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Can we start discussing geo-engineering strategies more seriously? Andrew Yang's mention of space mirrors was derisively put-down, but can someone lay out why it isn't a good idea?

If SpaceX and others continue to make getting things into orbit much cheaper, what's the argument against putting highly reflective barriers in the Lagrange point, which is a point constantly between the Earth and the Sun. If we deflected even 1% of sunlight, wouldn't that be enough to lower temperatures back down towards 0 C, as opposed to +1.1 C where we are now?

And why not focus the sunlight-blocking onto the poles, which we need to maintain our climate and which are experiencing even more rapid change?

Is the argument against these strategies that relying on geoengineering will take focus away from transitioning our energy system? I just think we have no hope of transitioning our energy system in time, emissions are STILL rising year over year...we have to think about how to cool the planet while we decarbonize our energy.




Well, for one thing, you would need to block out 2% of sunlight to counteract the warming effect that we've seen since the industrial revolution.

But more importantly, you are underestimating the scale. The earth is big, and L1 is far away. A device that blocks 2% of the sunlight at that distance would have to cover 4.5 million square kilometers, a disc that size would be larger than the moon, or about the size of the entire United States including Alaska.

It would also require engines that need to be constantly refueled, because solar wind, which is really strong at the scale we're talking about, would push it away in just a few months.

And the screen would need to be smart, because L1 is only quasi-stable. The actual point where there is zero differential gravity is, well, a point, and any deviation from that point will inevitably increase until the object eventually falls into a regular orbit, so to stay there you need to be constantly monitoring your own orbit and correcting for deviations. Only L4 and L5 are self-correcting (which is why there are no known natural objects at L1-3 of any two-body system)


Would you need a single mirror? Many smaller mirrors sounds more plausible.


The number of mirrors isn't the problem. No matter how many pieces you slice it into, you have to achieve that quantity of surface area somehow.


You'd still need to lift them to L1 and equip them with propellants to counter the solar wind.


Given the depth of our knowledge of the interlinked dynamics of earth's ecosystem, pulling out Geo-engineering is like practicing brain-surgery by whacking a baseball bat to the side of the patient's head.

But hey, I get it. There are profits to be made in Geo-engineering, while no-one will get rich quick from abstinence, right?

I have said this for years. We will not take any action until it is too late, and then we will speed up our demise by trowing a 'Geo-engineering' hail-Mary (using engineering in the name is supposed to give it some merit it doesn't deserve)


When we look back in 50 years, I believe we'll see this as a time of incredible growth and discovery. Kind of how I look back on the space age now, the moon landing. The space program was almost a complete disaster, but instead it inspires generations.

Yes, let's talk solutions! It you don't like one of these solutions, come up with a better one. Anything but working on solutions is an excuse (i.e. complaining about people that aren't on board or trolls). Don't miss out on the big adventure.


Isn't that solution a bandaid?

Geoengineering imply that we are better than nature. We mess up Earth and we're going to fix it not by stopping pollution and our bad habits, we'll just create this bandaid.

It's much more of a gamble too.

We only have one Earth. Why can't we just pollute less? And address the problem directly. We use too much oil and are throwing plastic into the sea.

Your proposed solution sounds like it cost a lot. I think there are other cost effective ways to go address this problem and can lead to a win-win for everybody (well except for oil industry).


Bear with me.

One of the criticisms of Javascript developers is that they make things slow with bad practices and by adding needless frameworks to their apps. Then in order to solve that problem, they bolt additional frameworks on top to do complicated, hard-to-debug compilation steps, or to optimize specific code paths, or to defer loading to make things appear faster than they are.

What they don't realize is that all of the bloat in their apps came from things that seemed like good ideas at the time. If they were actually smart enough to engineer their way out of the problem, they would have also been smart enough not to engineer their way into it in the first place. So when they add their new speed-solutions on top of the existing codebase, often they introduce new bugs or limitations that end up making their app even worse in the long run.

Wherever possible, a solution should not be significantly more complicated than the problem. Occasionally, you can get genuine speedups from adding new libraries, but this should not be treated as the norm. Usually, the best way to make apps faster and lighter is to stop using so much stuff.

And as it is with Javascript, so too is it with climate change and geo-engineering projects.


Space mirrors are almost impossible to build right now.

Shadowing 1% of the earth would require 10 million tons of mylar foil, which would be 100,000 launches with SpaceX's yet to complete Starship at a payload capacity of 100t (as it was announced, seems to be down a lot for the prototypes) to low earth orbit. That's not doable yet - and it is just the problem of launching the mass, nothing else.


I watched SpaceX' Starship update earlier. Maybe space mirrors are not that crazy anymore.


well spitballing.. does it have to be in space? and what if we split the mirror into many smaller ones?

what if we launched a bunch of mirrored balloons?


That would probably also have the effect of reflecting some of the energy leaving Earth back down onto it, essentially increasing the greenhouse effect.

Also, assuming you need to reflect 2% of the incoming light, and using 8ft diameter balloons, you would need approximately 2,744,628,480,000 balloons.


Why think so small? Do something like this

{1] https://en.wikipedia.org/wiki/Cloud_Nine_(tensegrity_sphere)

combine that with the ideas of

[2] https://en.wikipedia.org/wiki/High-altitude_platform_station

and PROFIT!


What impact does this have on photosynthesis?


...and who will pay for that? A lot of people are upset when the government spends money to help solar panel industry, a proven technology that generates electricity right now.

I don't think these people will open their pockets to build an unproven space mirror to solve a problem they vehemently refuse to acknowledge in the first place.

* Also it won't do shit to solve ocean acidification, another serious aspect of Global Warming.


Or we could plant more trees. Seriously, of all the crazy carbon capture ideas proposed, planting trees still beats them for effectiveness.

Geoengineering will make lots of money for whoever ends up doing it, but on the scale we are talking about they are mostly infeasible decades long projects that will take why more money and political will than just stopping emissions.


Is the tree thing viable? Can we plant enough trees and keep them long enough from burning or rotting?


As long as it doesn't get too hot from emissions first. If we get up to +3C or +4C we are talking about loosing habitability in large parts of the world for trees (and probably humans).

https://www.nationalgeographic.com/environment/2019/07/how-t...

It's just land the size of the United States to erase our last 100 years of emissions. Trees have the side benefit of being neutral or useful in many contexts. There is plenty of room.


Any geo-engineering strategy that's more expensive than carbon sequestration or significantly riskier is a non-starter.


I feel like geo-engineering more clouds is more feasible than giant space mirrors. Not sure what that would do to weather patterns though.




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