I don't think seeding the oceans with iron filings was ever a very respectable idea in the first place.
Still there is biochar which seems like a credible geoengineering strategy. And I think we're going to be forced to think about geoengineering at some stage because going zero carbon may not be enough.
Look. People need to start planting trees and region-appropriate home gardens, in addition to going zero carbon, regulating toxic materials and manufacturing processes to within an inch of their lives, and so on. Carbon isn't our only problem, given aquifer spoilage and soil erosion and the bursting of the bubble of the "miracle" of petrochemical input-intensive industrial agriculture. Inasmuch as biochar was already a pre-Columbian agricultural technique and most projects employing it today seem to be rather small scale, I am wondering whether "geoengineering" is really the right word to use to describe any effort at carbon-pollution remediation through local practice up-scaled (always only where region appropriate) via education, regulation, price incentivization, and so on.
I know enough about organic gardening to know that people who want to believe in technofixes consistently and even systematically underestimate the resilience of even devastated ecosystems that are finally being cared for rather than mistreated, and I suspect that at least some talk of tipping points being crossed that force us "reluctantly" to accept the necessity of geoengineering interventions and nuclear archipelagos and so on ultimately express the failure of imagination one has come to expect of corporate-militarists more than anything else.
I disagree strongly if you are implying that seeding the oceans with iron fillings was never treated as a respectable idea by those who think such things are respectable in the first place and megaphone them endlessly and so distract us from more local and distributed and scalable strategies that are known to be effective but are less likely to be profitable for incumbents.
Although I don't know enough about every other geoengineering strategy "on offer" to suavely trot out all the dangers and limits and hyperbole occasioned by each one (as neither unfortunately do the overabundant majority of those who handwave most enthusiastically about these strategies to the cost of sense) I do know that skipping from one scam to another to another as each is exposed as hype while the more difficult work of gathering reliable data, implementing piecemeal regulation and price incentivization, better design practices, general education, facilitation of organic, local, wholesome, carbon neutral practices at the proper scale and intensity can be done but likely won't be done while greedheads are endlessly jerking off to their effort-deferring guilt-denying profit-making authority-retaining fantasies of "greening" corporate-militarism via geoengineering isn't exactly the best idea.
Actually, as I have said before, I don't rule out geoengineering interventions in principle -- even though, as with most things futurological, many of these are entirely fantastic daydreams of megascale engineering that don't really connect up at the level of data or do-ability with the urgency of environmental problems at hand nor with accomplishments of more local strategies with track records of actual successes that could be effectively scaled via regulation, education, facilitation and so on.
My whole point is that I am skeptical about geoengineering, skeptical of those who prefer such interventions over others, skeptical of the hyperbolic discourse through which they are advocated, skeptical of their occasional genuflections to "reluctance" and "skepticism" that never has any impact on their actual advocacy.
I think it is not a co-incidence that corporate-militarism would shift from a very public denialism about environmental problems directly to a very public advocacy of geoengineering solutions to environmental problems.
The continuity between these two positions of incumbents maintaining control through extractive/industrial/capital-intensive/broadcast formations possibly matters more than the discontinuity between the two of first denying and then admitting the existence and scale and seriousness of environmental problems.
This isn't to attribute any bad motives to Jose at all, by the way, since he may well be as aware and concerned about the damage done by denialist discourse and futurological technofix-hype discourse as I am here, but just wants to ensure that the widest possible range of strategies remain on the table. I would agree with that enthusiastically.
The truth is that I expect the inherent drama of geoengineering interventions together with their likely comparative profitability to incumbents will ensure that these interventions will always draw more than their share of serious attention and consideration, whether they warrant it or not, and so we needn't worry so much about their neglect as about their preferential treatment despite the scale and intensity of their impacts in ill-understood environmental systems on which we depend for our lives.