Solar Shields III
7 Dec 2012
Localized models of geo-engineering of Solar Shields are gaining some ground .
See Appendix II . Partial sun-umbrellas can work .
The possible tech is discussed in Appendix I .
This is all rather old technology . It can be done now (well , about 5 years) .
The major problem was and is political . Who is going to determine whose rainfall , weather , etc ?
Using technology as set out in Appendix I , private companies can easily present a fait accompli while governments demonstrate their dithering incompetence .
This is obviously a Commons . The commons of near-space .
And we have a mechanism of handling this in the Ostrum Commons without resorting to Empire or Anarchy .
See Appendix III .
Humans can either farm the planet , or die in their own effluvium .
They have the tools .
If they do not have the will , they , their children and their grand-children will die miserable deaths , choking on their own wastes , knowing that they could have prevented this .
You know those “they” . Everybody except you .
And so it goes .
Solar Shield II
16 May 2010
Also known as Space-based reflectors , Sun shields , Sun umbrellas , Solar umbrellas .
These technologies are not safe , but are already in public domain .
But they are safer than most proposed geoengineering schemes in that they are dynamic and can be stopped fairly quickly if unforeseen deletrious effects occur .
Geoengineering is suddenly fashionable after the expected failure of protocols to limit CO2 emission on planetary scale . (Expected because of Tragedy of the Commons argument.)
See NewScientist of 3 Apr 2010 . There has also been a meeting at Asimolar , hopefully similar to a meeting at the same venue 35 years ago to get some ethical order in bio-engineering .
Republished in Addendum A below are some old arguments of mine.
This gives some fairly safe technologies to accomplish these aims .
Note that a major advantage is that these technologies do not need a consensus to be effective . Rich enough nations (USA , Russia , China , Japan , India) can implement them unilaterally or in small coalitions for a modest price . These nations also badly need projects like these to soak up the differences between wealth-creation and monetary-unit creation . See http://andreswhy.blogspot.com "Financial Crises 14 May 2010"
Be cool , Man .
See http://andreswhy.blogspot.com "Solar Shield"
See http://andreswhy.blogspot.com "Orion , Gaia needs you"
See http://andreswhy.blogspot.com "Training the Immune system"
Global warming is not just a short term problem . Barring catastrophe , human energy generation from fusion and non-solar sources will within a few centuries exceed the solar influx . We will need planetary air-conditioning .
(See Larry Niven's Puppeteer Planets)
At first , the simplest way is to put up an umbrella .
A simple solar Umbrella can be created by injecting Lunar reflecting dust into a hyperbolic orbit between the sun and Earth by mass-drivers on Luna .
The space elements of a moonbase and mass-drivers an be done with existing technology .
The Terran climate models needed for effective climate-control also exists , but can do with some refining .
The political control of an effective climate control system still needs some work .
The money , paradoxically , is the easiest . Big insurance companies (like Swiss Re , etc ) can easily fork up the estimated $60 billion this will cost . ( One big hurricane can cost $20 billion in damages .)
Later on it gets trickier .
At higher levels of planetary energy generation , Hilsch-tube lasers could directly pump energy out . A model that springs to mind is a fairly massive object (a few billion tons) in a perpetually skipping orbit . Propulsion would be by Hilsch-tube lasers (existing technology) and fusion (Orion-type existing tech.) More elegantly , the lasers would be boosted by fusion processes in the laser . This could be made made fairly fail-safe , so that there would be a nett energy loss to the planet . The matter-loss would have to be topped up ( comets?)
Of course , the same technology could be used to strip-mine a planet or sun .
Cascaded Hilsch-tubes were used in the South-African Uranium235-enrichment process for weapons purposes . A large physical or magnetic Hisch-tube cascade can be used like a mass-spectrometer to separate elements .
It would make a great booster for light-sails , or an awesome weapon . Also , cheap , pure elements
Time horizen : since all the above elements are based on standard physics , it can be done . Whether it will be , depends on humans .
Reusable reaction mass.
Imagine a 50 ton solar-powered launching satelite with a set of mass-driver rings in LEO at 18 000 mph in a West-to-East Low Earth Orbit .
Let it accellerate a 50 ton payload via mass-driver to 36 000 mph in some tangential direction .
In reaction , the Launching satelite will now orbit at 18 000 mph in an East-to-West direction .
Of course it is a bit more complicated than this , but the orbital mechanics are well within present technology (and really old maths) .
Docking new craft with the Launching satelite is also proven technology (ref International Space Station). This can then be relaunched in the opposite direction .
Essentially , the same reaction mass can be used over and over again , as long as it has been in orbit and an energy source is available (solar power , nuclear , etc).
All you need to do is get off-planet . Later on , the most valuable real-estate becomes in-vacuo mass (because you can use mass-drivers cheaply).
The orbit can be around any planet or sun .
The station need never decay .
One can imagine a Solar System ( at various ages ) with literally millions of millennia-old booster-stations in various solar and planetary orbits , each of various technological levels of development . They are inhabited , of course . Throw in some collapses and a singularity or two .
The political system and races will be quite fragmented .
Alien invaders would only consider a system with a developed transport infrastructure and fragmented culture .
This stellar signature should be quite distinct . The end result should be a Dyson-sphere or Ringworlds . But the intermediate stages will vary considerably .
They should also be observed more easily .
Jupiter class worlds will be moved closer to the sun for more efficient dismantling .
Planetary blobs and ringworlds should be observable by striations . Technological ramp-ups up waste-energy dispersal should be measurable if there are handy gas-clouds of various distances nearby . Reflections of planetary laser-heat dispersals varying over time might give a clue .
As can be seen , arriving at the optimum Dyson sphere stage will be outmatched by the number of civilizations either en-route or become agley .
To quote a Sol humanoid , each happy civilization is the same , but each unhappy one is unhappy in its own way .
Happy universes !
Some new models.
Localised sunshade could stop Arctic melting
• 18:00 21 October 2012 by Michael Marshall
• For similar stories, visit the Climate Change Topic Guide
If we have to hack the planet, we could at least do it with some finesse. Some of the problems with geoengineering could be fixed by targeting specific regions of the planet, rather than cooling everywhere equally.
A rough modelling study offers a crude blueprint for how to save the Arctic ice cap, but raises questions about who decides which areas to save.
Devised to stop climate change if attempts to cut greenhouse gas emissions fail or are insufficient to cool the planet, geoengineering schemes range fromsucking carbon dioxide out of the air to "sunshades" that block incoming sunlight.
Sunshades produced by injecting aerosols into the stratosphere have received the most attention as they could be a cheap way to cool the planet. But they are far from perfect.
Models show that no sunshade can restore both temperature and rainfall to their preindustrial levels. What's more, while average global temperatures could be restored, there would be regional differences. As a result, nations would probably disagree over how much geoengineering to do.
In a bid to reduce these trade-offs, Douglas MacMartin of the California Institute of Technology in Pasadena and colleagues simulated a more regional approach. They set up a simple climate model in which carbon dioxide levels were doubled, which is expected to happen in the second half of this century.
Next they modelled three different geoengineering scenarios: a uniform global sunshade, one sunshade over each pole, and a whole-planet sunshade that was thickest over the North Pole and gradually thinned as it spread over the equator and southern hemisphere. They also varied the time of year the sunshades were up.
Friendly local geoengineer
The team found that the regional geoengineering approaches gave better results. A uniform global sunshade left some regions sweltering while others were too cold. But with the regional solutions, these disparities were reduced.
To see if it was possible to restore the Arctic sea ice, which is rapidly melting, MacMartin tried switching a sunshade on above the Arctic during summers only. He found this could restore the Arctic sea ice to its preindustrial extent, while also bringing average global temperatures and rainfall close to their original levels.
"People complain about setting a global thermostat," says MacMartin. "That's not the right way to think about it. It's an engineering problem."
Tim Lenton of the University of Exeter, UK, points out that current climate models are nowhere near good enough to make such conclusions. While they do a reasonable job of predicting temperature changes, they give wildly differing predictions for rainfall. As a result, it's not clear what geoengineering needs to achieve in terms of precipitation.
Lenton is particularly sceptical about the claims for restoring Arctic sea ice, as the model MacMartin used distorts the geography of the North Atlantic to simplify its calculations.
MacMartin admits that his simulations are "idealised". In the model, he simply turned down the sunlight over different regions of the Earth. In reality, aerosols move around so this level of control may not be possible.
Nevertheless, his results open the possibility of a more sophisticated form of geoengineering. By combining different techniques, it may be possible to tailor the future climates of different continents, although MacMartin cautions that any change in one region will have knock-on effects elsewhere.
This will make it harder for countries to agree what to do. Lenton points out that nations would have to decide between them which aspects of the global climate to preserve. "Is protecting the sea ice more important than protecting the Indian monsoon?" he says. "Who decides? It inevitably turns into a power game."
In an attempt to reduce the inequalities caused by geoengineering, Lenton argues, MacMartin has uncovered even more complicated inequalities that, if anything, make the geopolitical problem worse.
Journal reference: Nature Climate Change, DOI: 10.1038/nclimate1722