Cross posting to geo as this is a fascinating concept and I was unaware of. I have questions 1) do climate models typically include a) PSC formation b) strat/trop water exchange 2) SAI causes sulphuric acid particles to rain out eventually, along with any water they've absorbed hygroscopically. Does SAI therefore reduce the likelihood of PSC formation?
A On Sun, 25 Dec 2022, 06:23 Michael Hayes, <electrogeoc...@gmail.com> wrote: > "The present decade may be the last opportunity to develop the knowledge, > technical capability, and political will for the actions that are needed to > save global coastal regions from long-term inundation.” > > HOW NOT TO INCREASE THE RATE OF SEA LEVEL RISE: > > Using SAI will, without a doubt, warm the polar regions as sulfur creates > heat trapping polar stratospheric clouds. Relying upon SAI to contribute to > stopping or even slowing down sea level rise is not a reliable plan on the > face it. Those two dots do not connect. > > Moreover, increased CH4 emissions, as we are now seeing, will also > increase PSCs. If the affects on the polar regions from of SAI and > increased CH4 emissions are combined, polar ice loss will likely go into > overdrive. Past abundance of PSCs likely triggered an equitable atmosphere > and, in turn, an AMOC collapse along with massive polar ice loss. > > https://groups.seas.harvard.edu/climate/eli/research/equable/psc.html > > Furthermore, grossly eroding the polar 03 layer, an expected byproduct of > SAI deployment, over the most biologically productive regions of our ocean > would clearly drive many marine species into a rapid extenction spiral and > reduce primary production on a global scale. There are a number of other > serious biogeochemical and socio-political concerns with SAI as many know. > > Marine Cloud Brightening, on the other hand, does not carry these risks > and MCB can be started today with few biogeochemical risk factors and few > international policy risk factors. Most importantly, the deployment of SAI > has the greatest risk of igniting a war of any mitigation option due to the > trans-border nature of SAI. Again, MCB carries no such extream, if not > existential, risk factors. > > This entire field of climate disruption mitigation is centered upon the > concept of risk reduction, deployment of the one mitigation option that > clearly has, by far, the maximum risk factors seems to be counter to the > end goal of global risk reduction especially in view of the SRM MCB option > that carries no such risks. SAI is not fundamentally needed for SRM as MCB > is availablr, SAI will more than likely be highly distructive to the > environment on many levels as well as short-term and likely long-term > international relations. Why go there? > > Hanson et al. make no attempt to justify the call for SAI over MCB. Why? > > On Sat, Dec 24, 2022, 1:03 PM Robert Chris <robertgch...@gmail.com> wrote: > >> I'm not sure why Hansen et al would use the word 'geoengineering' in this >> way. It was clearly defined as a response to climate change more than a >> decade ago by The Royal Society, David Keith and others, and an essential >> part of that definition was that the intervention in the climate system was >> *deliberate >> *and *intended to ameliorate *the effects of climate change. The word >> should probably now be allowed to Rest in Peace as the discourse has moved >> on and it has been superseded. >> >> My own thoughts on this paper are below. In brief, it is much like the >> curate's egg - good in parts. >> >> Comments on *Global warming in the pipeline* (Hansen et al 2022) >> >> The core message is that both the magnitude and response times of human >> causes of climate change and responses to it have been seriously >> misrepresented by the scientific community. This has been due largely >> to inadequacy in the manner in which climate models have handled >> uncertainties relating to both the warming effect of a doubling of >> atmospheric greenhouse gases, and the impact of human generated aerosols. >> They argue that making ‘much of the planet inhospitable for humanity and >> [causing] the loss of coastal cities to sea level rise … can still be >> avoided via a reasoned policy response’. They prescribe three policies: >> a) a universal escalating carbon price; b) rapid and deep emissions >> reductions supported by greenhouse gas removal from the atmosphere, and the >> possible short-term deployment of albedo enhancement (increasing the amount >> of sunlight reflected back to outer space); and c) effective global >> cooperation. >> >> The bulk of this lengthy paper is devoted to a detailed analysis of the >> history of model-derived estimates of the warming effect of a doubling of >> atmospheric greenhouse gases, technically referred to as the Equilibrium >> Climate Sensitivity (ECS) and the cooling effect of aerosols (pollution >> associated with the burning of fossil fuels). They consider ECS to be >> closer to 5oC than the generally accepted 3oC. They further explain >> their preferred metric of Earth System Sensitivity (ESS) that includes a >> wider range of climate factors than ECS and therefore more accurately >> reflects the likely warming impact of increased atmospheric greenhouse >> gases (GHGs). They assess ESS to be about 10oC before accounting for >> aerosols. >> >> The lack of reliable data about aerosols, both historical and current, >> and considerable uncertainty about their complex interactions with clouds, >> are, they explain, the reason that their climatic effect has been >> underestimated in climate models. From a variety of sources, they >> estimate that aerosol cooling might reduce GHG warming by about 3oC, >> producing a net latent warming of about 7oC. >> >> The climatic effect of these revised values is much greater warming >> locked in from historical emissions than previously anticipated. They >> estimate that by 2050 surface temperature will have increased by 2oC and >> the remainder of the 10oC would occur within a century assuming current >> levels of emissions are maintained and the aerosols continue to be reduced >> and are largely eliminated as part of global public health programmes. >> >> The paper repeatedly refers to lack of data and uncertainties about >> various climatic effects and response times and makes a number of >> suggestions for further research. However, notwithstanding these >> shortcomings, the authors provide a cogent argument to support their claim >> that as these knowledge gaps succumb to scientific progress, the extent and >> rate of climate change will be shown to have been grossly underestimated. >> >> For all the erudition evident in their analysis of climate change, their >> policy prescription seems disturbingly confused, and perhaps even naïve. >> The first two policy proposals are climate focussed, seeking to reduce >> the atmospheric burden of GHGs by reducing emissions and removal of already >> emitted GHGs still resident in the atmosphere, and to the extent that these >> don’t reduce surface temperature fast enough, consideration of albedo >> enhancement (AE). They do not explore the different cooling dynamics of >> reducing atmospheric GHGs and AE but do use five short sentences to >> highlight the risks associated with AE without any assessment of the risks >> of not undertaking AE. The implication is that although reducing >> atmospheric GHGs may not be sufficient to avert the climate disasters they >> refer to, AE should only be deployed if it has an acceptable risk profile. >> The possibility, even the likelihood, that the risks associated with AE >> might be considerably less than the risks of not deploying it, is not >> considered. This is not a balanced approach to risk analysis. >> >> Their third policy, that the nations of the world collaborate effectively >> to reduce emissions, must be seen in the context of more than three decades >> of international negotiations under the aegis of the UNFCCC. This >> policy prescription appears to be a case of hope triumphing over experience. >> If experience is taken as a more secure guide for future action, it seems >> unlikely that there will be a radical realignment of geopolitical forces on >> a timescale short enough to enable the political collaboration necessary to >> deliver the practical and climatically effective deployments at scale >> envisaged by these authors. >> >> The rapid climate change now underway may have been accelerated by human >> behaviour but it has its own momentum that does not respect the political >> machinations of humans. The time has long passed when we needed more >> science, more research, more understanding, to know that climate change >> poses an existential threat, and that the necessary response was at least >> to stop exacerbating the situation by allowing our emissions to grow >> unconstrained. While these authors have done a great service in >> highlighting shortcomings in our earlier understanding about the scale and >> imminence of a climate catastrophe, the policy prescriptions remain the >> same as they were in 1990 and before, namely, to change our behaviour so as >> to eliminate the earth’s energy imbalance (EEI). This task has become >> more challenging, more costly and considerably more risky as a result of >> three decades of relative inaction. While the policy rhetoric may be >> more compelling today, its practical realisation remains as elusive as ever. >> The unanswered question is whether that can change soon enough. That’s >> a political rather than scientific question. My personal view, for what >> it's worth, is that we are probably at or close to the point where the >> risks of effective action overwhelm the political appetite for taking them. >> >> Robert Chris >> >> >> On 24/12/2022 17:56, Mike Biddle wrote: >> >> Great framing Dan. You beat me to the punch and with a much better >> reply. >> >> Best regards, >> >> >> Dr. Mike Biddle >> >> Partner | Evok Innovations >> >> San Francisco Bay Area Office >> >> c: 925-393-9129 <+19253939129> >> >> e: m...@evokinnovations.com >> >> >> >> Sign up *here* <http://eepurl.com/cAkAsj> to get the latest news from >> Evok Innovations! >> >> ------------------------------ >> *From:* carbondioxideremo...@googlegroups.com >> <carbondioxideremo...@googlegroups.com> >> <carbondioxideremo...@googlegroups.com> on behalf of Dan Miller >> <d...@rodagroup.com> <d...@rodagroup.com> >> *Sent:* Saturday, December 24, 2022 12:19:37 AM >> *To:* Greg Rau <gh...@sbcglobal.net> <gh...@sbcglobal.net> >> *Cc:* Clive Elsworth <cl...@endorphinsoftware.co.uk> >> <cl...@endorphinsoftware.co.uk>; carbondioxideremo...@googlegroups.com >> <carbondioxideremo...@googlegroups.com> >> <carbondioxideremo...@googlegroups.com>; Jim Hansen >> <jimehan...@gmail.com> <jimehan...@gmail.com> >> *Subject:* Re: [CDR] James Hansen's Recent Paper: Global Warming in the >> Pipeline >> >> Jim is reframing the term “Geoengineering.” Geoengineering is currently >> thought of the intentional interference on the climate to counter global >> warming. But global warming itself is massive geoengineering on its own and >> will have devastating consequences. When viewed this way, CDR & SRM are >> used to *counter* the geoenginnering we have done and are doing to the >> Earth. >> >> People today worry that SRM will have negative consequences — as if >> emitting 2.4 trillion tons of CO2 into the atmosphere doesn’t??? SRM is >> child’s play compared to what we are doing and we will soon reach “points >> of no return.” >> >> I like to compare SRM to cancer treatment. If a doctor told you they >> would irradiate you with dangerous rays and inject you with poison, you >> would think they were crazy and you would refuse. But if she explains that >> you will die without the treatment, then those “dangerous” treatments seem >> a lot more palatable. It’s the cancer that is the main problem, not the >> treatment. >> >> Dan >> >> >> >> On Dec 23, 2022, at 9:35 PM, Greg Rau <gh...@sbcglobal.net> >> <gh...@sbcglobal.net> wrote: >> >> *“"human-made geoengineering of Earth’s climate must be rapidly phased >> out,” *i.e., we must stop emitting greenhouse gases, remove CO2 from >> the atmosphere, and research and implement safe solar radiation management >> to counter the massive geoengineering experiment we are currently running” >> >> I’m confused, rapidly phase out bad geoengineering (emissions), rapidly >> phase in good geoengineering (CDR, SRM)? Geoengineering: Villain and/or >> savior? >> Greg >> >> Sent from my iPhone >> >> On Dec 21, 2022, at 7:52 PM, Clive Elsworth >> <cl...@endorphinsoftware.co.uk> <cl...@endorphinsoftware.co.uk> wrote: >> >> >> Excellent summary, thanks Dan. >> >> Clive >> >> On 22/12/2022 02:04 GMT Dan Miller <d...@rodagroup.com> >> <d...@rodagroup.com> wrote: >> >> >> James Hansen and 14 co-authors recently released a preprint (not yet peer >> reviewed) paper titled *“Global Warming in the Pipeline.”* >> >> This is an important paper that makes a number of key points, but the >> bottom line is we must act immediately to address the climate crisis. >> Hansen uses the framing *"human-made geoengineering of Earth’s climate >> must be rapidly phased out” *to call for emissions elimination, CDR and >> SRM. >> >> Hansen Newsletter Summary: >> https://mailchi.mp/caa/global-warming-in-the-pipeline?e=a29768a646 >> >> Full paper PDF: >> https://arxiv.org/pdf/2212.04474.pdf >> >> Here is a summary of some of the key points of this quite long (48 page) >> paper: >> >> 1. The Earth Climate Sensitivity (ECS) — the Earth’s *short-term* >> response to a CO2 doubling — is higher than previously assumed. Most >> scientists said it was ~3ºC, but Hansen et al now say it is 4ºC or more >> based on paleoclimate data. *This means there is more warming “in the >> pipeline” than previously assumed.* >> >> 2. While humans have increased atmospheric CO2 by 50% since the >> industrial revolution, the actual climate forcing from *all* the added >> greenhouse gases is now ~4W/m^2, which* is equivalent to a doubling of >> CO2* (i.e., CO2e (including all greenhouse gases, not just CO2) is about >> 560 ppm). >> >> 3. Part of the current warming has been hidden by human-made >> particulate air pollution (aerosols), mainly sulfur. When North America and >> Europe started to reduce emissions after the introduction of clean air acts >> in the 1970's, regional and global warming became more pronounced. In the >> past decades China and global shipping slashed sulfur emissions through >> cleaner fuels and sulfur filter systems ('scrubbers'). There are clear >> signals from ground, ocean and satellite based observations that *the >> rate of global warming has recently doubled*, which needs to be taken >> into account in risk assessments. >> >> 4. *Assuming* today’s forcing (4 W/m^2) stabilizes and human-made >> aerosols are eliminated, when all feedbacks — including “long-term” >> feedbacks — play out, *we are on track for about 10ºC warming and 6~7ºC >> if aerosols stay at today’s levels*. This is a “scenario” and we still >> control our future, though we are on track to *increase* climate forcing >> from today’s 4 W/m^2. >> >> 5. If greenhouse gas forcings keeps growing at the current rate, it >> could *match the level** PETM mass extinction >> <https://en.wikipedia.org/wiki/Paleocene%E2%80%93Eocene_Thermal_Maximum> >> within >> a century*. We are increasing climate forcing 20X faster than in the >> PETM so “long-term” feedbacks won’t take as long as in the paleo record >> (though some feedbacks will still be much longer than a human lifetime). >> >> 6. The paper concludes that we must: (a) implement a carbon fee and >> border duty (Fee and Dividend); (b) *"human-made geoengineering of >> Earth’s climate must be rapidly phased out,” *i.e., we must stop >> emitting greenhouse gases, remove CO2 from the atmosphere, and research and >> implement safe solar radiation management to counter the massive >> geoengineering experiment we are currently running; and (c) we must improve >> international cooperation to allow the developing world to grow using clean >> energy. >> >> 7. A companion paper will be coming out that addresses the* near-term >> shutdown of the AMOC and associated “multi-meter” sea level rise on a >> century timescale*. >> >> I did a Clubhouse podcast on this paper that you can listen to in your >> browser. Leon Simons, a co-author of the paper, was my guest. It’s a long >> podcast (2.5 hours)! >> >> <MKVLW5Wx.png> >> >> Hansen: We Are Committed to 7ºC Warming! - Climate Chat >> <https://www.clubhouse.com/room/MKVLW5Wx?utm_medium=ch_room_xerc&utm_campaign=JXq0RHi9uzX4m75doji2uw-507541> >> clubhouse.com >> <https://www.clubhouse.com/room/MKVLW5Wx?utm_medium=ch_room_xerc&utm_campaign=JXq0RHi9uzX4m75doji2uw-507541> >> >> Let me know if you have any questions. >> >> Best, >> Dan >> >> -- >> 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 carbondioxideremoval+unsubscr...@googlegroups.com. >> To view this discussion on the web visit >> https://groups.google.com/d/msgid/CarbonDioxideRemoval/1A78A029-7B12-4975-89B3-98C8E249A423%40rodagroup.com >> <https://groups.google.com/d/msgid/CarbonDioxideRemoval/1A78A029-7B12-4975-89B3-98C8E249A423%40rodagroup.com?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 carbondioxideremoval+unsubscr...@googlegroups.com. >> To view this discussion on the web visit >> https://groups.google.com/d/msgid/CarbonDioxideRemoval/1269668398.179416.1671681157537%40email.ionos.co.uk >> <https://groups.google.com/d/msgid/CarbonDioxideRemoval/1269668398.179416.1671681157537%40email.ionos.co.uk?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 carbondioxideremoval+unsubscr...@googlegroups.com. >> To view this discussion on the web visit >> https://groups.google.com/d/msgid/CarbonDioxideRemoval/61E92492-BF86-47E8-A570-3FB76B51B0E9%40rodagroup.com >> <https://groups.google.com/d/msgid/CarbonDioxideRemoval/61E92492-BF86-47E8-A570-3FB76B51B0E9%40rodagroup.com?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 carbondioxideremoval+unsubscr...@googlegroups.com. >> To view this discussion on the web visit >> https://groups.google.com/d/msgid/CarbonDioxideRemoval/BY3PR18MB4754B70A8582602228FFCB32D6EE9%40BY3PR18MB4754.namprd18.prod.outlook.com >> <https://groups.google.com/d/msgid/CarbonDioxideRemoval/BY3PR18MB4754B70A8582602228FFCB32D6EE9%40BY3PR18MB4754.namprd18.prod.outlook.com?utm_medium=email&utm_source=footer> >> . >> >> Regards >> >> Robert >> >> -- >> 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 carbondioxideremoval+unsubscr...@googlegroups.com. >> To view this discussion on the web visit >> https://groups.google.com/d/msgid/CarbonDioxideRemoval/65a6acf3-1d77-5a15-8f1c-6953e34d9119%40gmail.com >> <https://groups.google.com/d/msgid/CarbonDioxideRemoval/65a6acf3-1d77-5a15-8f1c-6953e34d9119%40gmail.com?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 carbondioxideremoval+unsubscr...@googlegroups.com. > To view this discussion on the web visit > https://groups.google.com/d/msgid/CarbonDioxideRemoval/CABjtO1dZcFXvBEqfjpvw16%2BiPnUuJLoOY0OQK4FfDss9x5iDig%40mail.gmail.com > <https://groups.google.com/d/msgid/CarbonDioxideRemoval/CABjtO1dZcFXvBEqfjpvw16%2BiPnUuJLoOY0OQK4FfDss9x5iDig%40mail.gmail.com?utm_medium=email&utm_source=footer> > . > -- You received this message because you are subscribed to the Google Groups "geoengineering" group. 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