Will civilization survive?  A loaded question I suppose, and anyway, people, if alive, will always be doing something, and that by definition that is their civilization.  

But what WE are doing is unsustainable, and we will not be doing it much longer.  So yes, OUR civilization will go, will COLLAPSE--whether we like it or not--and it is not a question of SEEKING to destroy our civilization, which is actually doing that particular job all by itself.  

I do believe good thought, including scientific knowledge, might be used--and indeed should be used--to ameliorate the consequences of what is happening now.  But the SO2 scheme is at least a double-edged sword--if it does not have more edges than that--because its capability for harm is at least as great as for good, and depends critically on who studies it and implements it and when.  To be a back-up plan, used only in need, in a context where sustainability is actually happening (not our world) is totally different from introducing it in the fore, with--as is clearly the case for some--the intention that the transition to sustainability be evaded and postponed.  In this latter scenerio SO2 will make the catastrophe of transition worse.  

Your point 2) opens an evil scenerio that never occurred to me:  A world thick with smog but kept just barely cool enough by heavy doses of stratospheric SO2, which must be perpetually increased as CO2 loading of the atmosphere continues, until we find effects from precipitating SO2 (acid rain returns) becoming important.  

Perhaps this was anticipated in Marge Percy's "Woman on the Edge of Time."  

But you are wrong to imply that this can be continued indefinitely, and that to oppose it is to be pro-warming.  It would just be another stage in the death-slide.  

Are you asking how can we persuade people to avoid this scenerio?  It is surely worth doing.  

I suspect there is a good reason to oppose stratospheric SO2 injection intuitively.  And should we find un-intuitive, logical and fact-based reasons?  That is a good idea.  

Your scenerio of point 2) is reason enough to oppose, but there is no reason not to have more facts.  

Migeru read me right.  The snap-back is not the problem of the SO2 returning, which is separate and not argued here.  It is that using SO2 to allow greater CO2 loading will mean that when the SO2 comes out of the stratosphere, the global warming will be greater and sharper than it otherwise would have been.  

This creates a more desolate post-boundary environment.  

The Fates are kind.

I think that Gaianne isn't concerned about the effects of SO2 coming out (which it would do on a steady basis, regardless), but instead about the negative effects of losing its cooling effects all at once, causing abrupt warming that might well be more ecologically damaging than slow warming.

There is a valid concern here, though I think that Gaianne gives it too much weight for several reasons:

• First, treating the collapse of civilisation as certain claims more knowledge of the future than I think anyone can have at this point.

• Second, the scenario requires that a collapse be both world-wide and remarkably thorough, because putting SO2 in the stratosphere isn't very difficult. Since a generous estimate of the cost is 1/5000 of GWP, an economic collapse could be 99% complete, yet the cost would be no more than 2% of the remaining GWP. (And the job could be done with technology at the WWII level or less.)

• Third, I don't see any snap-back effects that are likely to be worse than the cumulative effect of decades of warm conditions, for example, polar melting.

(BTW, I usually avoid claiming that I know any particular person's unspoken thoughts and motives, or predicting that they will never reconsider an opinion. I'm much more comfortable making predictions that substantial groups will react in a particular way -- for example, I think that your prediction regarding Gaianne will surely prove true of many people.)

Words and ideas I offer here may be used freely and without attribution.

You make my point for me:  

In the absence of change, we enter the scenerio implied by technopolitical's point 2).  SO2 injected into the stratosphere keeps the Earth just barely cool enough.  Making no change, we keep releasing CO2 into the lower atmosphere at an increasing rate, as a by-product of continuing and expanding industrial civilization.  As a result, the amount of SO2 that needs to be injected into the stratosphere also increases, until the precipitating SO2 DOES become an environmental problem.  We have then achieved a world that is just barely cool, and multiply polluted.  

At what point do these extra problems add to the accelerating destruction of the biosphere to the extent that it ends human life support?  That time comes.  

Fundamental change is not only necessary, it is going to happen whether or not anybody likes it.  The only question is whether there is a way to choose the better, rather than the worse, changes.  

nobody will be around to give a fsck about it.

I don't favor policies of extinction.  

The Fates are kind.