Dateline December 2016
One of us calls attention to this paragraph in a news story on reducing incoming solar radiation:
"Geoengineering is like taking painkillers," said a writer. "When things are really bad, painkillers can help but they don't address the cause of a disease and they may cause more harm than good. We really don't know the effects of geoengineering but that is why we're doing this research."
I want to comment at three levels.
a short reply to the logic of the paragraph
a longer reply to what I think is the real elephant in the room, the reason this and every writer feels it necessary to include this caveat or something like it.
a dissertation on the causal chain that relates to global warming--it's sort of a five why's.
1) Short reply.
If we accept that CO2 is the cause of climate change, solar geoengineering does indeed address the symptom but not the cause. However, there are other forms of geoengineering like ocean fertilization that--we hope!--will address and draw down atmospheric CO2. I would suggest these are closer to a cure than to a painkiller, if any of them works.
2) The elephant in the room, the deep [and deeply felt] caveat.
With no more empirical evidence than a lifetime of watching, I see that, whenever major suggestions are made in the name of dealing with climate change, and sometimes even minor suggestions, a fear of unintended consequences is expressed; i.e., that we may cause more harm than good by monkeying with Mother Nature. Therefore we ought not to do whatever is under discussion--usually not even to research it--lest we upset a delicate planetary balance. The hidden assumption is, there's lots of time so we don't need to act yet, not 'till it's really desperate; another hidden assumption may be, the situation is not or will not get desperate. Or again, that our children will figure it out.
The trouble with all of those is, humanity has already been monkeying with Mother Nature [and you know what that makes us!] As Alan and others in this group have put it, the experiment is already going on [in the guise of business-as-usual] and it's badly out of control; the logic coming from that conclusion is, we need to do something. Doing nothing is not an option – it is actually suicidal.
The other assumption here, not so well hidden is, just stopping CO2 emissions will suffice and global warming will cease to be a threat forthwith. Then the logic of the 'moral hazard' kicks in, to wit, better not study geoengineering lest humanity take any plausibility of geoengineering as license to continue with business-as-usual. Well...
Our study convinces us that just halting all emissions, unaided by geoengineering, will prove lethal to humanity and to many other species as well.
At all events, nothing any one of us or anyone else has done has been able to halt business-as-usual and the concomitant rise of CO2 concentrations.
3) What is the causal chain behind global warming?
Why is there global warming? Because earth keeps more heat from the sun than is re-radiated back to space.
Why is that? Because too much solar heat is trapped by the atmosphere.
Why is that? Because there is too much CO2 in the atmosphere, and it's increasing.
Where does atmospheric CO2 come from? From natural sources and from humans burning fossil fuels. Natural sources are relatively constant but human use has increased disastrously.
Will the CO2 dissipate if we stop burning fossil fuels? Yes but very slowly. Not before there is lethal global warming.
So where is the cause of this headache? CO2 is the blanket but the first cause is incoming solar radiation! Under that analysis solar input management is oddly closer to the ultimate driver.
But isn't that symptom management, more like a painkiller? Yes, it appears to be.
Would drawing CO2 out of the atmosphere seem preferable to aerosol management? Seems so, yes.
Is that logical, given the causal chain? Good question! That’s why we’re in favour of doing experiments very soon to evaluate how to remove CO2 from the atmosphere but we also are ready to consider small scale experiments in aerosol management if CO2 removal by a more natural-based process doesn’t scale up sufficiently.