Good post, especially on how this could play in the public. I don't know if the public might not be convinced that the risks of geoengineering are too high, though. Playing the Dr. Strangelove card might work. Especially as some of the proponents fit the profile. And the audience isn't merely your average elderly Ohio couple, but also the countries that are committed to reducing CO2.
We have to keep this in its original context. Geoengineering is a last resort, and can only be used transitionally, in the case of catastrophic, runaway climate change (warming at and above the 5 degrees celcius range). Like lobbing a nuke at an incoming meteorite. It can't replace reducing CO2 emissions.
We also need to prioritise. Planting trees and mechanical air capture of carbon are better than injecting SO2 into the stratosphere, which again is better than seeding the oceans with iron dust. In my opinion...
The problem we will see lies partly with the political discourse on climate change. It is now all about combatting CO2, whereas it needs to be about shifting to a sustainable economy.
That's my thoughts to a T.
It also fits into situation (1) in this comment, and avoids the trap of situation (2). Words and ideas I offer here may be used freely and without attribution.
And why do you think so? Obviously, you can't foresee all effects of either option (neither can I), so how can you rank them? (Certainly not by price, iirc fertilizing the oceans would be cheaper. It's not iron dust, btw, but a ferric salt.)
Planting trees...
Oh, how cute. It just doesn't help. To capture CO2, you must also be willing to cut them down and cover them with enough dirt to prevent them from rotting.
Planting trees... Oh, how cute. It just doesn't help. To capture CO2, you must also be willing to cut them down and cover them with enough dirt to prevent them from rotting.
I did say that all geoengineering options are transitional. Planting trees on the scale of, like, half the Sahara will have a big effect (and might have some questionable ecological consequences).
On seeding the seas: I think that algae have a very important role in the self-regulation of our planet that we don't fully understand yet. For that reason, I think that tinkering with algae on a large scale is more dangerous than an option that has a natural experiment as a precedent which indicates that it will not have catastrophic side-effects. Otherwise, I think that it might lead to mass extinctions among other sea life through eutrophication.
Iron dust is definitely considered, see here and here, and here.
Obviously, you can't foresee all effects of either option (neither can I), so how can you rank them?
Being able to see all the effects (of anything) is too high a standard. Ranking options and choosing actions always goes forward with imperfect predictions and best judgement.
From what I can see, the iron approach isn't very attractive, but I'm glad that it was taken seriously enough to be investigated through open-sea experiments. Words and ideas I offer here may be used freely and without attribution.
