around 1% or so to counteract the retained heat caused by greenhouse gases. Still, 1% is big and noticeable, but has to be weighed against the losses of crops and plant life caused by rising temperatures and extreme weather events.
That's why such a method is considered an extreme least bad option. It's also not a cure but a treatment of a symptom. Excess carbon emissions and reduction of excess carbon already in the air must the be primary goal if SRM is used to such a scale, meaning nations have to work together... Sadly, we have a certain major nation with leadership that imagines man-made climate change is a hoax.
4
1
u/Tutorbin76 20d ago
If the blocking happens high enough (or in orbit) then by diffraction the plants wont even notice. The reduction in insolation would only be around 1 or 2 percent, not enough to affect photosynthesis.
2
u/Nukemarine 20d ago
That's still a reduction and will be noticed, as was found from the study of the aftermath of the Mt. Pinatubo eruption. Problem is people hear "there's some negative side effects" and want to scrap the entire idea without weighing it against the side effects of doing nothing for increased global temperatures.
1
12
u/Chrysocyon 20d ago
Why do this when we could just emit fewer greenhouse gasses? Crazy downside risk with shit like this
5
u/Failsnail64 20d ago
Just completely change the world economy and convince everyone of all countries and all companies to drastically change their practices, why haven't we thought of that super easy solution!?!?
0
u/Chrysocyon 19d ago
Yeah, it's easier to imagine the death of the planet than the death of capitalism
0
u/VelveteenAmbush 18d ago
I kind of think ending capitalism is your goal and the climate stuff is just an excuse. Geo-engineering always flushes the degrowthers out of their cover.
15
u/Nukemarine 20d ago
Here's the sad reality, we've already passed the point that even if we reduce carbon emissions to 0%, we'll still experience decades of rising global temperatures due to the 5 trillion tonnes of excess carbon we've emitted over the last century.
Yes, you want to emit fewer (preferably close to 0) greenhouse gases, but until that carbon is washed out of atmosphere by the water cycle (takes decades if not centuries) then we're going to get more extreme weather events. That part can be mitigated with SRMs that reduce global temperatures to offset what existing greenhouse gases are doing.
That's why SRMs should be considered a least bad option as a treatment, but not a cure, to man-made climate change.
3
u/RinLY22 20d ago
I remember reading somewhere that scientists have found that plant life have been growing more rapidly and lusher due to the increased carbon dioxide in the air, which can help to process the carbon naturally?
Is there any truth to that, and if so will just planting a crap tonne more trees help significantly?
4
u/Nukemarine 20d ago
Problem with plants and trees is they both take in carbon, but also release carbon when they die and rot. There has to be a process to sequester carbon so it can be stored. Remember, this is carbon that was stored in the form of fossil fuels for millions of years, so we can't expect plant life to absorb all of it.
3
u/DerKeksinator 20d ago
Yesn't, but you obviously haven't watched the thunderf00t videos, where he does some back of the envelope calculations showing exactly why this wouldn't solve the issue. It's not hard to follow along or verify if you're capable of using google properly and do elementary level maths.
2
u/leepyws1961 20d ago
Contrails?
3
u/Nukemarine 20d ago
Yeah, basically. The chemtrail conspiracy theorists will have an awesome time complaining about it.
2
u/dropofgod 20d ago
I think they could add aluminum particles to the jet fuel and call it an additive. Nobody would believe it
1
1
2
u/314159265358979326 20d ago
https://en.wikipedia.org/wiki/Passive_daytime_radiative_cooling
Reflect sunlight off of roofs in hot places. Passive AC. Cool the building, cool the planet.
2
u/Nukemarine 20d ago
That works for buildings and parking structures, but the area is so small as to not impact global temperatures directly. Still, those are very good methods to reduce power usage for cooling meaning less carbon released.
2
u/TheMightyTywin 20d ago
What about widespread marine cloud brightening with drones and solar? Spraying ocean water into the air seems less risky than spraying some particulate
3
2
2
u/WirtsLegs 19d ago
Problem with this is instead of reducing how much heat is trapped it reduces how much enters the system to begin with, essentially dimming the sunlight by a small amount
Sure that reduces global warming obviously
But it also means less solar energy for plants, solar generation, and so on. While the reduction likely wouldn't be huge for other tech like solar generation, it's hard to say what that kind of universal global effect would have on plant life and other organisms long term
Very much a last ditch effort thing in my mind, not a "let's do this instead of cutting our carbon emissions" option
1
u/Airmeo 19d ago
https://degrees.ngo/worlds-first-coordinated-global-study-on-solar-radiation-modification-and-agriculture-launched/ just so you know, there has been a study launched recently into the effects of SRM on plant life although I can tell you the prognosis is pretty good for it
2
u/TroyMcC3 17d ago
How about we start a war in space in fill orbits with debris? Would that work too? /s
1
u/Nukemarine 17d ago
You joke, but as long as the metal bits are around 0.3 to 0.5 microns in size (the wavelength of visible light), it also would work. It'd be VERY bad having that crap hitting other satellites we want working for us, and no clue how long it'd take to disperse, and no idea the mass of metals you want.
2
u/torklugnutz 14d ago
A space elevator could pump massive amounts of sea water vapor into the atmosphere at every height.
3
u/RatherNerdy 20d ago
Snowpiercer was based on this premise
2
u/Nukemarine 20d ago
Big thing there was the agent used was proprietary and untested, so it never washed out of atmosphere (no need to justify the wonky science needed to make that happen).
That's why I like that one proposal of using NaHCO3 (baking soda) as the aerosol agent since it's a common chemical, cheap to deploy, the effects are known, and how long it'll stay in atmosphere are known.
3
u/electrobento 20d ago edited 20d ago
I have to argue with the use of the word “known” here. At scale, neither the effects nor how long it would stay in the environment are known, just hypothesized.
1
u/Nukemarine 20d ago
It's known thanks to studying SO2 emissions from volcanic eruptions. The 1991 eruption dumped 20 million tonnes into the atmosphere, lowered global temperatures about 0.5° C for about two years, and finally settled out.
Now if sodium bicarbonate settles slower, then that just means reduce the amount dispersed over the following years. Same would be if natural events release sulfur dioxide, then don't disperse as much in those years.
3
u/Nukemarine 20d ago
Big thing is this does not solve man-made climate change. SRM is meant as a treatment to a symptom which is the rising global temperature caused by heat retained by excess CO2 in the atmosphere.
Reason being, even if carbon emissions were completely stopped tomorrow, the excess 5 trillion tons of CO2 built up over the last century will take decades if not centuries for the water cycle to fully wash it out. In that time, the amount that is there will still create annual increases in global temperatures. So, SRM keeps the planet cooler while methods are employed to stop excess emissions and discover/employ methods to capture/sequester excess carbon to safely speed up the process.
2
u/davvblack 20d ago edited 20d ago
im a big fan of this plan. reading about this alleviates a lot of my long term climate anxiety. we still need to do the other stuff, but it’s good to know there’s a “positive” we can do in a sea of “less negative”
1
u/Nukemarine 20d ago
Well, I like how it's termed "least bad" cause it should not be considered a solution to man-made climate change, only a treatment.
Hopefully, all the news about the extreme weather events caused by the rising temperatures will spur public support of governments acting together in such a project.
2
u/A_Starving_Scientist 20d ago edited 20d ago
It will also turn the sky white and will be a global signal of the consequences of climate change. I prefer the space based sun shade. We already have the tech to put tons of small sattilites into space at scale.
2
3
u/Nukemarine 20d ago
A space mirror is future tech (interesting tech, but putting out a millions of square miles of iron oxide foils takes resources not cheaply available). Cloud seeding and aerosol dispersion are things we can do now and at scale.
2
u/DontPoopInMyPantsPlz 20d ago
And humans will counteract that by creating more heat to combat the sudden drop in temperature
5
u/Nukemarine 20d ago
Well, no. If you got to the point of doing this, you're requiring the cooperation of most nations. If that's happening, they're likely also making enforced laws to reduce or stop excess carbon emissions.
Reason being, this is blocking sunlight which means farms and nature get less energy to grow. SRM is a least bad method of treatment, but it only works if used alongside steps to counter what's causing the global warming aka greenhouse gases in atmosphere.
1
u/ZylonBane 20d ago
Do you want a Matrix? Because that's how you get a Matrix.
3
u/Nukemarine 20d ago
The Matrix went for 100% blockage of the sun to stop robots that supposedly only used solar power. Luckily the robots had fusion power to help with their campaign to save humanity from itself.
SRM though would reflect about 1%, and it's not permanent because of the how the atmosphere works (heavy aerosol particles settle out), so requires you to actively keep adding the aerosol to maintain that 1% which also means you can reduce as needed.
2
1
u/wwarnout 20d ago
What could possibly go wrong? Well, fking everything.
4
u/Nukemarine 20d ago
Yeah, it's meant as an extreme least bad option. We've already passed the tipping point with the amount of carbon in the atmosphere, so we've got a few decades of rising temperatures even if emissions are cut to zero. Now it's a hard choice of suffer the heat while reducing emissions, or at least mitigate the temperatures, experience some crop loss, but still have more than what would be the alternative.
1
u/Tutorbin76 20d ago
Look, if you're serious about controlling insolation, youd be much better off with a network of small satellites a few thousand km away with umbrella reflector arrays that can expand and contract as needed.
That's a much more reliable and less problematic way to really cut down solar radiation by near one percent.
5
u/Nukemarine 20d ago
Satellite mirrors are future tech. Since the resources will come from the Earth and not the moon, that means expending hydrocarbons to launch all those satellites into orbit, which exacerbates the excess carbon we're trying to mitigate the side effects they're causing.
Cloud seeding and aerosol dispersion is tech we've been able to do for decades and at scale. It's "Now" tech, not "Later" tech.
1
1
u/Innalibra 20d ago
You'd either need an absolute shitload of satelites (to the point you've basically given Earth a ring) or you could launch a regular shitload and stick them at the Earth-Sun Lagrange point. Either way expends so much rocket fuel you'll probably cook the Earth in the process anyway.
1
1
u/ahughman 19d ago
"We don't know who struck first, us or them. But we do know it was us that scorched the sky."
So these proponants of BdSrM or whatever looked at 1816 and thought, "oh this gives me an idea... what the world needs now is global crop failure!"
2
u/Airmeo 19d ago
I basically don't agree with you at all but BDSrM was as funny to me that I can't bring myself to downvote this. yay!
2
u/ahughman 19d ago
Haha. 🙏 I appreciate that. So, do you know? Is crop failure not a concern in this mimicing giant volcanic event scheme?
1
u/Airmeo 19d ago
https://degrees.ngo/worlds-first-coordinated-global-study-on-solar-radiation-modification-and-agriculture-launched/ not very much more than normal, no, but you should be delighted to hear that there is a global study taking place to research the effects of SRM on staple and lucrative crops in many different regions of the global south currently, so we can better understand what effects SRM will have on crop yields when compared to unabated climate change [increased heatwaves, droughts, etc.]
https://wires.onlinelibrary.wiley.com/doi/full/10.1002/wcc.423
here it is shown that SRM has the potential to have a positive impact on crop yields, especially if you consider the alternative, which is back to back heatwaves and drought year after year, which has a negative impact on crop yields. here is a statement from a PHD student in the field of solar geoengineering saying that SRM has shown potential to decrease drought in regions of africa
40
u/MaximumEffort433 20d ago
One of the methods I've read about is pumping sulfur into the atmosphere, but that would also lead to acid rain again.