Andrew, In the case of CDR like DAC, one can immediately know much carbon is extracted and pricing is easy. In the case of carbon stocks increase due to SRM, attribution of the stock increase to SRM would be almost an impossible task in the real world.
Bala On Wed, Apr 29, 2020 at 9:07 PM Andrew Lockley <andrew.lock...@gmail.com> wrote: > I would recommend that you consider the numbers on this, before forming a > firm view. To order of magnitude, 1t S delivered is $1000 (mileage may > vary). If 1Mt a year is roughly enough to offset the RF of global warming, > then about 10pc of that is a CO2 effect. That's about 0.1 millionth of > global warming per t of S, on an annual basis - according to your figures. > Assuming we sustain the intervention for a century, that's $100k for > maintenance of that 1t, for a century - again offsetting 0.1 millionth. > > Offsets go for about $3/t > https://www.energysage.com/other-clean-options/carbon-offsets/costs-and-benefits-carbon-offsets/ > > There's about 1Tt of CO2 to offset - ie $3T, using the offset price. 0.1 > millionths of that is $300k > > So your $100k costs gives you a $300k return. > > Not bad, unless (as usual) I've fluffed my 4th grade math. > > Andrew > > On Wed, 29 Apr 2020, 15:44 Govindasamy Bala, <bala....@gmail.com> wrote: > >> With so much uncertainty surrounding this small indirect carbon cycle >> effects of SRM, I would not bother about monetizing calculations at >> this time. >> Bala >> >> On Wed, Apr 29, 2020 at 5:49 PM Andrew Lockley <andrew.lock...@gmail.com> >> wrote: >> >>> That is indeed correct, but there is no accepted approach to >>> financialise temporary radiative forcing. The effect on the carbon cycle >>> would give a way to create a business model for SRM operations - as >>> described in the papers I've sent. >>> >>> Andrew >>> >>> On Wed, 29 Apr 2020, 12:32 Govindasamy Bala, <bala....@gmail.com> wrote: >>> >>>> Andrew, >>>> Technically, carbon and radiative forcing are equivalent to each other. >>>> There are standard formulas to go from carbon to radiative forcing. >>>> Bala >>>> >>>> On Wed, Apr 29, 2020 at 4:45 PM Andrew Lockley < >>>> andrew.lock...@gmail.com> wrote: >>>> >>>>> The reason that the CDR aspect is significant is that there is already >>>>> a way to monetise this, through voluntary carbon offsets. This was first >>>>> suggested by Sargoni and I >>>>> https://www.researchgate.net/publication/284534197_Environment_Policy_Solar_Radiation_Management_and_the_voluntary_carbon_market >>>>> >>>>> There's no such scheme available to monetise radiative forcing >>>>> >>>>> Andrew >>>>> >>>>> On Wed, 29 Apr 2020, 11:43 Govindasamy Bala, <bala....@gmail.com> >>>>> wrote: >>>>> >>>>>> Andrew, >>>>>> >>>>>> "Are you saying that SRM effect on the carbon cycle still appears to >>>>>> be the net removal of Atmospheric CO2?" >>>>>> >>>>>> Yes, that is what the models say since this first 2008 PNAS paper by >>>>>> Matthews and Ken on this topic which showed that CO2 levels would be >>>>>> lower >>>>>> in SRM scenarios. This work finds that CO2 is reduced from 900 ppm to >>>>>> about >>>>>> 800 ppm in the atmosphere by 2100 in the A2 scenario. Not a lot as CO2 >>>>>> forcing goes up only logarithmically with CO2 concentration >>>>>> >>>>>> https://www.pnas.org/content/104/24/9949 >>>>>> >>>>>> There would be of course large uncertainties but I think the >>>>>> qualitative result would not change across models. I would not go that >>>>>> far >>>>>> to say it is a CDR technique. I would rather say it is a secondary >>>>>> benefit >>>>>> or a co-benefit. >>>>>> >>>>>> Bala >>>>>> >>>>>> On Wed, Apr 29, 2020 at 1:42 PM Andrew Lockley < >>>>>> andrew.lock...@gmail.com> wrote: >>>>>> >>>>>>> So, to confirm: >>>>>>> Are you saying that SRM effect on the carbon cycle still appears to >>>>>>> be the net removal of Atmospheric CO2? >>>>>>> >>>>>>> If so, SRM can legitimately be used as a CDR technique. It may >>>>>>> therefore be eligible for Carbon credits, as per this paper. >>>>>>> https://journals.sagepub.com/doi/abs/10.1177/1461452916630082 >>>>>>> >>>>>>> On Wed, 29 Apr 2020, 08:56 Govindasamy Bala, <bala....@gmail.com> >>>>>>> wrote: >>>>>>> >>>>>>>> Andrew, >>>>>>>> >>>>>>>> You are absolutely right that "In situations where plants don't >>>>>>>> remain to decomposition (agro forestry), there will be a loss of NPP" >>>>>>>> >>>>>>>> Stock changes between two time periods are basically the integral >>>>>>>> of the net fluxes between the two time periods. In a warming scenario, >>>>>>>> there is net outward flux (and stocks decline) because the integrated >>>>>>>> respiratory fluxes more than the integrated in flux of NPP. In SRM >>>>>>>> scenario, integrated net flux is positive because the integrated >>>>>>>> respiratory fluxes are smaller than integrated in flux. >>>>>>>> >>>>>>>> Best, >>>>>>>> Bala >>>>>>>> >>>>>>>> On Wed, Apr 29, 2020 at 12:30 PM Andrew Lockley < >>>>>>>> andrew.lock...@gmail.com> wrote: >>>>>>>> >>>>>>>>> If the incoming flux decreases, the stock will reduce. To counter >>>>>>>>> this, the outgoing flux must decrease by as much, or more. What is >>>>>>>>> this >>>>>>>>> corresponding decrease in the outward flux? >>>>>>>>> >>>>>>>>> Is it that decomposition of leaf litter, etc. is slowed by cooler >>>>>>>>> and drier conditions? >>>>>>>>> >>>>>>>>> In situations where plants don't remain to decomposition (agro >>>>>>>>> forestry), what will be the effect? Your results imply a loss of NPP. >>>>>>>>> >>>>>>>>> Andrew >>>>>>>>> >>>>>>>>> On Wed, 29 Apr 2020, 07:11 Govindasamy Bala, <bala....@gmail.com> >>>>>>>>> wrote: >>>>>>>>> >>>>>>>>>> Andrew, >>>>>>>>>> >>>>>>>>>> This is no contradiction between the Keith et al's commentary and >>>>>>>>>> this paper. Keith et al.'s paper is about stocks and this JGR paper >>>>>>>>>> is >>>>>>>>>> about the rate of flow of carbon between the atmosphere and the land >>>>>>>>>> biosphere (flux). The stocks and fluxes can behave very differently. >>>>>>>>>> The >>>>>>>>>> cooling caused by SRM reduces the rate of fluxing of carbon between >>>>>>>>>> the >>>>>>>>>> atmosphere and plants but overall it helps to build the carbon >>>>>>>>>> stocks in >>>>>>>>>> biomass and soils and hence reduce the atmospheric CO2. >>>>>>>>>> >>>>>>>>>> Another good example for stocks and fluxes behaving very >>>>>>>>>> differently is the change in precipitation (flux) and atmospheric >>>>>>>>>> water >>>>>>>>>> vapor (stock) under global warming. It is well established now that >>>>>>>>>> precipitation increases at the rate of 2-3% per deg warming while >>>>>>>>>> water >>>>>>>>>> vapor increases at the rate of about 7% per deg warming. >>>>>>>>>> >>>>>>>>>> Best, >>>>>>>>>> Bala >>>>>>>>>> >>>>>>>>>> On Wed, Apr 29, 2020 at 10:18 AM Andrew Lockley < >>>>>>>>>> andrew.lock...@gmail.com> wrote: >>>>>>>>>> >>>>>>>>>>> Poster's note: this has the opposite sign to other work on the >>>>>>>>>>> subject eg >>>>>>>>>>> https://keith.seas.harvard.edu/publications/solar-geoengineering-reduces-atmospheric-carbon-burden >>>>>>>>>>> >>>>>>>>>>> >>>>>>>>>>> https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1029/2019JD031883 >>>>>>>>>>> >>>>>>>>>>> Journal of Geophysical Research: AtmospheresVolume 125, Issue 9 >>>>>>>>>>> Research Article >>>>>>>>>>> A Model‐Based Investigation of Terrestrial Plant Carbon Uptake >>>>>>>>>>> Response to Four Radiation Modification Approaches >>>>>>>>>>> Lei Duan Long Cao Govindasamy Bala Ken Caldeira >>>>>>>>>>> First published:04 April 2020 >>>>>>>>>>> https://doi.org/10.1029/2019JD031883 >>>>>>>>>>> >>>>>>>>>>> Abstract >>>>>>>>>>> A number of radiation modification approaches have been proposed >>>>>>>>>>> to counteract anthropogenic warming by intentionally altering >>>>>>>>>>> Earth's >>>>>>>>>>> shortwave or longwave fluxes. While several previous studies have >>>>>>>>>>> examined >>>>>>>>>>> the climate effect of different radiation modification approaches, >>>>>>>>>>> only a >>>>>>>>>>> few have investigated the carbon cycle response. Our study examines >>>>>>>>>>> the >>>>>>>>>>> response of plant carbon uptake to four radiation modification >>>>>>>>>>> approaches >>>>>>>>>>> that are used to offset the global mean warming caused by a >>>>>>>>>>> doubling of >>>>>>>>>>> atmospheric CO2. Using the National Center for Atmospheric Research >>>>>>>>>>> Community Earth System Model, we performed simulations that >>>>>>>>>>> represent four >>>>>>>>>>> idealized radiation modification options: solar constant reduction, >>>>>>>>>>> sulfate >>>>>>>>>>> aerosol increase (SAI), marine cloud brightening, and cirrus cloud >>>>>>>>>>> thinning >>>>>>>>>>> (CCT). Relative to the high CO2 state, all these approaches reduce >>>>>>>>>>> gross >>>>>>>>>>> primary production (GPP) and net primary production (NPP). In high >>>>>>>>>>> latitudes, decrease in GPP is mainly due to the reduced plant >>>>>>>>>>> growing >>>>>>>>>>> season length, and in low latitudes, decrease in GPP is mainly >>>>>>>>>>> caused by >>>>>>>>>>> the enhanced nitrogen limitation due to surface cooling. The >>>>>>>>>>> simulated GPP >>>>>>>>>>> for sunlit leaves decreases for all approaches. Decrease in sunlit >>>>>>>>>>> GPP is >>>>>>>>>>> the largest for SAI which substantially decreases direct sunlight, >>>>>>>>>>> and the >>>>>>>>>>> smallest for CCT, which increases direct sunlight that reaches the >>>>>>>>>>> land >>>>>>>>>>> surface. GPP for shaded leaves increases in SAI associated with a >>>>>>>>>>> substantial increase in surface diffuse sunlight, and decreases in >>>>>>>>>>> all >>>>>>>>>>> other cases. The combined effects of CO2 increase and radiation >>>>>>>>>>> modification result in increases in primary production, indicating >>>>>>>>>>> the >>>>>>>>>>> dominant role of the CO2 fertilization effect on plant carbon >>>>>>>>>>> uptake. >>>>>>>>>>> >>>>>>>>>>> Plain Language Summary >>>>>>>>>>> A number of radiation modification approaches have been proposed >>>>>>>>>>> to intentionally alter Earth's radiation balance to counteract >>>>>>>>>>> anthropogenic warming. However, only a few studies have analyzed the >>>>>>>>>>> potential impact of these approaches on the terrestrial plant >>>>>>>>>>> carbon cycle. >>>>>>>>>>> Here, we simulate four idealized radiation modification approaches, >>>>>>>>>>> which >>>>>>>>>>> include direct reduction of incoming solar radiation, increase in >>>>>>>>>>> stratospheric sulfate aerosols concentration, enhancement of marine >>>>>>>>>>> low >>>>>>>>>>> cloud albedo, and decrease in high‐level cirrus cloud cover, and >>>>>>>>>>> analyze >>>>>>>>>>> changes in plant photosynthesis and respiration. The first three >>>>>>>>>>> approaches >>>>>>>>>>> cool the earth by reducing incoming solar radiation, and the last >>>>>>>>>>> approach >>>>>>>>>>> allows more outgoing thermal radiation. These approaches are >>>>>>>>>>> designed to >>>>>>>>>>> offset the global mean warming caused by doubled atmospheric CO2. >>>>>>>>>>> Compared >>>>>>>>>>> to the high CO2 world, all approaches will limit plant growth due to >>>>>>>>>>> induced surface cooling in high latitudes and will lead to reduced >>>>>>>>>>> nitrogen >>>>>>>>>>> supply in low latitudes, leading to an overall reduction in the >>>>>>>>>>> plant >>>>>>>>>>> carbon uptake over land. Different approaches also produce different >>>>>>>>>>> changes in surface direct and diffuse sunlight, which has important >>>>>>>>>>> implications for plant photosynthesis. Relative to the unperturbed >>>>>>>>>>> climate, >>>>>>>>>>> the combined effects of enhanced CO2 and radiation modifications >>>>>>>>>>> leads to >>>>>>>>>>> an increase in plants' primary production. >>>>>>>>>>> >>>>>>>>>>> -- >>>>>>>>>>> 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/CAJ3C-04U16sw-Z9QCLEVXqs5Z0r0MRzGN0dfr-A8%2By_eaaYiag%40mail.gmail.com >>>>>>>>>>> <https://groups.google.com/d/msgid/geoengineering/CAJ3C-04U16sw-Z9QCLEVXqs5Z0r0MRzGN0dfr-A8%2By_eaaYiag%40mail.gmail.com?utm_medium=email&utm_source=footer> >>>>>>>>>>> . >>>>>>>>>>> >>>>>>>>>> >>>>>>>>>> >>>>>>>>>> -- >>>>>>>>>> With Best Wishes, >>>>>>>>>> >>>>>>>>>> >>>>>>>>>> ------------------------------------------------------------------- >>>>>>>>>> G. Bala >>>>>>>>>> Professor >>>>>>>>>> Center for Atmospheric and Oceanic Sciences >>>>>>>>>> Indian Institute of Science >>>>>>>>>> Bangalore - 560 012 >>>>>>>>>> India >>>>>>>>>> >>>>>>>>>> Tel: +91 80 2293 3428; +91 80 2293 2505 >>>>>>>>>> Fax: +91 80 2360 0865; +91 80 2293 3425 >>>>>>>>>> Email: gb...@iisc.ac.in; bala....@gmail.com >>>>>>>>>> Web:http://dccc.iisc.ac.in/dr_govindasamy_bala_profile.html >>>>>>>>>> >>>>>>>>>> ------------------------------------------------------------------- >>>>>>>>>> >>>>>>>>>> >>>>>>>> >>>>>>>> -- >>>>>>>> With Best Wishes, >>>>>>>> >>>>>>>> ------------------------------------------------------------------- >>>>>>>> G. Bala >>>>>>>> Professor >>>>>>>> Center for Atmospheric and Oceanic Sciences >>>>>>>> Indian Institute of Science >>>>>>>> Bangalore - 560 012 >>>>>>>> India >>>>>>>> >>>>>>>> Tel: +91 80 2293 3428; +91 80 2293 2505 >>>>>>>> Fax: +91 80 2360 0865; +91 80 2293 3425 >>>>>>>> Email: gb...@iisc.ac.in; bala....@gmail.com >>>>>>>> Web:http://dccc.iisc.ac.in/dr_govindasamy_bala_profile.html >>>>>>>> ------------------------------------------------------------------- >>>>>>>> >>>>>>>> >>>>>> >>>>>> -- >>>>>> With Best Wishes, >>>>>> >>>>>> ------------------------------------------------------------------- >>>>>> G. Bala >>>>>> Professor >>>>>> Center for Atmospheric and Oceanic Sciences >>>>>> Indian Institute of Science >>>>>> Bangalore - 560 012 >>>>>> India >>>>>> >>>>>> Tel: +91 80 2293 3428; +91 80 2293 2505 >>>>>> Fax: +91 80 2360 0865; +91 80 2293 3425 >>>>>> Email: gb...@iisc.ac.in; bala....@gmail.com >>>>>> Web:http://dccc.iisc.ac.in/dr_govindasamy_bala_profile.html >>>>>> ------------------------------------------------------------------- >>>>>> >>>>>> >>>> >>>> -- >>>> With Best Wishes, >>>> >>>> ------------------------------------------------------------------- >>>> G. Bala >>>> Professor >>>> Center for Atmospheric and Oceanic Sciences >>>> Indian Institute of Science >>>> Bangalore - 560 012 >>>> India >>>> >>>> Tel: +91 80 2293 3428; +91 80 2293 2505 >>>> Fax: +91 80 2360 0865; +91 80 2293 3425 >>>> Email: gb...@iisc.ac.in; bala....@gmail.com >>>> Web:http://dccc.iisc.ac.in/dr_govindasamy_bala_profile.html >>>> ------------------------------------------------------------------- >>>> >>>> >> >> -- >> With Best Wishes, >> >> ------------------------------------------------------------------- >> G. Bala >> Professor >> Center for Atmospheric and Oceanic Sciences >> Indian Institute of Science >> Bangalore - 560 012 >> India >> >> Tel: +91 80 2293 3428; +91 80 2293 2505 >> Fax: +91 80 2360 0865; +91 80 2293 3425 >> Email: gb...@iisc.ac.in; bala....@gmail.com >> Web:http://dccc.iisc.ac.in/dr_govindasamy_bala_profile.html >> ------------------------------------------------------------------- >> >> -- With Best Wishes, ------------------------------------------------------------------- G. Bala Professor Center for Atmospheric and Oceanic Sciences Indian Institute of Science Bangalore - 560 012 India Tel: +91 80 2293 3428; +91 80 2293 2505 Fax: +91 80 2360 0865; +91 80 2293 3425 Email: gb...@iisc.ac.in; bala....@gmail.com Web:http://dccc.iisc.ac.in/dr_govindasamy_bala_profile.html ------------------------------------------------------------------- -- 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/CAD7fhVm%2BZc91h1mogxZttyUztC9ASp5bKkVaNDz%3DuzpSYXY1PQ%40mail.gmail.com.
