The problem with geo-intervention

Victor Venema, who does work on climate change, has a post up in which he explains that he thinks taking climate geo-intervention seriously is probably unavoidable, and we may as well start investigating it now.

But he does explain a key practical problem with the concept, as follows:

We would have to keep on managing the insolation for millennia or until someone finds a cheap way to remove carbon dioxide from the air. The largest danger is thus that humanity gets into trouble over these millennia and would no longer be able to keep the program up, the temperature would jump up quickly and make the trouble even worse. Looking back at our history since Christ was born and especially the last century, it seems likely that we will be in trouble once in a while over such a long period.

This danger could also be an advantage, just as the mutual assured destruction (MAD) with nuclear arms brought us a period of relative peace, the automatic triggering of Mad Max would force humanity to behave somewhat sensibly and make people who love war less influential.

My impression is that the main objection from scientists against geo-interventions is their worry about creating such an automatically triggered doomsday machine. Those people seem to think of a scenario without mitigation, where we would have to do more and more Solar Radiation Management. While carbon dioxide accumulates in the atmosphere over millennia, the stratospheric particles (after a volcanoes) are removed after a few years. So we would need to keep adding them to the stratosphere and if we do not reduce greenhouse gas emissions increasingly many particles. 

 I am surprised that he does not also consider that natural disasters effectively beyond human control might put a serious hole in maintaining the necessary work - a seriously large asteroid strike, for example, would have economic and society disrupting consequences that I doubt anyone can forecast.  While it won't likely be the end of humanity (it's a big planet), and the dust it throws up would initially cool the place, perhaps to crop destroying and famine inducing levels, when the sky clears enough again the world economy may take a long time to recover before large scale geo-intervention can resume.   This scenario would involve initial disaster from sudden darkness and lingering cold weather, to a reversal where the temperature climbs rapidly to dangerously high levels.

I would much prefer to not have the dangerously high temperatures a possibility.

And besides, at an ecological level, no one knows how ocean acidification is going to pan out.  Lots more algae, sometimes of the poisonous variety;  key crustaceans in the ocean food chain (pteropods) dying out;  oxygen low areas of the ocean that can support little sea life of any variety - these are all realistic predictions of increased CO2 in the atmosphere and oceans, and keeping the temperature down alone won't solve them.

So, I will remain a skeptic of this band-aid approach to dealing with climate change and CO2 emissions.