Andrew
Iron Salt Aerosol adds iron chloride to the air, and has significant cloud brightening potential as a form of solar geoengineering. ISA differs from iron sulfate, which you mentioned, which is proposed as only an ocean fertilisation method for CDR and fisheries enhancement, and is not deployed as an aerosol. It is interesting that the MIT article implied the cloud brightening effect of ISA could be a negative in view of public hostility toward solar geoengineering, regardless of benefits and safety. Once we are allowed to do field tests, data will emerge on the balance of brightening and GGR effects of ISA. Before that it is premature to assume one or the other is more important. I note your comments are presented “as moderator of the Google group”. New readers may be unaware (as I understand it) that you are moderator of the geoengineering group, not the CDR group. Robert Tulip From: [email protected] <[email protected]> On Behalf Of Andrew Lockley Sent: Monday, 20 February 2023 8:05 AM Cc: [email protected] <[email protected]> <[email protected]>; geoengineering <[email protected]> Subject: Re: [CDR] Re: [HCA-list] Iron Salt Aerosol: Article in MIT Technology Review As moderator of the Google group I am just responding to the the points earlier stating that iron sulfate aerosol is not suitable for the CDR list. My personal view is that greenhouse gas removal fits very closely with CDR, to the point that they are are essentially interchangeable terms. Iron salt aerosol, where it is used to destroy methane seems to be a more appropriate fit for the CDR list than the geoengineering Google group. unless there's a lot of pushback I prefer to keep ISA in CDR and not geoengineering Andrew On Sun, 19 Feb 2023, 10:16 Clive Elsworth, <[email protected] <mailto:[email protected]> > wrote: Hi Ye I am not aware of any new data on iron salt aerosol. However, TIO2 provides little or no ocean fertilisation, which an iron containing aerosol does, albeit very diffusely if dispersed as intended. A TIO2 -based aerosol is more suitable for use near icefields, where iron may colour the surface of the ice and fertilise growth of sessile life such as biofilms and moss that would likely accelerate the melting rate during summer months. Clive On 18/02/2023 23:17 GMT Ye Tao <[email protected] <mailto:[email protected]> > wrote: Hi Clive and Peter, Have there been new data to substantiate the claims of effectiveness and scalability? I believe that previous discussion threads on ISA that I have witnessed and engaged in (based on papers cited in the ISA field and beyond) were consistent with a lack of laboratory experimental evidence to support effectiveness and scalability of this otherwise tantalizing concept. Clive, if I remember well, you wrote in the past that you did not believe ISA was optimal and were rather looking into another thing based on TiO2. Now you are again supporting ISA, I take it that new data and evidence must have emerged to rekindle your enthusiasm. If new data or concept for in situ characterization have emerged, please share preliminary results. Or perhaps Peter has performed new experiments from the list I suggested to the core group on ISA? and things look promising? Looking forward to learning more, Ye On 2/18/2023 1:29 PM, Clive Elsworth wrote: Michael We calculate that potentially tens of Gt of CO2 per year could be safely removed by iron salt aerosol dispersal over remote iron poor ocean areas at low cost, if allowed. Of course this would need to be incrementally scaled, with lots of measurement, analysis. Clive On 18/02/2023 18:11 GMT Michael Hayes <mailto:[email protected]> <[email protected]> wrote: Clive, I'm aware of the chemistry, yet this is a CDR list not a CH4 mitigation list. Removing CO2 has little involvement with CH4 mitigation. Use of iron salt is not a CDR method, and it has little if any relation to CDR policy or economics. The many CCed groups often welcome any comment on any subject under the Sun. This list, however, is focused on removing CO2, not second or third order indirect subjects that can be tacked onto CO2 removal. Getting things done requires maintaining focus, and the GE list along with many others like it simply can not maintain focus and thus are of little use and even less importance. Converting this list to a CC of the GE list is not needed, yet there seems to be a core group interested in either taking the moderators' post to do so or simply overrunning the CDR list with non CDR posts and making the CDR list a defacto non focused GE list. I object to the petty politics and to the non CDR posts. Best regards On Sat, Feb 18, 2023, 7:59 AM Clive Elsworth <[email protected] <mailto:[email protected]> > wrote: Michael Iron salt aerosol relates indirectly to CDR. Reduced warming from reduced atmospheric methane would slow the temperature rise of the ocean surface, curbing the accelerating loss of nutrient mixing owing to surface stratification. Without nutrients, less phytoplankton are available to raise ocean surface pH. A higher pH at the ocean surface lowers the partial pressure of dissolved CO2, increasing the oceanic CO2 absorption rate. Where there is chlorophyll in the ocean there tend to be marine clouds also, which provide an additional cooling effect. Thus, a beneficial feedback cycle is established, or at least the opposite destructive feedback cycle is curbed. The addition of iron to the ocean surface is of course highly controversial, even if it’s by aerosol delivery adding less than 1 mg/m² per day and with natural fertilisation by desert dust doing the same thing. Huge areas of abyssal ocean are very low in iron content, so this would also enable a slightly higher phytoplankton productivity than otherwise - over vast areas. In areas where iron is not the limiting nutrient, the addition of a tiny amount more would make essentially no difference. Clive On 18/02/2023 14:45 GMT Michael Hayes <[email protected] <mailto:[email protected]> > wrote: Again, how does this relate to CDR? CH4 is not CO2. The many other groups that have been CCed in this thread are wide open to any and all chatter about any and all subjects that can pop into people's minds. This list is about Carbon Dioxide Removal. How does your comment relate to CDR? On Fri, Feb 17, 2023, 12:49 PM Peter Fiekowsky <[email protected] <mailto:[email protected]> > wrote: Robert- Good point about the scientists uniformly calling for delaying implementation, essentially indefinitely, since they don't offer any criteria for actually starting to restore safe methane levels and protect against a methane burst. Do you think this is an ethical issue? Doubling the methane oxidation rate would result, in 5 years, in methane levels cut roughly in half--bringing warming back to roughly 2002 levels. This would likely save a million lives a year lost in the severe hurricanes, floods, wildfires and droughts we have now. And if today's methane burst gets serious, it could also save a quarter, or even all of humanity from the kind of extinction event that happened last time our planet lost the Arctic sea ice. Even if it's only a 1% chance that history repeats itself (warming is now happening 10 times faster than during the previous methane burst called the PETM), statistically that's 8 billion people divided by a 1/1000 probability, or 8 million people we could save. Is it ethical for climate scientists to make the same claims that health scientists made for tobacco companies and later that oil company scientists made about climate actions--that we need undefined "more research" before acting? Should we establish a climate ethics committee to discuss this issue publicly? Peter On Fri, Feb 17, 2023 at 4:44 AM <[email protected] <mailto:[email protected]> > wrote: 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 "Healthy Climate Alliance" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected] <mailto:[email protected]> . To view this discussion on the web visit https://groups.google.com/d/msgid/healthy-climate-alliance/2bc901d942cd%248ee19e60%24aca4db20%24%40rtulip.net <https://groups.google.com/d/msgid/healthy-climate-alliance/2bc901d942cd%248ee19e60%24aca4db20%24%40rtulip.net?utm_medium=email&utm_source=footer> . -- You received this message because you are subscribed to the Google Groups "Carbon Dioxide Removal" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected] <mailto:[email protected]> . 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