This article by James Temple provides a professional overview of efforts to commercialise Iron Salt Aerosol (ISA).
https://www.technologyreview.com/2023/02/15/1068495/these-startups-hope-to-spray-iron-particles-above-the-ocean-to-fight-climate-change/ It discusses cooling effects of ISA including methane removal, ocean iron fertilization and marine cloud brightening. The article comments that a marine cloud brightening effect “would muddy the line between greenhouse-gas removal and the more controversial field of solar geoengineering.” My view is that taking this as a criticism shows the incoherence in popular understanding of climate science. If marine cloud brightening could be a fast, safe, cheap and effective way to mitigate dangerous warming, field research of ISA could be a great way to test this. Solar geoengineering is no more controversial than ocean iron fertilization, given that both are under a de facto ban on field research. The article comments that “if it brightened marine clouds, it would likely draw greater scrutiny given the sensitivity around geoengineering approaches that aim to achieve cooling by reflecting away sunlight.” It may prove to be the case that ISA could only be deployed by an intergovernmental planetary cooling agreement of the scale of the Bretton Woods Agreement of 1944 to establish the IMF and World Bank. In that governance scenario, the scrutiny placed on all cooling technologies will be intense regardless of the balance of effects between brightening and greenhouse gas removal. I disagree with the scientists quoted in the article who oppose field tests. That is a dangerous and complacent attitude, failing to give due weight to the risks of sudden tipping points that can only be prevented by albedo enhancement and GHG removal at scale. Learning by doing is the most safe and effective strategy. If there are unexpected effects it is easy to stop the trials. The only risk of well governed field tests is that they would provide information to justify a slower transition from fossil fuels. On balance that is not a serious risk, given that emissions are expected to continue regardless of climate concerns. Cooling technologies are essential to balance the ongoing heating, the sooner the better. I was pleased that the article included my comment that our company decided not to pursue our ISA field test proposal because the overall political governance framework is not ready to support this form of geoengineering. This illustrates that strategic discussion of ethics and governance will need to be far more advanced before any geoengineering deployment is possible. I explored these moral themes in a recent discussion note <https://pdfhost.io/v/nn85Rgk.g_Moral_Perspectives_on_Climate_Policy> published by the Healthy Planet Action Coalition. Robert Tulip -- You received this message because you are subscribed to the Google Groups "geoengineering" group. To unsubscribe from this group and stop receiving emails from it, send an email to geoengineering+unsubscr...@googlegroups.com. To view this discussion on the web visit https://groups.google.com/d/msgid/geoengineering/2bc901d942cd%248ee19e60%24aca4db20%24%40rtulip.net.