Dan Visioni
@danvisioni.bsky.social
Climate scientist studying aerosols, chemistry, radiation, climate & society from Volcanoes 🌋and Climate Intervention. Assistant Professor at Cornell EAS, from 🇮🇹proudly🏳️🌈 More at https://dan-visioni.github.io/ and https://www.wcrp-climate.org/ci-overview
Saying at this point something as false as "there does NOT seem to be one single peer-reviewed paper, or even a body of research" kind of underlies the weakness of the entire NUA framing (together with the editorial malpractice that accompanied the publication of that manifest).
November 25, 2025 at 4:20 PM
Saying at this point something as false as "there does NOT seem to be one single peer-reviewed paper, or even a body of research" kind of underlies the weakness of the entire NUA framing (together with the editorial malpractice that accompanied the publication of that manifest).
And yes, climate is a space where shady interests exist and thrive, and care gets weaponized, so mistrust is at a minimum understandable. I’m very fine with people disagreeing with me, and just draw the line at outright lying about the topic.
November 24, 2025 at 11:07 PM
And yes, climate is a space where shady interests exist and thrive, and care gets weaponized, so mistrust is at a minimum understandable. I’m very fine with people disagreeing with me, and just draw the line at outright lying about the topic.
It’s easier to assume people who disagree with you are all stupid conspiracy theorists, or to assume that people who research something you don’t like are all driven by shady interests. Truth is that most are driven by the same kind of concerns, yet express it in different kind of works/advocacy.
November 24, 2025 at 11:07 PM
It’s easier to assume people who disagree with you are all stupid conspiracy theorists, or to assume that people who research something you don’t like are all driven by shady interests. Truth is that most are driven by the same kind of concerns, yet express it in different kind of works/advocacy.
(but I also wish people didn't feel the need to constantly say "anyone doing research into SRM ultimately just wants to replace mitigation completely" when most explicitly reject that in basically everything they write. That's also unhelpful)
November 24, 2025 at 9:55 PM
(but I also wish people didn't feel the need to constantly say "anyone doing research into SRM ultimately just wants to replace mitigation completely" when most explicitly reject that in basically everything they write. That's also unhelpful)
Yeah I think that quote is pretty bad, ugh. There are clearly both out-there, conspiracy level takes about SRM from a spectrum of people like RFKjr to some environmentalists, but also legitimate thoughtful opposition about the concept from many. I don't think it helps to conflate the two at all.
November 24, 2025 at 9:55 PM
Yeah I think that quote is pretty bad, ugh. There are clearly both out-there, conspiracy level takes about SRM from a spectrum of people like RFKjr to some environmentalists, but also legitimate thoughtful opposition about the concept from many. I don't think it helps to conflate the two at all.
Makes me REALLY happy yo hear :)
November 24, 2025 at 8:31 PM
Makes me REALLY happy yo hear :)
Oh of course, on this absolutely agreed.
November 24, 2025 at 6:26 PM
Oh of course, on this absolutely agreed.
Yes, I agree on this, I mentioned it further down the thread: bsky.app/profile/danv... The burden of proof is clearly different in the two cases, from many point of views (governance/ethics).
Given same set of models, and two different forcings (GHG, and GHG+SAI with radiative balance), do you think there is a reason to believe that the latter yields to, prima facie, less reliable responses? This is =/= from saying that the burden of proof between the two is different (which I agree).
November 24, 2025 at 5:00 PM
Yes, I agree on this, I mentioned it further down the thread: bsky.app/profile/danv... The burden of proof is clearly different in the two cases, from many point of views (governance/ethics).
Thanks Ben, was a pleasure! FWIW, today's my last class in my Climate Dynamics course (because I'm leaving for the IPCC LAM meeting Saturday) and it's also the only one where we discuss SRM and its potential problems, so this is my last slide for the day...
November 24, 2025 at 4:28 PM
Thanks Ben, was a pleasure! FWIW, today's my last class in my Climate Dynamics course (because I'm leaving for the IPCC LAM meeting Saturday) and it's also the only one where we discuss SRM and its potential problems, so this is my last slide for the day...
4) ultimately, I think whatever decision is taken in the future about SAI -and I do think one way or another, decisions will be taken about it, hopefully not in a emergencial framing- we can do research now to build the knowledge base and trust to help ensure they are good decision (be it yes or no)
November 24, 2025 at 4:17 PM
4) ultimately, I think whatever decision is taken in the future about SAI -and I do think one way or another, decisions will be taken about it, hopefully not in a emergencial framing- we can do research now to build the knowledge base and trust to help ensure they are good decision (be it yes or no)
... in which, coupled with emission reduction+CDR, it could help reduce exposure/risks/suffering in the medium term, based on current modeling results.
3) I wish more climate/ecologists/other scholars engaged with SAI more to broaden the field and *point out if such findings are wrong*
3) I wish more climate/ecologists/other scholars engaged with SAI more to broaden the field and *point out if such findings are wrong*
November 24, 2025 at 4:17 PM
... in which, coupled with emission reduction+CDR, it could help reduce exposure/risks/suffering in the medium term, based on current modeling results.
3) I wish more climate/ecologists/other scholars engaged with SAI more to broaden the field and *point out if such findings are wrong*
3) I wish more climate/ecologists/other scholars engaged with SAI more to broaden the field and *point out if such findings are wrong*
But if you want an answer...
1) I don't think we should deploy, & I wrote against for-profit SAI in clear terms
2) I think it makes sense to study it, and think through what it would take to do SAI in a fair/just/responsible way. There are clear pathways in which it can be misused, and some...
1) I don't think we should deploy, & I wrote against for-profit SAI in clear terms
2) I think it makes sense to study it, and think through what it would take to do SAI in a fair/just/responsible way. There are clear pathways in which it can be misused, and some...
November 24, 2025 at 4:17 PM
But if you want an answer...
1) I don't think we should deploy, & I wrote against for-profit SAI in clear terms
2) I think it makes sense to study it, and think through what it would take to do SAI in a fair/just/responsible way. There are clear pathways in which it can be misused, and some...
1) I don't think we should deploy, & I wrote against for-profit SAI in clear terms
2) I think it makes sense to study it, and think through what it would take to do SAI in a fair/just/responsible way. There are clear pathways in which it can be misused, and some...
Sigh, I really didn't want to take the discussion there :( I don't know how to discuss this topic on the internet in a way that doesn't lead people to assume that because I'm making a specific scientific point I am saying "let's go do SAI"...
November 24, 2025 at 4:17 PM
Sigh, I really didn't want to take the discussion there :( I don't know how to discuss this topic on the internet in a way that doesn't lead people to assume that because I'm making a specific scientific point I am saying "let's go do SAI"...
Issue is always with the counterfactual. If we're asking "do we know better a world that has no imbalance because there's net-zero" then yes, of course. But if the q is "is the hydro response in a 2.5C world more/less certain than a world with 1.5C with 1C with SAI" then it's another matter.
November 24, 2025 at 3:56 PM
Issue is always with the counterfactual. If we're asking "do we know better a world that has no imbalance because there's net-zero" then yes, of course. But if the q is "is the hydro response in a 2.5C world more/less certain than a world with 1.5C with 1C with SAI" then it's another matter.
I think this is a good point. In a way, I disagree, because we have better constraint & observations for a world that is in not in radiative imbalance compared to a world with a 2W/m2+ disequilibrium, and I think this holds true even if such balance is achieved through LW matching SW w/ SAI.
November 24, 2025 at 3:56 PM
I think this is a good point. In a way, I disagree, because we have better constraint & observations for a world that is in not in radiative imbalance compared to a world with a 2W/m2+ disequilibrium, and I think this holds true even if such balance is achieved through LW matching SW w/ SAI.
Even in GLENS, considering one large ensemble in one model, variability over extremes is smaller in the GHG case: esd.copernicus.org/articles/13/... indicating even inter-model uncertainty is reduced. Again, I am earnestly curious to know if you think there's reasons to believe this is wrong.
Indices of extremes: geographic patterns of change in extremes and associated vegetation impacts under climate intervention
Abstract. Extreme weather events have been demonstrated to be increasing in frequency
and intensity across the globe and are anticipated to increase further with
projected changes in climate. Solar cl...
esd.copernicus.org
November 24, 2025 at 3:51 PM
Even in GLENS, considering one large ensemble in one model, variability over extremes is smaller in the GHG case: esd.copernicus.org/articles/13/... indicating even inter-model uncertainty is reduced. Again, I am earnestly curious to know if you think there's reasons to believe this is wrong.
Given same set of models, and two different forcings (GHG, and GHG+SAI with radiative balance), do you think there is a reason to believe that the latter yields to, prima facie, less reliable responses? This is =/= from saying that the burden of proof between the two is different (which I agree).
November 24, 2025 at 3:49 PM
Given same set of models, and two different forcings (GHG, and GHG+SAI with radiative balance), do you think there is a reason to believe that the latter yields to, prima facie, less reliable responses? This is =/= from saying that the burden of proof between the two is different (which I agree).
Same for off-equatorial: acp.copernicus.org/articles/23/...
Models respond quite consistently on ICTZ shifts and P response depending on cross-hemispheric fluxes changes.
See also the new preprint we have with new simulations: egusphere.copernicus.org/preprints/20...
Models respond quite consistently on ICTZ shifts and P response depending on cross-hemispheric fluxes changes.
See also the new preprint we have with new simulations: egusphere.copernicus.org/preprints/20...
Climate response to off-equatorial stratospheric sulfur injections in three Earth system models – Part 1: Experimental protocols and surface changes
Abstract. There is now substantial literature on climate model studies of equatorial or tropical stratospheric SO2 injections that aim to counteract the surface warming produced by rising concentratio...
acp.copernicus.org
November 24, 2025 at 3:44 PM
Same for off-equatorial: acp.copernicus.org/articles/23/...
Models respond quite consistently on ICTZ shifts and P response depending on cross-hemispheric fluxes changes.
See also the new preprint we have with new simulations: egusphere.copernicus.org/preprints/20...
Models respond quite consistently on ICTZ shifts and P response depending on cross-hemispheric fluxes changes.
See also the new preprint we have with new simulations: egusphere.copernicus.org/preprints/20...
GLENS was only one model. If you look at multi-model response (granted, we don't have more than 7 models there, but working on more for CMIP7), annual mean T and P response across models is narrower than for SSPs. acp.copernicus.org/articles/21/...
Identifying the sources of uncertainty in climate model simulations of solar radiation modification with the G6sulfur and G6solar Geoengineering Model Intercomparison Project (GeoMIP) simulations
Abstract. We present here results from the Geoengineering Model Intercomparison Project (GeoMIP) simulations for the experiments G6sulfur and G6solar for six Earth system models participating in the C...
acp.copernicus.org
November 24, 2025 at 3:42 PM
GLENS was only one model. If you look at multi-model response (granted, we don't have more than 7 models there, but working on more for CMIP7), annual mean T and P response across models is narrower than for SSPs. acp.copernicus.org/articles/21/...
And to @thirstygecko.bsky.social 's point, I think this is really a case in which the spread for volcanoes is not a good proxy, bc details of volc injection and transport over short timescales matter for the climate outcome. But given a specific AOD distribution, models converge more than under GHG.
November 24, 2025 at 3:33 PM
And to @thirstygecko.bsky.social 's point, I think this is really a case in which the spread for volcanoes is not a good proxy, bc details of volc injection and transport over short timescales matter for the climate outcome. But given a specific AOD distribution, models converge more than under GHG.
As always, not asking this as a gotcha but as an earnest question (since I'm trying to write a paper exactly on this topic at the moment). IMO there are good reasons to think that the fact that models converge more over the hydro (and others) response to stratospheric aerosols is reasonable.
November 24, 2025 at 3:26 PM
As always, not asking this as a gotcha but as an earnest question (since I'm trying to write a paper exactly on this topic at the moment). IMO there are good reasons to think that the fact that models converge more over the hydro (and others) response to stratospheric aerosols is reasonable.
Are there any reasons to think that we have less reasonable confidence in the hydrological cycle response to SAI compared to climate change? I.e. that our uncertainties measured as multi-model projections of the outcomes of a specific SAI scenario are less reliable than for a specific GHG one?
November 24, 2025 at 3:24 PM
Are there any reasons to think that we have less reasonable confidence in the hydrological cycle response to SAI compared to climate change? I.e. that our uncertainties measured as multi-model projections of the outcomes of a specific SAI scenario are less reliable than for a specific GHG one?
Yes indeed, we should work very hard to make sure such safeguards are in place. But this means not shying away from the issue at the international level, because the vacuum left by countries hoping this doesn’t derail their climate policies will be filled by this kind of players.
November 22, 2025 at 11:59 PM
Yes indeed, we should work very hard to make sure such safeguards are in place. But this means not shying away from the issue at the international level, because the vacuum left by countries hoping this doesn’t derail their climate policies will be filled by this kind of players.