5 ms·

My personal preference is an inflatable sun shield method like these 10,000 kilometer-wide objects: "Self-deployed, extremely large low mass space structures" h

My personal preference is an inflatable sun shield method like these 10,000 kilometer-wide objects: "Self-deployed, extremely large low mass space structures" http://diyhpl.us/~bryan/papers2/space/Self-deployed%20extremely%20large%20low%20mass%20space%20structures%20-%202007.pdf http://diyhpl.us/~bryan/papers2/space/Self-deployed%20extrem... I don't think people realize how a lot of these problems are solvable for only a few billion dollars... It's an engineering problem, mainly. Someone just spends the money and goes and fixes the problem.

jpfed 8y ago
That's one great thing about sunshades- they can be implemented by just convincing a spacefaring billionaire or two instead of having to change policy / steer nation-states.
- ryandrake 8y ago
  Unfortunately, you still need to convince the billionaire that the project will make him into a 10-billionaire, otherwise he’ll just keep it in the bank, or bathe in it or whatever rich people do with all the vast piles of money they are sitting on.
  - makerofspoons 8y ago
    Perhaps there's the chance that they're interested in their legacy being saving the human race. There will probably be statues of them, schools named after them, and who knows what else if the plan succeeded.
throwaway5752 8y ago
How would this affect plant life and agriculture?
- zspade 8y ago
  Since this would be over the poles, agriculture would not be impacted. There would likely be a substantial impact to ecology of these regions, depending on size of the shade of course.
ergothus 8y ago
I'm skeptical - You've shown a proposal, not a reality. (and the proposal didn't even mention a "shield" that I saw, but I may have skimmed past it). I didn't see a price tag, nor a timeline. Money can boost research speed, but not remove the need entirely. Second, If the cross section of the earth is 1.2x10^14 m^2, one of these would...well, we don't know, because the link mentioned volumes and length (the 10k km is a potential "span length" and wasn't tied to being "one" of anything). I failed to find the cargo volume for a Falcon 9 or other rocket (everything is in mass) but I think it's safe to say that you're talking a lot of launches which clearly aren't trivial to do. Third, and most importantly, you've just decreased the amount of energy coming to earth. You've not solved the problem, you've changed it. I love tech, but I think it's worth noticing the ratio of times someone says "It's [just] an engineering problem" versus the number of issues that have been actually been solved in this way (seeing the problem, spending a boatload of money, seeing problem solved). Most of our industries are based on the fact that we KNOW they can grow into more, but figuring out how and the complications thereof are literally the work of countless lifetimes.
- Tuna-Fish 8y ago
  > Third, and most importantly, you've just decreased the amount of energy coming to earth. You've not solved the problem, you've changed it. Probably the most important advantage sunshades have over other kinds of geoengineering megaprojects is that they can be trivially (compared to their construction costs, that is...) turned off. If they turn out to be very harmful in some previously unforeseen way, we can choose to not have them anymore. That is not so for, for example, seeding lots of nutrients for algae over the continental shelf.
  - philipkglass 8y ago
    As others have noted, solar radiation management doesn't do anything to counteract ocean acidification. I still think that SRM of some sort may be necessary to stop runaway feedback loops like loss of soil carbon from thawing permafrost. The sunshade approach to SRM looks like it may have been devised like other big speculative space projects: "start by assuming that big projects in space are the solution, then find a problem to motivate that solution." (See also: mining helium 3 from the Moon.) Solar radiation management with reflective aerosols instead of space sunshades looks simpler and easier to me. Most importantly, SRM based on aerosols is incrementally scalable from small low initial investment/scope. The sunshade approach, like many envisioned large space projects, appears to require large "lumpy" investments before delivering any detectable benefit.
sandworm101 8y ago
>> for only a few billion dollars. Really? This isn't just a matter of putting a big ball of tin foil out there letting it go. What about the station keeping? How is this big piece of tinfoil going to stay in place? At these sizes, solar pressure and the buildup of static charges become huge issues. It is going to drift. It will need engines, power and fuel. Ion thrust would seem an obvious answer, but electrical/static issues may make a web of ion drives difficult. It will need either new tech or, at least, extensive testing of current tech before any attempt. = a great many billions of dollars. I'd rather see that money spent on solar panels.

jpfed 8y ago

That's one great thing about sunshades- they can be implemented by just convincing a spacefaring billionaire or two instead of having to change policy / steer nation-states.

ryandrake 8y ago
Unfortunately, you still need to convince the billionaire that the project will make him into a 10-billionaire, otherwise he’ll just keep it in the bank, or bathe in it or whatever rich people do with all the vast piles of money they are sitting on.
- makerofspoons 8y ago
  Perhaps there's the chance that they're interested in their legacy being saving the human race. There will probably be statues of them, schools named after them, and who knows what else if the plan succeeded.

throwaway5752 8y ago

How would this affect plant life and agriculture?

zspade 8y ago
Since this would be over the poles, agriculture would not be impacted. There would likely be a substantial impact to ecology of these regions, depending on size of the shade of course.

ergothus 8y ago

I'm skeptical - You've shown a proposal, not a reality. (and the proposal didn't even mention a "shield" that I saw, but I may have skimmed past it). I didn't see a price tag, nor a timeline. Money can boost research speed, but not remove the need entirely. Second, If the cross section of the earth is 1.2x10^14 m^2, one of these would...well, we don't know, because the link mentioned volumes and length (the 10k km is a potential "span length" and wasn't tied to being "one" of anything). I failed to find the cargo volume for a Falcon 9 or other rocket (everything is in mass) but I think it's safe to say that you're talking a lot of launches which clearly aren't trivial to do. Third, and most importantly, you've just decreased the amount of energy coming to earth. You've not solved the problem, you've changed it. I love tech, but I think it's worth noticing the ratio of times someone says "It's [just] an engineering problem" versus the number of issues that have been actually been solved in this way (seeing the problem, spending a boatload of money, seeing problem solved). Most of our industries are based on the fact that we KNOW they can grow into more, but figuring out how and the complications thereof are literally the work of countless lifetimes.

Tuna-Fish 8y ago
> Third, and most importantly, you've just decreased the amount of energy coming to earth. You've not solved the problem, you've changed it. Probably the most important advantage sunshades have over other kinds of geoengineering megaprojects is that they can be trivially (compared to their construction costs, that is...) turned off. If they turn out to be very harmful in some previously unforeseen way, we can choose to not have them anymore. That is not so for, for example, seeding lots of nutrients for algae over the continental shelf.
- philipkglass 8y ago
  As others have noted, solar radiation management doesn't do anything to counteract ocean acidification. I still think that SRM of some sort may be necessary to stop runaway feedback loops like loss of soil carbon from thawing permafrost. The sunshade approach to SRM looks like it may have been devised like other big speculative space projects: "start by assuming that big projects in space are the solution, then find a problem to motivate that solution." (See also: mining helium 3 from the Moon.) Solar radiation management with reflective aerosols instead of space sunshades looks simpler and easier to me. Most importantly, SRM based on aerosols is incrementally scalable from small low initial investment/scope. The sunshade approach, like many envisioned large space projects, appears to require large "lumpy" investments before delivering any detectable benefit.

sandworm101 8y ago

>> for only a few billion dollars. Really? This isn't just a matter of putting a big ball of tin foil out there letting it go. What about the station keeping? How is this big piece of tinfoil going to stay in place? At these sizes, solar pressure and the buildup of static charges become huge issues. It is going to drift. It will need engines, power and fuel. Ion thrust would seem an obvious answer, but electrical/static issues may make a web of ion drives difficult. It will need either new tech or, at least, extensive testing of current tech before any attempt. = a great many billions of dollars. I'd rather see that money spent on solar panels.