[geo] SRM and tropical Monsoon precipitation

changes not just for SAI but for any forcing. An investigation of the relationship between tropical monsoon precipitation changes and stratospheric sulfate aerosol optical depth Anu Xavier, Govindasamy Bala, Shinto Roose, Usha KH Abstract Stratospheric aerosol geoengineering (SAG) is one of the

[geo] Safe and Just Earth System Boundaries

Not sure if this Nature paper was posted last week. https://doi.org/10.1038/s41586-023-06083-8 The metric for safe aerosol loading for the global boundary is the interhemispheric differences in AOD. The setting of this global boundary was partly inferred from several previous SAG (stratospheric a

[geo] Aerosol loading and tropical monsoon precipitation

https://link.springer.com/article/10.1007/s00382-023-06799-3 This new paper in Climate Dynamics is relevant to stratospheric sulfate aerosol geoengineering. The interhemispheric difference in forcing causes a sure signal in tropical monsoon systems. Some of you may be already well aware of this. I

Re: [geo] positive forcing in all SSPs but GMST falls ?

It is all "relative". The 1.9 Wm-2 is relative to the pre-industrial times and hence there is a warming in 2100 relative to the preindustrial time. However, in the SSP1-1.9 scenario, the forcing and warming peak somewhere around 2050, and then the forcing (and hence warming) decline slightly becau

[geo] Fwd: IUGG 2023 - Abstract Submission Deadline EXTENDED

-- Forwarded message - From: Date: Mon, Feb 13, 2023 at 8:41 PM Subject: IUGG 2023 - Abstract Submission Deadline EXTENDED To: [image: A picture containing text Description automatically generated] Dear Govindasamy Bala, This is to kindly inform you that the abstract

[geo] IUGG meeting

A gentle reminder. The abstract submission deadline for the IUGG session on SRM in Berlin is 14 Feb 2023 M07 Earth System Response to Solar Radiation Modification: Modeling, Impacts and Uncertainties*Convener(s): Govindasamy Bala (India), Hauke Schmidt (Germany)* *Co-Convener(s): Long Cao

[geo] Fwd: IUGG 2023 - Important Updates for Conveners and Co-Conveners

A gentle reminder. The abstract submission deadline for the IUGG session on SRM in Berlin is 14 Feb 2023 M07 Earth System Response to Solar Radiation Modification: Modeling, Impacts and Uncertainties*Convener(s): Govindasamy Bala (India), Hauke Schmidt (Germany)* *Co-Convener(s): Long Cao (China

[geo] Feedbacks for Solar vs CO2 forcing

This new paper from the Journal of Climate is relevant to solar geoengineering. Key take-home message: feedback strength is weaker for solar forcing than CO2 forcing. This is related to the difference in latitudinal warming patterns (solar forcing causes marginally larger warming in the tropical r

Re: [geo] Make sunsets - Calculating Cooling

limate + Engineering + Synbio* > *Inventions* <https://www.synthetic-rabbit.com>* Linkedin > <https://www.linkedin.com/in/reiss-jones-b78520174/> **Blog* > <https://reissjones.substack.com/?utm_source=substack&utm_medium=web&utm_campaign=substack_profile> > > On

Re: [geo] Make sunsets - Calculating Cooling

this is all good and well-known, but the cost of this commercial venture (as per the news) is way too high. For a 2deg offset, the calculations show ~4 TgSO2 of injection per year which translates to ~ 40 Trillion dollars per year at a rate of $10 per gram of SO2. Cost estimates have gone through

[geo] Geoengineering session @ IUGG 2023

Response to Solar Radiation Modification: Modeling, Impacts and Uncertainties*Convener(s): Govindasamy Bala (India), Hauke Schmidt (Germany)* *Co-Convener(s): Long Cao (China), Simone Tilmes (Spain), John Moore (USA), Michael MacCracken (UK)* *Description* To achieve temperature stabilization goal

Re: [geo] Re: Stratospheric warming, SRM and aerosol injection events

Besides the effects on stratospheric circulation and chemistry, stratospheric warming caused by sulfate aerosols reduces the effectiveness of what we are trying to achieve. The main intent is to increase sunlight reflection. Part of this cooling effect is offset by stratospheric warming. In a 2019

[geo] Re: [CDR] FF vs LULCC emissions

; disturbance (fire, logging, thinning) that prevent it from recovering > pre-clearing carbon stocks. > > Could you explain the rationale for assuming that all deforestation is > followed by regrowth? > > Kind regards, > > Dan > > > > On Oct 6, 2022, at 6:55 AM, Go

[geo] FF vs LULCC emissions

https://doi.org/10.1088/1748-9326/ac69fd This ERL paper demonstrating the fundamental difference between Fossil Fuel emissions and LULCC was published some months back, but I am not sure it was posted here. *Key message:* FF emissions and LULCC are fundamentally different. Hence, in terms of clim

Re: [geo] Climate model bias

I am not at all surprised by the regional bias of this magnitude in the previous generation of models. The paper says this bias is reduced in CMIP6 models to about 10 Wm-2. These biases are related to how global models "represent" cloud properties such as cloud liquid water, liquid cloud fraction,

Re: [geo] Solar geoengineering to cool the planet: Not if, but when

'Solar geoengineering is not happening yet, but there has been quite a lot of research in that direction and the technology is essentially ready to go' Is the technology really ready? Looks like we have a controversy on this notion of "technological readiness" too. On Fri, May 6, 2022 a

[geo] SG and Tropical Monsoons

Dear All, In this paper that came out last week in Climate Dynamics , we looked at the changes in mean precipitation in tropical monsoon regions for sulfate injections at different latitudes. Key message: India could experience persistent droughts if ae

Re: [geo] Actual, live, real, SAI happening right now?

SAI option involves sulfate aerosols (scattering aerosols), not black carbon aerosols or smoke which are absorbing aerosolsI believe BC aerosols in large quantities in the stratosphere would have devastating consequences for stratospheric ozone. Also, there is no ocean fertilization effect from

Re: [geo] A Model‐Based Investigation of Terrestrial Plant Carbon Uptake Response to Four Radiation Modification Approaches - Duan - 2020 - Journal of Geophysical Research: Atmospheres - Wiley Online

, > University of Edinburgh, Mayfield Road, Edinburgh EH9 3DW, Scotland > s.sal...@ed.ac.uk, Tel +44 (0)131 662 1180 WWW.homepages.ed.ac.uk/shs, > YouTube Jamie Taylor Power for Change > > On 03/05/2020 16:02, Govindasamy Bala wrote: > > Andrew, > > In the case of CDR like DA

Re: [geo] A Model‐Based Investigation of Terrestrial Plant Carbon Uptake Response to Four Radiation Modification Approaches - Duan - 2020 - Journal of Geophysical Research: Atmospheres - Wiley Online

bad, unless (as usual) I've fluffed my 4th grade math. > > Andrew > > On Wed, 29 Apr 2020, 15:44 Govindasamy Bala, wrote: > >> With so much uncertainty surrounding this small indirect carbon cycle >> effects of SRM, I would not bother about monetizing ca

Re: [geo] A Model‐Based Investigation of Terrestrial Plant Carbon Uptake Response to Four Radiation Modification Approaches - Duan - 2020 - Journal of Geophysical Research: Atmospheres - Wiley Online

tury - 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 >> milliont

Re: [geo] A Model‐Based Investigation of Terrestrial Plant Carbon Uptake Response to Four Radiation Modification Approaches - Duan - 2020 - Journal of Geophysical Research: Atmospheres - Wiley Online

porary 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, wrote: > >> Andrew, >> Technically,

Re: [geo] A Model‐Based Investigation of Terrestrial Plant Carbon Uptake Response to Four Radiation Modification Approaches - Duan - 2020 - Journal of Geophysical Research: Atmospheres - Wiley Online

tive forcing > > Andrew > > On Wed, 29 Apr 2020, 11:43 Govindasamy Bala, 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 mo

Re: [geo] A Model‐Based Investigation of Terrestrial Plant Carbon Uptake Response to Four Radiation Modification Approaches - Duan - 2020 - Journal of Geophysical Research: Atmospheres - Wiley Online

ll 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

Re: [geo] A Model‐Based Investigation of Terrestrial Plant Carbon Uptake Response to Four Radiation Modification Approaches - Duan - 2020 - Journal of Geophysical Research: Atmospheres - Wiley Online

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, wrote: > >> Andrew, >> >>

Re: [geo] A Model‐Based Investigation of Terrestrial Plant Carbon Uptake Response to Four Radiation Modification Approaches - Duan - 2020 - Journal of Geophysical Research: Atmospheres - Wiley Online

l 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/10.102

Re: [geo] IPCC Review Comments - AR6WG1 - SOD

SRM is assessed in section 4.6.3.3 CDR is assessed in section 5.6 On Mon, Mar 16, 2020 at 6:31 PM Andrew Lockley wrote: > Poster's note: IDK whether this has any SRM/CDR relevant chapters, but I'm > sure many people on these lists will want to sign up, anyway. Feedback on > likely contents woul

[geo] [paper] The Climatic Effects of Hygroscopic Growth of Sulfate Aerosols in the Stratosphere

Hi Andrews, https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1029/2019EF001326 This paper in Earth's Future (published online last week) quantifies the climatic effects of hygroscopic growth of sulfate aerosols in the stratosphere. Here, the cooling effect is more when aerosols are placed in th

Re: [geo] Climate system response to stratospheric sulfate aerosols: sensitivity to altitude of aerosol layer

Andrew Lockley wrote: > Is 26k less good than 25? > > On Tue, 17 Dec 2019, 08:37 Govindasamy Bala, wrote: > >> Andrew, >> >> Sedimentation effect works in the same direction as the effect we >> identified in our study. Therefore, higher the altitude of injection

Re: [geo] Climate system response to stratospheric sulfate aerosols: sensitivity to altitude of aerosol layer

njection altitude? > > Andrew > > On Mon, 16 Dec 2019, 10:36 Govindasamy Bala, wrote: > >> Andrew, >> Many modeling groups (e.g. Tilmes and others) have already performed >> simulations that inject aerosols at different heights and thus have >> included the se

Re: [geo] Climate system response to stratospheric sulfate aerosols: sensitivity to altitude of aerosol layer

f I understand from the email below , you used aerosols with no fall > speed. Are experiments planned to simulate aerosol descent? > > Andrew > > On Mon, 16 Dec 2019, 05:43 Govindasamy Bala, wrote: > >> Andrews, >> >> We did not do experiments with aerosols above

Re: [geo] Climate system response to stratospheric sulfate aerosols: sensitivity to altitude of aerosol layer

smaller side effects, and should be > better understood both on the modeling and implementation cost as the trade > may well be worth it. > > > > doug > > > > *From:* geoengineering@googlegroups.com *On > Behalf Of *Govindasamy Bala > *Sent:* Saturday,

Re: [geo] Climate system response to stratospheric sulfate aerosols: sensitivity to altitude of aerosol layer

Dear Andrew, Thanks for the posting. The heights studied were 16, 19 and 22 km, height that are relevant to solar radiation modification problem.. The final paragraph in the paper is worth reading to get more quantitative information from this modeling study. "To summarize, for the same mass, the

[geo] Sensitivity of the surface climate to the height of the stratospheric sulfate layer

Dear All, This work is now published in Earth System Dynamics as a discussion paper. When we started this work, we had hard time understanding the sensitivity to the height of the sulfate aerosol layer. In the paper, we explain the sensitivity in terms of the effective radiative forcing. https:/

[geo] Geoengineering: Should India Tread Carefully or Go Full Steam Ahead?

https://thewire.in/the-sciences/geoengineering-should-india-tread-carefully-or-go-full-steam-ahead Geoengineering: Should India Tread Carefully or Go Full Steam Ahead? Solar geoengineering doesn’t help reduce carbon emissions, and is founded on reckoning with the distressing possibility that redu

[geo] Nature Letter - India forges ahead with solar-geoengineering studies

Dear All, This brief correspondence appears in this weeks Nature Correspondence: India forges ahead with solar-geoengineering studies Govindasamy Bala and Akhilesh Gupta India has been contributing to the evaluation, discussion and implementation of solar-geoengineering research for almost a

[geo] Geoengineering and temperature extremes

Dear all, This paper (freely downloadable) from my group investigates the effect of solar geoengineering on temperature extremes on global and regional scales using idealized simulations. This is part 2 of the 2-part study. http://www.currentscience.ac.in/Volumes/114/05/1036.pdf *Regional sc

[geo] Geoengineering and Precipitation Extremes

Dear All, This paper (freely downloadable) from my group investigates the effect of solar geoengineering on precipitation on global and regional scales using idealized simulations. This is part 1 of a 2-part study. http://www.currentscience.ac.in/Volumes/114/05/1024.pdf *Regional scale analysis

[geo] Methane Efficacy

important component of climate change discussions as Methane is one of the most important short-lived climate forcers. Does shortwave absorption by methane influence its effectiveness? - Angshuman Modak - Govindasamy Bala - Ken Caldeira - Long Cao Abstract In this study, using

[geo] Arctic Geoengineering and Tropical Rainfall

as it is a open access article *Effects of Arctic geoengineering on precipitation in the tropical monsoon regionsAditya Nalam · Govindasamy Bala · Angshuman Modak* *Abstract* Arctic geoengineering wherein sunlight absorption is reduced only in the Arctic has been suggested as a remedial

[geo] Deforestation and Precipitation changes in Monsoonal regions

the atmosphere. http://www.pnas.org/content/early/2015/02/23/1423439112.abstract *Effects of large-scale deforestation on precipitation inthe monsoon regions: Remote versus local effects* N. Devaraju1, Govindasamy Bala, and Angshuman Modak Divecha Center for Climate Change & Center

[geo] ACP paper: Assessing the effects of varying the meridional distribution of aerosols in SRM

This following paper is published in ACP today. The main focus is on the hydrological impacts of varying the latitudinal distribution of a FIXED amount of aerosols. Sensitivity of simulated climate to latitudinal distribution of solar insolation reduction in solar radiation management A. Modak and

Re: [geo] Re: paper showing that "turning down the sun" experiments have similar climate results to "prescribed stratospheric aerosol" experiments

;> On Friday, July 25, 2014 11:39:52 AM UTC-4, kcaldeira wrote: >>> >>>> Folks, >>>> >>>> Andrew wrote something the other day about "turning down the sun" >>>> experiments NOT being a good analogue for stratospheric aerosol >>&

Re: [geo] Plan to avert global warming by cooling planet artificially 'could cause climate chaos' - The Independent

Dear All, The last sentence in the abstract is misleading: "This effect is not captured when geoengineering is modelled as a reduction in total solar irradiance, suggesting caution is required when interpreting model results from solar dimming experiments as analogues for stratospheric aerosol geo

Re: [geo] Fwd: Hiatus in global mean T trends

ted at Bala's request. > > A > -- Forwarded message -- > From: "Govindasamy Bala" > Date: Sep 28, 2013 7:23 AM > Subject: Hiatus in global mean T trends > To: "Andrew Lockley" > Cc: > > Hi Andrew, > > I have a brief discu

[geo] Sensitivity of simulated climate to latitudinal distribution of solar insolation reduction in SRM geoengineering methods

Here is A discussion Paper on geoengineering in Atmospheric Chemistry and Physics that came out today Sensitivity of simulated climate to latitudinal distribution of solar insolation reduction in SRM geoengineering methods A. Modak and G. Bala Divecha Centre for Climate Change & Centre for Atmosp

Re: [geo] tropospheric aerosol use

"Climate changes" by Budyko, on page 244, discusses why tropospheric aerosols are not as effective as stratospheric aerosols for climate modification. 1) life time is only a couple of weeks 2) Particle size becomes too big quickly and hence not effective for scattering 3) Presence of clouds make th

Re: [geo] Charitable donations for geoengineering research

I (Indian Institute of Science) would be happy to receive funds to do research in geoengineering science (modeling). Bala On Fri, Jan 13, 2012 at 5:00 AM, Andrew Lockley wrote: > It would be useful, as a matter of record, to have on this list any > institutions which currently accept donations sp

[geo]

Anyone has a copy of this report? Can I get a pdf? Aines, R. and Friedmann, J., 2008. Enabling Cost Effective CO2 Capture Directly From the Atmosphere, Lawrence Livermore National Laboratory, Livermore, CA, USA Thanks, -- Best wishes, --

Re: [geo] Wind and wave energies are not renewable after all

Hi David, Couple of questions. Generation of wind energy would increase the KE dissipation rate but this is not an external forcing to the climate system. I agree there would be local and regional climate changes but there should be no global mean warming. Right? The current KE dissipation rate i

[geo] Re: monsoons

If I recall going through papers that used IPCC multi-model simulations, the * mean* Indian Monsoon rainfall is projected to increase between 5 and 25 % by year 2100. I do not recall the results on intraseasonal and interannual variability though... Bala On Mon, Sep 7, 2009 at 5:17 PM, Peter Read

[geo] Re: runaway climate change

Page # 71 of the book "Global warming: Understanding the forecast" by David Archer has a nice description on runaway feedback. BTW, I guess there is no such thing as runaway climate change B On Mon, Feb 2, 2009 at 5:55 PM, Andrew Lockley wrote: > > I have been unable to find any citations in

[geo] Re: runaway climate change

Runaway feedback means running its course completely. It is feedback specific. A good example is the presumed water vapor feedback on Venus. Apparently, earth and venus started with similar amount of h2o. Because Venus started with much higher surface temperature, the evolution of temperature and