For context, the “huge expense” you refer to below, for the first 15 years of deployment, is about 1.5x the estimated cost of the Camp fire in California last week.
Or, 15 years of deployment (including development costs), are about 15% of the costs in the US alone from the 2017 hurricane season. And certainly far cheaper than actually solving the problem by pulling out the CO2. Lots of reasons to be concerned about SAI, but as far as costs are concerned, the appropriate concern should be that it is too cheap, and that cost won’t present enough of a barrier to deployment. (And as I’ve pointed out before, saying this doesn’t “solve” the climate problem is like pointing out that air bags don’t “solve” the problem of having car accidents, or a million other analogies. Of course it doesn’t. No-one says it does. But it could reduce impacts and prevent lots of climate damages. Until we are certain that the climate problem can be “solved” by other means, it would be premature to dismiss something that has the potential to limit damages.) From: geoengineering@googlegroups.com [mailto:geoengineering@googlegroups.com] On Behalf Of Franz Dietrich Oeste Sent: Saturday, November 24, 2018 6:49 AM To: andrew.lock...@gmail.com; geoengineering@googlegroups.com Subject: Re: [geo] Stratospheric aerosol injection tactics and costs in the first 15 years of deployment - IOPscience Thanks to Wake Smith and Gernot Wagner for their work! Their paper may open our eyes to the probable unsuitability of the climate influencing tool Stratospheric Solar Radiation Management (SRM) or as named by the authors Stratospheric Aerosol Injection (SAI): SRM shall act within the stratosphere 20 km above the ground. To gain a temperature reduction of 0.30 K in 2047 it needs a yearly uplift to this height of 1,5 million tons of sulfur. The sulfur shall be burned by new kind of aircrafts in situ to gain gaseous SO2 (boiling point -10 °C) which becomes transformed by oxidiation and hydration to about 6 million tons aerosol made of a rather concentrated sulfuric acid - per year. This aerosol shall spread around the globe and mirror parts of the sun radiation back into the space. With the existing aircraft design sulfur lifting to these heights is impossible. A new kind of aircraft needs to be developed to do the job. This new aircraft should be able to lift a payload of 25 tons of liquid sulfur to 20 km above the ground then keeping at this height and burn there the sulfur load which emits with the flue gas as SO2. About 60 000 flights per year are necessary to gain the global temperature reduction of 0,30 K. Thankfully this article discusses very clearly within chapter 6 that such activities could not remain undetected. Their conclusion is that it would be rather impossible that those activities remain undetected or might kept as a secret. According to this low result of 0,30 K global temperature decrease gained by this huge expense and 1,5 Million tons of sulfur burned in the stratosphere the SRM method seems completely unsuitable to solve our climate problem. Not only that the SRM method does not reduce any of the increasing levels of the essential greenhouse gases CO2 and methane, it surely increases the CO2 gas level. Any reduction of the sun radiation at the surface decrease the assimilation by which plants transform CO2 into organic C and oxygen. Further SRM would increase the methane level by decreasing the UV radiation dependent hydroxyl radical level which acts as a degradation tool to methane and further volatile organics because the sun radiation decrease by SRM concerns particularly the UV fraction. It is my very hope that this article helps to reduce the hype about SRM. Franz D. Oeste ------ Originalnachricht ------ Von: "Andrew Lockley" <andrew.lock...@gmail.com<mailto:andrew.lock...@gmail.com>> An: geoengineering@googlegroups.com<mailto:geoengineering@googlegroups.com> Gesendet: 23.11.2018 16:36:27 Betreff: [geo] Stratospheric aerosol injection tactics and costs in the first 15 years of deployment - IOPscience http://iopscience.iop.org/article/10.1088/1748-9326/aae98d/meta Stratospheric aerosol injection tactics and costs in the first 15 years of deployment Wake Smith1 and Gernot Wagner2 Published 23 November 2018 • © 2018 The Author(s). Published by IOP Publishing Ltd Environmental Research Letters, Volume 13, Number 12 Download Article PDF DownloadArticle ePub Article has an altmetric score of 157 Abstract We review the capabilities and costs of various lofting methods intended to deliver sulfates into the lower stratosphere. We lay out a future solar geoengineering deployment scenario of halving the increase in anthropogenic radiative forcing beginning 15 years hence, by deploying material to altitudes as high as ~20 km. After surveying an exhaustive list of potential deployment techniques, we settle upon an aircraft-based delivery system. Unlike the one prior comprehensive study on the topic (McClellan et al 2012 Environ. Res. Lett. 7 034019), we conclude that no existing aircraft design—even with extensive modifications—can reasonably fulfill this mission. However, we also conclude that developing a new, purpose-built high-altitude tanker with substantial payload capabilities would neither be technologically difficult nor prohibitively expensive. We calculate early-year costs of ~$1500 ton−1 of material deployed, resulting in average costs of ~$2.25 billion yr−1 over the first 15 years of deployment. We further calculate the number of flights at ~4000 in year one, linearly increasing by ~4000 yr−1. We conclude by arguing that, while cheap, such an aircraft-based program would unlikely be a secret, given the need for thousands of flights annually by airliner-sized aircraft operating from an international array of bases. -- 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<mailto:geoengineering+unsubscr...@googlegroups.com>. To post to this group, send email to geoengineering@googlegroups.com<mailto:geoengineering@googlegroups.com>. Visit this group at https://groups.google.com/group/geoengineering. For more options, visit https://groups.google.com/d/optout. -- 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<mailto:geoengineering+unsubscr...@googlegroups.com>. To post to this group, send email to geoengineering@googlegroups.com<mailto:geoengineering@googlegroups.com>. Visit this group at https://groups.google.com/group/geoengineering. For more options, visit https://groups.google.com/d/optout. -- 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 post to this group, send email to geoengineering@googlegroups.com. Visit this group at https://groups.google.com/group/geoengineering. For more options, visit https://groups.google.com/d/optout.
