RE: [geo] SRM offset standards?
Tim – the difference between the 0.22% and 2% is (i) factor of 4 from ratio of projected area to surface area of a sphere, (ii) factor of 1/0.7 to account for the existing albedo of the Earth, (iii) factor of 3/3.7 since 2% is a rough estimate for 2xCO2, and (iv) efficacy of response to solar vs CO2 is not one (that is, the same radiative forcing doesn’t give the same warming for different mechanisms, see Hansen et al 2015). From: geoengineering@googlegroups.com On Behalf Of Tim Sippel Sent: Monday, May 4, 2020 4:08 AM To: geoengineering Subject: Re: [geo] SRM offset standards? Thanks for the feedback. It was great to learn about a planned December 2020 publication of ISO 14082, which is being drafted as a standard for radiative forcing accounting. Now I am also aware of Andrew's 2016 'License to chill' paper (1). Methane reductions qualify for carbon offsets, despite the fact that the methane breaks down in the atmosphere over about a decade. So if the lifetime of a solar sail can be 20 years (not uncommon for many satellites), maybe it will be reasonable to qualify for some form of SRM offset standard. It should be easier to make funding decisions once the benefits are quantified in a standard. GeoShade is focused on a 1km radius design that deploys to sub-L1. A key metric is g/m^2, which determines the craft's solar acceleration. L1 is 1.5M km from earth. A new location farther sunward from L1 (maybe 2.4M km) will be an equilibrium position that accounts for the sail's solar acceleration. Using its sail, active stationkeeping is possible without any fuel-based thrust. The GeoShade design doesn't rely on any exotic technologies. It uses existing materials that are manufactured terrestrially. It doesn't rely on capturing an asteroid for building materials. The goal is to be able to manufacture and deploy in a relatively short amount of time. So it is very different from a 2006 proposal by Roger Angel (2). A 1km radius disk at sub-L1 can cancel the radiative forcing of about 10M tons of CO2 emissions (based on calculations I mentioned previously). I can't imagine trying to cancel out ALL anthropogenic RF with mirrors. To cancel today's 3W of RF requires 3/1367 W/m^2 = 0.2% of earth's sunlight (although elsewhere I see a value of 2.0% being used). The intent would be to supplement the primary ongoing efforts to replace fossil fuel energy with renewable energy sources. These sun shades are to help buy time since we are not progressing as quickly as needed to achieve the IPCC 1.5C target. The cost for the GeoShade design is estimated to be about $10/ton equivalent. (Based on IPCC 2018 2.8.4, it seems sufficient to assume a linear relationship rather than logrithmic.) My impression is that $10/ton is 10X to 100X the cost of other SRM options. (Pointers to better estimates would be appreciated.) Hopefully the cost remains low enough to be affordable as a temporary offset. Could a space-based solution be used to lead the way in achieving approval for SRM offsets? Once in position, sun shades look like a small sunspot. Hopefully something people can easily wrap their heads around. The RF benefits may be easier to quantify, track, and control compared to other SRM methods. The solar reduction is guaranteed to be small and uniform amount across the globe. It can be quickly stoped by turning the sails sideways. As long as RF reductions are a small fraction of RF increases due to greenhouse gas emissions, concerns about unintendended consequences should be minimal. For those interested in more details, the GeoShade design is based on a reflective film with a 3.9 g/m^2 density plus a 1X mass overhead for the structure and controls. A 1km radius disk produces a thrust of about 20N, resulting in a solar acceleration of about 1mm/s^2. Attitude control at sub-L1 involves very slow adjustments of the center of mass vs. the center of pressure. This is accomplished by adjusting the position of a mass, or by tilting a subset of sail panels. The more difficult problem to solve was more dramatic attitude changes that are required to support orbit raising from its start at a high LEO (enabling a significant reduction in cost). It will take about 1 year to sail to sub-L1. (1) Licence to chill: Building a legitimate authorisation process for commercial SRM operations, 2016, Andrew Lockley. https://journals.sagepub.com/doi/10.1177/1461452916630082 (2) Feasibility of cooling the Earth with a cloud of small spacecraft near the inner Lagrange point (L1), 2006, Roger Angel, Univ of Arizona. http://www.pnas.org/content/pnas/103/46/17184.full.pdf Reference Textbooks: Space Sailing, 1992, Wright Solar Sailing, 2004, McInnes Solar Sails, 2008, Vulpetti, Johnson, Matloff Advances in Solar Sailing, 2014, Editor: Macdonald -- You received this message because you are subscribed to the Google Groups "geoengineering" group. To
Re: [geo] SRM offset standards?
Thanks for the feedback. It was great to learn about a planned December 2020 publication of ISO 14082, which is being drafted as a standard for radiative forcing accounting. Now I am also aware of Andrew's 2016 'License to chill' paper (1). Methane reductions qualify for carbon offsets, despite the fact that the methane breaks down in the atmosphere over about a decade. So if the lifetime of a solar sail can be 20 years (not uncommon for many satellites), maybe it will be reasonable to qualify for some form of SRM offset standard. It should be easier to make funding decisions once the benefits are quantified in a standard. GeoShade is focused on a 1km radius design that deploys to sub-L1. A key metric is g/m^2, which determines the craft's solar acceleration. L1 is 1.5M km from earth. A new location farther sunward from L1 (maybe 2.4M km) will be an equilibrium position that accounts for the sail's solar acceleration. Using its sail, active stationkeeping is possible without any fuel-based thrust. The GeoShade design doesn't rely on any exotic technologies. It uses existing materials that are manufactured terrestrially. It doesn't rely on capturing an asteroid for building materials. The goal is to be able to manufacture and deploy in a relatively short amount of time. So it is very different from a 2006 proposal by Roger Angel (2). A 1km radius disk at sub-L1 can cancel the radiative forcing of about 10M tons of CO2 emissions (based on calculations I mentioned previously). I can't imagine trying to cancel out ALL anthropogenic RF with mirrors. To cancel today's 3W of RF requires 3/1367 W/m^2 = 0.2% of earth's sunlight (although elsewhere I see a value of 2.0% being used). The intent would be to supplement the primary ongoing efforts to replace fossil fuel energy with renewable energy sources. These sun shades are to help buy time since we are not progressing as quickly as needed to achieve the IPCC 1.5C target. The cost for the GeoShade design is estimated to be about $10/ton equivalent. (Based on IPCC 2018 2.8.4, it seems sufficient to assume a linear relationship rather than logrithmic.) My impression is that $10/ton is 10X to 100X the cost of other SRM options. (Pointers to better estimates would be appreciated.) Hopefully the cost remains low enough to be affordable as a temporary offset. Could a space-based solution be used to lead the way in achieving approval for SRM offsets? Once in position, sun shades look like a small sunspot. Hopefully something people can easily wrap their heads around. The RF benefits may be easier to quantify, track, and control compared to other SRM methods. The solar reduction is guaranteed to be small and uniform amount across the globe. It can be quickly stoped by turning the sails sideways. As long as RF reductions are a small fraction of RF increases due to greenhouse gas emissions, concerns about unintendended consequences should be minimal. For those interested in more details, the GeoShade design is based on a reflective film with a 3.9 g/m^2 density plus a 1X mass overhead for the structure and controls. A 1km radius disk produces a thrust of about 20N, resulting in a solar acceleration of about 1mm/s^2. Attitude control at sub-L1 involves very slow adjustments of the center of mass vs. the center of pressure. This is accomplished by adjusting the position of a mass, or by tilting a subset of sail panels. The more difficult problem to solve was more dramatic attitude changes that are required to support orbit raising from its start at a high LEO (enabling a significant reduction in cost). It will take about 1 year to sail to sub-L1. (1) Licence to chill: Building a legitimate authorisation process for commercial SRM operations, 2016, Andrew Lockley. https://journals.sagepub.com/doi/10.1177/1461452916630082 (2) Feasibility of cooling the Earth with a cloud of small spacecraft near the inner Lagrange point (L1), 2006, Roger Angel, Univ of Arizona. http://www.pnas.org/content/pnas/103/46/17184.full.pdf Reference Textbooks: Space Sailing, 1992, Wright Solar Sailing, 2004, McInnes Solar Sails, 2008, Vulpetti, Johnson, Matloff Advances in Solar Sailing, 2014, Editor: Macdonald -- 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/c2923c28-a830-4728-afa3-e25048112513%40googlegroups.com.
[geo] Newsletter of Week 19 of 2020
Title: Climate Engineering Newsletter Climate Engineering Newsletter for Week 19 of 2020 04.-08.05.2020, Online conference: EGU2020: Sharing Geoscience Online (#shareEGU20), online 06.05.2020, CCIS 2020 Webinar Series: IAMs, Mitigation, and Scenario development for combined intervention strategies, online 06.05.2020, Webinar: Engineering the Carbon Economy Seminar Series: Holly Buck, UCLA - Can scaling up negative emissions be compatible with social and environmental justice? (LLNL), online 07.05.2020, Webinar: Carbon 180: Leading with Soil: How climate mitigation can unlock economic opportunity for farmers, online 13.05.2020, Conference: AirMiners 2020: Foundations for a Carbon Negative Future, online 20.05.2020, Pre-ACT webinar #5: CO2 storage case studies, online 27.05.2020, CCIS 2020 Webinar Series: Solar Radiation Management, online 10.06.2020, CCIS 2020 Webinar Series: Carbon Dioxide Removal, online 08.07.2020, CCIS 2020 Webinar Series: Observations, Lab and Field Studies, online 06. 08.2020, CCIS 2020 Webinar Series: Impacts for Climate Intervention Strategies, online 06.-09.10.2020, Conference: Climate Engineering in Context 2020, Berlin / Germany 21.-23. 10.2020, Workshop: Ecological Impacts of Solar Radiation Management, Port Jefferson, New York / USA 28.-30.10. 2020, Workshop: Community Climate Intervention Strategies, Boulder, CO / USA 02.-05.11.2020, Conference: 3rd Conference of the Arabian Journal of Geosciences (CAJG), Sousse / Tunisia 06.-13.12.2020, IEA Greenhouse Gas R Programme 2020 Summer School, Bandung / Indonesia 15.-18.03.2021, Conference: GHGT-15, Abu Dhabi / United Arab Emirates 18.-21.05.2021, Conference: 2nd International Conference on Negative CO2 Emissions, Gothenburg / Sweden 04.08.2020, Call for Applications: PICS Opportunity Projects Program - 2020 Zero-Emission Vehicles Project 04.08.2020, Call for Applications: PICS Opportunity Projects Program - 2020 Competition 10.05.2020, Job: NORCE Chief scientists (no deadline), Job: Ph.D. Research Assistantship in climate and agricultural modeling in the Atmospheric Science Graduate Program at Rutgers University (no deadline), Job: ClearPath: Policy Analyst (Carbon Capture & Removal) (no deadline), Job: Postdoctoral Fellow Position – Global Warming in polar regions in ultra-high-resolution earth system model simulations Gertler, Charles G.; et al. 2020: “Weakening of the Extratropical Storm Tracks in Solar Geoengineering Scenarios.” Markusson, Nils; et al. 2020: “Social Science Sequestered.” Duan, Lei; et al. 2020: “A Model‐Based Investigation of Terrestrial Plant Carbon Uptake Response to Four Radiation Modification Approaches.” Talati, Shuchi; et al. 2020: “Once a Fringe Idea, Geoengineering Moves to Center Stage in Policy Arena.” Carbon 180: Leading With Soil Report National Energy Technology Laboratory. 2020: "Safe Geologic Storage of Captured Carbon Dioxide – DOE’s Carbon Storage R Program: Two Decades in Review." Friedmann, S.J.; et al. 2020: “Capturing Investment: Policy Design to Finance CCUS Projects in the U.S. Power Sector.” ICRLP. 2020: “Explainer: Carbon Removal.” Project: Strategy CCUS Project: C4U (Advanced Carbon Capture for steel industries integrated in CCUS Clusters) Phys.org: New self-forming membrane to protect our environment Legal Planet: Negative Emissions: The Next Bright Shiny Object in Greenhouse-Gas Emissions Reductions Clean Air Task Force: Do it right – the IRS shows why it pays to comply with storage standards Clean Air Task Force: The Status of Carbon Capture Projects in the U.S. (And What They Need to Break Ground) Institution of Mechanical Engineers: Carbon capture and storage must be widely deployed to meet emission targets Energy.gov: U.S. Department of Energy Announces $131 Million for CCUS Technologies Strategy CCUS: Partner profile: ‘Industrial symbiosis’ will open up promising regions to CCUS The Chemical Engineer: Japanese consortium to study CCU Blog post: CSAG: Lebogang Matlakala: Is Solar Radiation Management a practical solution? SRMGI: Interview with Dr. Izidine Pinto Mining.com: Mining technologies could capture ‘billions of tonnes of CO2 per year,’ says UBC prof Bloomberg: The Best Way to Slow Global Warming? You Decide in This Climate Simulator Ethanol Producer Magazine: DOE funds CCUS project at ethanol plant, opens new CCUS FOA Video: Carnegie Council for Ethics in International Affairs: Prospects for Global Coordination in an Age of Pandemics and Emerging Climate Technologies Video: ICRLP Explainer Webinar: Direct Air Capture ICRLP: Carbon Removal Glossary To unsubscribe please send short message to i...@climate-engineering.eu or use the web interface (under "user login"). In case something is missing in the newsletter, send us an email. -- You received this message because you are subscribed to the Google Groups "geoengineering" group. To unsubscribe from this group and stop receiving emails from
