How Climate Intervention can Safely and Quickly Cool the Planet_HPAC NYC Climate Week_Sep. 26, 2025

[Ron Baiman]

Dear Colleagues,

A final edited recording of the 2025 HPAC NYC Climate Week event is not up on the HPAC YouTube channel: https://youtu.be/mz2_mRqHZuw

Title: How Climate Intervention can Safely, Effectively, Quickly and inexpensively Cool the Planet 

Delay in action to limit climate pollution has allowed end of century scenarios to prematurely initiate. Earth systems have begun to degrade and once degradation begins it does not self-restore unless the warming that caused it is removed. Degradation comes with reduction and reversal of Earth systems’ emissions sequestration that has already begun, and has the capacity to dwarf humankind’s total emissions in the very near term. This means our current climate culture’s 1.5 degree C above normal warming limit is now too warm and we must restore our climate back to within the natural variation of our Earth systems’ evolution at less than 1 degree C warming above normal. We must do this before these systems become so degraded that collapses become irreversible. To accomplish this and prevent, quoting Hobbes: "solitary, poor, nasty, brutish, and short" existential futures for much of humanity, emergency implementation of The Climate Triad Approach - Cool, Reduce, Remove - is required. As the point of no return could be as soon as mid-century, we must quickly cool our planet to give us time to reduce and draw down GHGs at a large enough scale to stabilize the climate and begin to regenerate nature. This will require net-zero emissions and removing vast amounts of legacy greenhouse gases from our atmosphere and oceans. This event focuses on the highest priority near-term cooling, or “climate intervention”, aspect of The Climate Triad approach that must be accomplished in a short time or all other actions may become moot. “Climate intervention” refers to additional ways to seek to counter or counterbalance climate change induced effects and impacts that involve: (1) reflecting solar radiation or modifying long wave radiation, (2) are global or hemispheric in scope and (3) have to potential be deployed at scale within the next 20 years. Speakers: Ron Baiman, Co-Founder and Convening Coordinator, Healthy Planet Action Coalition Bill Blecker, Chair, Education Committee, Brooklyn Society for Ethical Culture Aria McKenna, Founding Member - Healthy Pl anet Action Coalition, Writer/Producer/Host - Revolution Earth & Saving Planet Us @ Global Cooling Productions Rafe Pomerance, Distinguished Senior Arctic Policy Fellow, Woodwell Climate Research Center Jake Schwartz, Campaigns Manager, Chesapeake Climate Action Network Herb Simmens, Co-Founder, Healthy Planet Action Coalition Event by: Healthy Planet Action Coalition Program: Our event will be composed of two panels of three speakers, and then a single panel of all six, all addressing the issue of why near-term climate intervention is now necessary to supplement GHG emission reduction and draw down policies. Moderator (Ron Baiman) will introduce the panels and each of the speakers in the following order. For the first panel: 1) Bill Blecker will welcome attendees to the Brooklyn Society for Ethical Culture, pass the hat,and speak about climate organizing, 2) Aria McKenna will speak about real hope for a safe climate, and 3) Herb Simmens will talk about the climate policy triad. Each speaker will speak for about 10 minutes and this will be followed by about 20 minutes of questions from the audience. After a 10 minute bathroom break, the second panel consisting of: 4) Rafe Pomerance on climate intervention and an upper limit metric to sea-level rise, 5) Ron Baiman on near-term climate cooling and 6) Jake Schwartz on federal and NGO climate intervention politics, will convene. This panel will follow a similar schedule. For the remaining time the floor will be thrown open for questions.

Thank you to the organizers/presenters, BSEC, and as always Lucinda for editing!

Best,

Ron

--

Healthy Planet Action Coalition

YouTube Channel

@HPACoalition  (Bluesky and Twitter/X)

 Addressing the Urgent Need for Direct Climate Cooling: Rationale and Options

Baiman et al. 2024. Oxford Open Climate Change

An Open Letter to the IMO Supporting Maritime Transport that Cools the Atmosphere While Preserving Air Quality Benefits. Baiman et al. 2024. Oxford Open Climate Change

[Ron Baiman]

*now up on the HPAC YouTube channel*

Sent from my iPhone

On Oct 8, 2025, at 2:44 PM, Ron Baiman <rpba...@gmail.com> wrote:



[Ron Baiman]

Presentation (accompanying Baiman talk on near-term cooling): https://docs.google.com/presentation/d/1JQHyGudqqSrqtSfFEAZRaEW-eProPE3Y/edit?usp=sharing&ouid=116465941111195452408&rtpof=true&sd=true

Sent from my iPhone

On Oct 8, 2025, at 3:55 PM, Ron Baiman <rpba...@gmail.com> wrote:

*now up on the HPAC YouTube channel*

[H simmens]

Hi Jan,

I think your comment is right on point. And as the person who suggested the title - which no one involved with the program objected to I might add - I take responsibility. 

What the title should have done was to substitute ‘the climate triad’ for climate intervention. Which I of all people should have known to suggest as I was the one who initially came up with the term climate triad some years ago. 

I think my motivation was to contrast the HPAC position with the overly cautious neutral approach to direct climate cooling that virtually every established entity in the field takes. But I clearly went too far and none of my colleagues chose to restrain me. 

Mea Culpa!

Herb

Herb Simmens
Author of A Climate Vocabulary of the Future

“A SciencePoem and an Inspiration.” Kim Stanley Robinson
@herbsimmens
HerbSimmens.com

On Oct 9, 2025, at 8:51 AM, Jan Umsonst <j.o.u...@gmail.com> wrote:



Hi all, that is exactly the framing that will pave the way to our extinction as it implies emission reductions are secondary as we can easily and cheaply cool the climate down so why bother with emission reductions?

Framing is all!

And this headline is the perfect foundation for catastrophe: "How Climate Intervention can Safely, Effectively, Quickly and inexpensively Cool the Planet" 

There is a reason why the experts on the earth system warn from solar radiation management as the risks are unknown...

All the best

Jan

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[rob...@rtulip.net]

Dear Jan,

 

Emission reduction is secondary to climate intervention when judged against near-term risk.

 

In terms of radiative forcing, new emissions add roughly 0.035 W/m² of additional heating each year, whereas planetary darkening (albedo loss) is adding around 0.2 W/m². That means albedo collapse is currently causing over five times more heating than emissions.

 

By Pareto logic, we must focus most on the factor driving 80% of the problem, while not abandoning the other 20%. To do otherwise is to base priorities on emotion and habit rather than reason and evidence.

 

This is not an argument for “why bother with emission reductions.” Long-term, emissions reduction is indispensable for restoring planetary balance. But in the short-term, emissions cuts alone cannot affect tipping points; only rapid cooling interventions can.

 

Framing the issue in this way allows us to keep both goals intact: Intervention first, for immediate planetary survival; Emission reduction next, for long-term stability.

 

Regards

 

Robert Tulip

 

From: healthy-planet-...@googlegroups.com <healthy-planet-...@googlegroups.com> On Behalf Of Jan Umsonst
Sent: Thursday, 9 October 2025 11:51 PM
To: Ron Baiman <rpba...@gmail.com>
Cc: healthy-planet-action-coalition <healthy-planet-...@googlegroups.com>; William Beckler <bi...@bsec.org>; Aria Mckenna <ar...@globalcoolingproductions.com>; Cara Fleischer <ca...@creationcommunications.com>; Herb Simmens <hsim...@gmail.com>; Jake Schwartz <ja...@chesapeakeclimate.org>; Rafe Pomerance <rafe.po...@gmail.com>; Michael MacCracken <mmac...@comcast.net>; Healthy Climate Alliance <healthy-clim...@googlegroups.com>; Planetary Restoration <planetary-...@googlegroups.com>; Lucinda Shearman <lucindas...@hotmail.com>; Bruce Melton -- Austin, Texas <bme...@earthlink.net>
Subject: Re: [HPAC] How Climate Intervention can Safely and Quickly Cool the Planet_HPAC NYC Climate Week_Sep. 26, 2025

 

Hi all, that is exactly the framing that will pave the way to our extinction as it implies emission reductions are secondary as we can easily and cheaply cool the climate down so why bother with emission reductions?

 

Framing is all!

 

And this headline is the perfect foundation for catastrophe: "How Climate Intervention can Safely, Effectively, Quickly and inexpensively Cool the Planet" 

 

There is a reason why the experts on the earth system warn from solar radiation management as the risks are unknown...

 

All the best

 

Jan

 

Ron Baiman <rpba...@gmail.com> schrieb am Mi., 8. Okt. 2025, 22:00:

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[Tom Goreau]

You can’t only consider only the short term impacts of long-term threats, you need to integrate them over their lifetimes to compare apples and oranges.

 

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[Aria Mckenna]

I believe I have made these exact same concerns quite clear many times. I also suggested a different title to the event, but did not get any response. 

In fact, perhaps this is a perfect time to reiterate some of the framing that I believe will help us immensely in making our point....

I think it's really important to work within the environmental community's current framing to help flip the narrative and expand our conversations about earth, science and how our understanding of a warming planet has changed since the paris climate Accord.

1) We need to focus on a Net-Negative strategy asap! 

(Net-neutral has been getting pushback from the environmental community as perpetuating greenwashing. 

Thinking that net-zero will save us in our current predicament is essentially wish-washing!)

- Many Climate activists have never heard that we have passed 520 ppm greenhouse gas equivalent! This is the number we need to be focusing on. Not only carbon dioxide to reinforce our message.

- if someone wants to add James Hanson's number that includes planetary darkening, indeed all the better.

2) A warming planet leads to more warming. With so many ecosystems, quickly approaching tipping points and lives being lost right now... We need a strategy that addresses ALL the causes of warming.

Human emissions, feedback loops, AND Planetary darkening 

- natural emissions are likely exceeding human emissions currently because of our warming planet. 

(Explain feedback loops) Melting permafrost and more forest fires lead to more carbon dioxide and more methane in the atmosphere... while also reducing nature's capacity to restore a safe climate. 

3) We need to restore nature's capacity to ABSORB (or DRAW-DOWN) greenhouse gases. 

- this requires us to reflect heat through planetary brightening, along with a host of nature based solutions to increase carbon sequestration while ending deforestation. 

4) The paris climate accord has failed. We need triage to get us back on track. 

Warming is escalating dangerously toward the point of no return. 

We can restore a safe climate! 

- But only with a holistic strategy based on the climate triad ... eventually restoring safe greenhouse gas levels in the atmosphere. 

All of these points are the spirit we had behind founding this organization to begin with. It feels like so much of our framing has slipped off script. But I do not feel like my voice has been heard when I have tried to make a case for this.

I really did try to focus our messaging on these issues, which I do believe will have much more traction within the climate community. 

We will have far more influence with higher ups when it comes to supporting our cause when they feel safe in our messaging to reach their constituents.

Science alone will not win this cause, because if no one hears it, nothing will be done to support it. 

I did speak with someone with a professional branding agency, the other day about helping us to get behind some unified messaging. She is going to check to see whether they would be able to offer any services for a discounted or pro Bono rate for the time being until we have enough funding.  

Right now I feel like we are a bit all over the place. But we are also elevating our ability to be seen. 

Climate activists can and should be our friend in this.If we are going to be effective. But we need to be respectful of their concerns, while validating and adding to their current framing.

I do hope that we can all get on the same page around some accessible and easier to understand language.

(Please excuse typos and talk to text! 😆 - Sacrificing email perfection to optimize productivity and health!)

Warmest Thanks For Everything You Do,
Aria McKenna
Brand: "Saving Planet Us"
🙏🥰🩵🌏💦🐋🫒🦋🙌

Writer, Producer, Climate Communicator
Global Cooling Productions
www.GlobalCoolingProductions.com

Creator
Revolution Earth
(Romantic Cli-fi Thriller - w/ a touch of Action/Adventure/Futuristic Fantasy for TV in Development)

Connect on LinkedIn: https://www.linkedin.com/in/aria-mckenna

IMDB:
https://www.imdb.com/name/nm3994260/?ref_=ext_shr

Watch My 'BECOMING THE CHANGE' Roundtable at:
https://youtube.com/watch?v=C472MxNDzZM&si=pPYMnQW0YxCPaTUH

Learn more about the 'Climate Triad', a holistic approach to Climate Restoration at Healthy Planet Action Coalition:
www.HealthyPlanetAction.org

https://www.greentv.com/aboutus
   

[Ron Baiman]

Dear Jan,

Hopefully you’ve been able to catch some

of the presentations and discussion or at least my slides. You will see that throughout we emphasized the triad. Herb’s title won out in a vote for titles among the organizers. Speaking for myself I didn’t vote for my own title suggestion as Herb’s already had a second and I liked it.  I think it actually well served the purpose of bringing out some  strong opponents to intervention whom I think greatly enhanced our discussion.  Sometimes to get your point across in a crowded field you have to sharpen it to just the essential difference! 

Best,

Ron 

Sent from my iPhone

On Oct 9, 2025, at 8:07 AM, H simmens <hsim...@gmail.com> wrote:

Hi Jan,

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[Jan Umsonst]

Hi all, that is exactly the framing that will pave the way to our extinction as it implies emission reductions are secondary as we can easily and cheaply cool the climate down so why bother with emission reductions?

Framing is all!

And this headline is the perfect foundation for catastrophe: "How Climate Intervention can Safely, Effectively, Quickly and inexpensively Cool the Planet" 

There is a reason why the experts on the earth system warn from solar radiation management as the risks are unknown...

All the best

Jan

Ron Baiman <rpba...@gmail.com> schrieb am Mi., 8. Okt. 2025, 22:00:

--

[Jake Schwartz]

Hi all, 

Just reiterating comments from Jan and Aria, from the perspective of a progressive climate advocacy group that is leading on SRM. 

As a climate intervention movement, we need to work within the broader climate movement and frame SRM as potential and something that needs to be researched. No matter how you feel, coming at this issue through the frame of "it must be done no matter what" is bad politics and will backfire. To Jan's point, emissions reduction must remain the main thing, or we lose all credibility. Mitigation and intervention should be intrinsically linked in the discourse, so that everyone knows we cannot do one without the other. 

Best,

Jake

[rob...@rtulip.net]

Dear Tom,

The question you raise — the balance between short- and long-term factors, cooling versus decarbonisation — highlights a deep tension between effectiveness and coherence. Your argument stresses coherence of policy, which is laudable, but it risks excluding major stakeholders and therefore undermining short-term effectiveness. Keynes’ reminder that “in the long run we are all dead” applies here with particular force.

This raises a fundamental question: is the main goal progressive political victory, or slowing climate change? Many people equate the two, but that link is questionable. It seems clear that solar geoengineering alone could slow climate change, while emission reduction alone could not. A pivot toward geoengineering could buy the time needed to study and scale durable carbon solutions, while also opening the door to alliances with affected industries who have both resources and influence.

If the primary goal is to reverse climate change, then the most urgent short-term task is to restore planetary reflectivity, since albedo loss is currently the dominant driver of additional heating. Yet albedo is entirely absent from the IPCC policy agenda. This omission suggests climate policy is being shaped more by politics than by science, and it raises doubts about the wisdom of aligning our advocacy too closely with the IPCC as a political movement.

In this unsatisfactory context, insisting that cooling allies must sign up in advance to a full long-term scientific agenda risks being counterproductive — especially if it excludes the industries most directly impacted by heat, who also possess the means to act. A more pragmatic stance would be to build a broad coalition around near-term cooling, through an Albedo Accord, while encouraging ongoing research into the longer-term pathway for carbon.

 

Regards

 

Robert Tulip

[Tom Goreau]

Long term cooling is just as important, and much cheaper, than short term cooling, and both are equally needed for different time scales.

 

To view this discussion visit https://groups.google.com/d/msgid/planetary-restoration/038301dc3936%2463a7c9b0%242af75d10%24%40rtulip.net.

[Tom Goreau]

You constantly frame this as “Either-Or” “only one choice” when we need both!

 

To view this discussion visit https://groups.google.com/d/msgid/planetary-restoration/BY3PR13MB49941CBB7439CD4B5C69F636DDEEA%40BY3PR13MB4994.namprd13.prod.outlook.com.

[Aria Mckenna]

Our overarching goal should emphasize safety. 

A focus only on cooling ONLY, completely disregards the many toxic side effects of our current industrial complex, while also setting us up in a combative stance against widespread current understanding. 

It is completely unnecessary and counterproductive to focus on this either or framing. Counterproductive for climate communications and counterproductive for the safety of our planet and people and animals who live on it. 

We have had this same discussion so many times, and honestly, I have grown weary of it. And yet I can guarantee you that if we ignore the very valid concerns of climate activists, we will fail to win the essential political battle for our cause. 

HPAC was expressly founded on a holistic framing that integrates the importance of cooling as part of an essential element tied to the climate triad. 

As I recall, Jon Nissen's conversations in PRAG which were expressly focused on cooling, was exactly the reason we decided to start a new organization.. to focus on the TRIAD. While cooling is an essential part of that triad, it must not stand alone. 

Our initial steering circle was very clear on this mission, it has been very disheartening to see so many conversations straying away from this very essential understanding.

(Please excuse typos and talk to text! 😆 - Sacrificing email perfection to optimize productivity and health!)

Warmest Thanks For Everything You Do,
Aria McKenna
Brand: "Saving Planet Us"
🙏🥰🩵🌏💦🐋🫒🦋🙌

Writer, Producer, Climate Communicator
Global Cooling Productions
www.GlobalCoolingProductions.com

Creator
Revolution Earth
(Romantic Cli-fi Thriller - w/ a touch of Action/Adventure/Futuristic Fantasy for TV in Development)

Connect on LinkedIn: https://www.linkedin.com/in/aria-mckenna

IMDB:
https://www.imdb.com/name/nm3994260/?ref_=ext_shr

Watch My 'BECOMING THE CHANGE' Roundtable at:
https://youtube.com/watch?v=C472MxNDzZM&si=pPYMnQW0YxCPaTUH

Learn more about the 'Climate Triad', a holistic approach to Climate Restoration at Healthy Planet Action Coalition:
www.HealthyPlanetAction.org

https://www.greentv.com/aboutus
   

On Thu, Oct 9, 2025, 1:47 PM Mark Haubner <mhau...@gmail.com> wrote:

My thought precisely, Tom, except I'm much more of an "all-and" person at this point; from billions of small efforts plus large-scale policy swathes, all hands on deck right now. 

To view this discussion visit https://groups.google.com/d/msgid/healthy-planet-action-coalition/BY3PR13MB4994DF01503428BF549CF3E2DDEEA%40BY3PR13MB4994.namprd13.prod.outlook.com.

[Tom Goreau]

Thanks! I should have said we need all sinks on all time scales simultaneously!

 

From: Mark Haubner <mhau...@gmail.com>
Date: Thursday, October 9, 2025 at 13:47
To: Tom Goreau <gor...@globalcoral.org>
Cc: rob...@rtulip.net <rob...@rtulip.net>, Jan Umsonst <j.o.u...@gmail.com>, Ron Baiman <rpba...@gmail.com>, healthy-planet-action-coalition <healthy-planet-...@googlegroups.com>, William Beckler <bi...@bsec.org>, Aria Mckenna <ar...@globalcoolingproductions.com>, Cara Fleischer <ca...@creationcommunications.com>, Herb Simmens <hsim...@gmail.com>, Jake Schwartz <ja...@chesapeakeclimate.org>, Rafe Pomerance <rafe.po...@gmail.com>, Michael MacCracken <mmac...@comcast.net>, Healthy Climate Alliance <healthy-clim...@googlegroups.com>, Planetary Restoration <planetary-...@googlegroups.com>, Lucinda Shearman <lucindas...@hotmail.com>, Bruce Melton -- Austin, Texas <bme...@earthlink.net>
Subject: Re: [prag] RE: [HPAC] How Climate Intervention can Safely and Quickly Cool the Planet_HPAC NYC Climate Week_Sep. 26, 2025

My thought precisely, Tom, except I'm much more of an "all-and" person at this point; from billions of small efforts plus large-scale policy swathes, all hands on deck right now. 

 

On Thu, Oct 9, 2025 at 12:16 Tom Goreau <gor...@globalcoral.org> wrote:

To view this discussion visit https://groups.google.com/d/msgid/healthy-planet-action-coalition/BY3PR13MB4994DF01503428BF549CF3E2DDEEA%40BY3PR13MB4994.namprd13.prod.outlook.com.

[Tom Goreau]

And that includes temperature sinks by reflection and evapotranspiration

 

 

To view this discussion visit https://groups.google.com/d/msgid/planetary-restoration/BY3PR13MB49945D2C2DB945979F2079E8DDEEA%40BY3PR13MB4994.namprd13.prod.outlook.com.

[rob...@rtulip.net]

Hi Aria,

Thank you for again setting out your forthright position. I genuinely sympathise with much of your argument. My main concern, however, is that it is not politically practical.

Why do you think Donald Trump won office campaigning on climate denial, and then proceeded to dismantle U.S. government support for climate science? It was because he—and his voters and funders—perceive arguments for systemic economic transformation as tantamount to demanding a communist revolution, a direct attack on the capitalist order. His policies were designed to put such arguments in their place, to demonstrate where real economic and political power resides, and to underline that capitalism will not tolerate what it regards as an existential assault.

If we are serious about climate progress, especially in the U.S. but also in other countries where voters back hydrocarbon expansion, then a different strategy is needed. A temporary focus on albedo restoration, rather than systemic economic transformation, offers a way forward. Such a policy can:

• achieve rapid progress where it is technically possible,
• build industrial alliances and bipartisan understanding around cooling,
• avoid the polarisation that currently paralyses all climate action.

This approach fits squarely within the HPAC climate triad. We should understand “accelerating emission reduction” not as a tribal demand for faster decarbonisation, but as a research programme into how GGR can ultimately scale beyond total emissions—within a capitalist framework, not in opposition to it.

What you describe as “a combative stance against widespread current understanding” is, in my view, essential. The decarbonisation ideology emerged from a Marxist class war critique of capitalism, and especially of its energy industries. This argument is detailed in my attached short essay, The Ideological Roots of Decarbonisation.  People of good will have been misled by the Big Lie that decarbonisation by itself is a climate policy. The decarbonisation ideology refuses to compare the relative impacts of albedo and GHGs on planetary heat, precisely because such analysis undermines their intellectual and scientific and political foundations.  Insisting that partners buy in to the whole ‘climate justice’ shebang is a recipe for failure and collapse.

It is pointless to say “do everything” when the cooling impacts of rival actions differ by many orders of magnitude. What is needed is clarity and a practical incremental policy:

place radiative forcing at the centre of climate strategy, and focus first on building support to restore planetary reflectivity.

 

Regards

 

Robert Tulip

 

From: planetary-...@googlegroups.com <planetary-...@googlegroups.com> On Behalf Of Aria Mckenna

Sent: Friday, 10 October 2025 5:39 AM
To: Mark Haubner <mhau...@gmail.com>

To view this discussion visit https://groups.google.com/d/msgid/planetary-restoration/CALf2ri5ga1ksyVa_q82i1XAh2-hdNOFXC%2BOFXozuww5So6LHPA%40mail.gmail.com.

[Mark Haubner]

My thought precisely, Tom, except I'm much more of an "all-and" person at this point; from billions of small efforts plus large-scale policy swathes, all hands on deck right now. 

On Thu, Oct 9, 2025 at 12:16 Tom Goreau <gor...@globalcoral.org> wrote:

To view this discussion visit https://groups.google.com/d/msgid/healthy-planet-action-coalition/BY3PR13MB4994DF01503428BF549CF3E2DDEEA%40BY3PR13MB4994.namprd13.prod.outlook.com.

[rob de laet]

Hi Robert, 

Agree with Tom that we need to include ALL elements that bring cooling and calm weather extremes (which while related are not the same obviously). Increasing planetary reflectivity is important, but it’s not the whole picture. Let me stress again that the amazing cooling power of tropical rainforests should not be overlooked. Their power lies not only in their albedo effect as large cloud producing biomes but in their role as vast natural heat pumps which is driving evapotranspiration and transporting latent heat upward to the higher atmosphere and outward into space. Through this continuous phase change of water, forests export enormous amounts of solar energy from the surface to higher altitudes, where it is released as infrared radiation and dissipated to space. This latent heat transfer and the associated cloud formation are of a cooling magnitude comparable to current EEI on the warming side. Protecting and regenerating them (including transitioning open fields to agroforestry food production) have an outsized effect on temperatures locally and regionally and if done in a strategic way on sufficient areas at the right places, can increase rainfall hundreds of kilometers away, increasing the whole process. That’s why the restoration of tropical rainforests is so crucial: it reinstates the planet’s damaged temperature regulation system. By rebuilding the biotic pump and strengthening evapotranspiration cycles, we not only increase albedo but also reinforce the planetary cooling engine itself. Similar effects can be told about restoring coastal and ocean ecosystems such as mangroves, seagrass and coral reefs.  

These elements should definitely have a high priority in a strategic planetary climate rebalancing act. 

By the way, Ali Bin Shahid wrote a beautiful blog about it the other day, worth a read: #196: Trigger Points: Mapping the Fastest Paths to Climate Repair

#196: Trigger Points: Mapping the Fastest Paths to Climate Repair Ali Bin Shahid From Prediction to Repair

Best, 

Rob de Laet 

Project Lead Cooling the Climate

Member of the EcoRestoration Alliance

Fellow of Global Evergreening Alliance

Fellow fo the Schumacher Institute

Co-founder of Senang Eco Services

WhatsApp: +55 71 992617846

To view this discussion visit https://groups.google.com/d/msgid/healthy-planet-action-coalition/BY3PR13MB4994EF4E0621CEBAE9A6481ADDEEA%40BY3PR13MB4994.namprd13.prod.outlook.com.

[rob...@rtulip.net]

Tom, if your comment about either/or was directed at me, it misrepresents my position. 

 

Action is needed on both albedo and carbon, but the sequencing requires first building a coalition that includes groups who could be amenable to rebrightening but are hostile to decarbonisation. The climate will not be saved by a popular front of the political left.

 

Regards

 

Robert Tulip

To view this discussion visit https://groups.google.com/d/msgid/planetary-restoration/BY3PR13MB4994DF01503428BF549CF3E2DDEEA%40BY3PR13MB4994.namprd13.prod.outlook.com.

[Mike MacCracken]

There are some real mitigation approaches that can matter:

 

1. Slash emissions of methane and precursors to tropospheric ozone—these can lead to near-term reductions in radiative forcing.
2. Reverse deforestation—this not only cuts CO2 emissions but sustains the CO2 sink and reforestation can enlarge it.
3. Cut black carbon emissions at least as much as sulfate emissions—black carbon increases solar absorption, especially when the black carbon falls onto snow and ice.

So, don’t think of mitigation as just cutting CO2 emissions.

 

Mike

 

On 10/12/2025 7:02 AM EEST Alan Kerstein <alan.k...@gmail.com> wrote:

 

 

Robert,

 

I fully support your point “In this unsatisfactory context, insisting that cooling allies must sign up in advance to a full long-term scientific agenda risks being counterproductive” and in fact I would broaden it. HPAC should be careful about advocating the Triad exclusively as a package. People who focus on practical (vs. aspirational) solutions might, with some justification, regard emissions reduction and/or CDR at the needed scale within a relevant time frame to be wishful thinking, leading them to be skeptical about an organization that advocates these on an equal footing with rebrightening. To be clear, I personally support the Triad but but I also take to heart your point about the deep tension between effectiveness and coherence. Support for rebrightening might presently be a fringe position, but there could be a point when the script is flipped and the rebrightening advocates are rightly recognized as the hard-headed realists.

 

Alan

To view this discussion visit https://groups.google.com/d/msgid/healthy-planet-action-coalition/00e901dc3b26%240ffe6ac0%242ffb4040%24%40rtulip.net.

 

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[Robert Chris]

Hi RobertT (and everyone)

I am putting the finishing touches to my adaptation of the FaIR climate model.  In this endeavour I'd like to test it with your views of the plausible future trajectory for CO2 emissions, CO2 drawdown through CDR and deployments of SRM.  The model runs out to 2300, so if you could give me your thoughts on a range of likely outcomes for those three variables it would be really helpful.

The model is agnostic about the source of the emissions, CDR and SRM.

The way the model handles the data is a milestone value by a certain year.  There are three milestone for each variable.  The simple way to provide the inputs values is to fill in the blanks in the following:

annual CO2 emissions will reach XGtCO2 by 2XXX, then increase/fall to YGt by 2XXX. And then rise/fall to ZGt by 2XXX, where the years lie between 2025 and 2300.  No need to specify all three X, Y and Z, you might think, for example, that emissions will rise to 50GtCO2/yr by 2050 and then slowly decline to an irreducible minimum of 10GtCO2/yr by 2200.

CDR and SRM are defined in the same way, save that they both have a start year that needs to be specified and SRM is measured in Wm^-2.

If others want to send me your views on how emissions, CDR and SRM might play out, or if you're just interested to know what the surface temperature impact is of any particular combination of all three, just let me have your numbers.

The purpose of this exercise is to provide a quick and reliable sense of the plausibility and outcome of the many options open to policymakers.

Regards

RobertC

---

From: healthy-planet-...@googlegroups.com <healthy-planet-...@googlegroups.com> on behalf of rob...@rtulip.net <rob...@rtulip.net>
Sent: Sunday, October 12, 2025 04:12
To: 'Tom Goreau' <gor...@globalcoral.org>; 'Jan Umsonst' <j.o.u...@gmail.com>; 'Ron Baiman' <rpba...@gmail.com>

Cc: 'healthy-planet-action-coalition' <healthy-planet-...@googlegroups.com>; 'William Beckler' <bi...@bsec.org>; 'Aria Mckenna' <ar...@globalcoolingproductions.com>; 'Cara Fleischer' <ca...@creationcommunications.com>; 'Herb Simmens' <hsim...@gmail.com>; 'Jake Schwartz' <ja...@chesapeakeclimate.org>; 'Rafe Pomerance' <rafe.po...@gmail.com>; 'Michael MacCracken' <mmac...@comcast.net>; 'Healthy Climate Alliance' <healthy-clim...@googlegroups.com>; 'Planetary Restoration' <planetary-...@googlegroups.com>; 'Lucinda Shearman' <lucindas...@hotmail.com>; 'Bruce Melton -- Austin, Texas' <bme...@earthlink.net>

Subject: RE: [prag] RE: [HPAC] How Climate Intervention can Safely and Quickly Cool the Planet_HPAC NYC Climate Week_Sep. 26, 2025

To view this discussion visit https://groups.google.com/d/msgid/healthy-planet-action-coalition/00e901dc3b26%240ffe6ac0%242ffb4040%24%40rtulip.net.

[Alan Kerstein]

Robert,

I fully support your point “In this unsatisfactory context, insisting that cooling allies must sign up in advance to a full long-term scientific agenda risks being counterproductive” and in fact I would broaden it. HPAC should be careful about advocating the Triad exclusively as a package. People who focus on practical (vs. aspirational) solutions might, with some justification, regard emissions reduction and/or CDR at the needed scale within a relevant time frame to be wishful thinking, leading them to be skeptical about an organization that advocates these on an equal footing with rebrightening. To be clear, I personally support the Triad but but I also take to heart your point about the deep tension between effectiveness and coherence. Support for rebrightening might presently be a fringe position, but there could be a point when the script is flipped and the rebrightening advocates are rightly recognized as the hard-headed realists.

Alan

On Sat, Oct 11, 2025 at 8:12 PM <rob...@rtulip.net> wrote:

To view this discussion visit https://groups.google.com/d/msgid/healthy-planet-action-coalition/00e901dc3b26%240ffe6ac0%242ffb4040%24%40rtulip.net.

[John Nissen]

Hi Robert T,

I don't think we need a coalition with groups actually hostile to decarbonisation, but groups who would not put a priority on rapid decarbonisation if they understood the situation.  

Understanding the situation is where a "state of the planet" report card would be valuable, and we can produce one quite quickly.  There needs to be a short document which makes it clear that there is a climate crisis of such urgency that emergency cooling is required, with priority on the Arctic.  The emergency arises because of the radiative forcing which has built up since around 1980.  The Arctic is in meltdown, with not only excess radiative forcing from albedo loss but also incursion of warm water from the Atlantic (and to a lesser extent the Pacific) into the Arctic, e.g. Barents Sea.  There is also some radiative forcing from greenhouse gases.  

The only way to bring down the Arctic temperature is to counter the heating power flux into the Arctic with more than equivalent cooling power flux into the Arctic.  The heating power flux is estimated as around 1.0 petawatt.  So there needs to be a cooling power flux greater than 1.0 petawatt.   SAI is the only available technique to quickly scale to that level of cooling and halt the meltdown in the Arctic.  If the meltdown is not halted while there is still a good chance of doing so, then future generations (including the young people of today) are committed to living in a world devastated by catastrophic sea level rise and almost certainly catastrophic climate change.

How would we get credibility of such a report card, challenging the orthodoxy on climate change?  It would be good to get support from a fossil fuel company and/or a philanthropic group committed to effective altruism.  Can anyone suggest a sympathetic contact to start the ball rolling?

Cheers, John

 

To view this discussion visit https://groups.google.com/d/msgid/healthy-planet-action-coalition/00e901dc3b26%240ffe6ac0%242ffb4040%24%40rtulip.net.

[Chris Vivian]

Robert,

 

Have you seen this Climate Solutions Simulator:

https://www.climateinteractive.org/en-roads/

 

Also, this Climate Trace ‘Comprehensive Emissions Insight’ website may be of interest: https://climatetrace.org/

 

Chris.

To view this discussion visit https://groups.google.com/d/msgid/healthy-planet-action-coalition/VI1P194MB03986AB8C29E8157CF46D4FCFCEDA%40VI1P194MB0398.EURP194.PROD.OUTLOOK.COM.

[Robert Chris]

Hi Chris

En-roads is not user-friendly unless you're a pretty sophisticated user and it doesn't handle SRM, or didn't when I last looked at it.

Climate Trace tells you what's just happened but, as far as I can tell, does not provide any forecasting tools to say what different emissions, CDR and SRM scenarios will do to GSAT over the next couple of hundred years.

My adapted FaIR model is intended for lay users to answer simple questions like what happens to GSAT if we don't reduce emissions until next century, and how much CDR and/or SRM would we have to do to keep warming below whatever threshold you care to set.

If you know of something that does that and could be used by an intelligent 14-year-old, let me know.  (I'm assuming that most policymakers have the mental capacity at least of an intelligent 14-year-old.  Do you think I'm being over generous?)

The idea is that anyone can run this model on their own computer and get instant reliable answers.  No need to consult a climate scientist, if you can find one with the time and inclination to answer your questions, and who's probably more concerned about intellectual rigour than about climate risk management.

Regards

Robert

---

From: Chris Vivian <chris....@btinternet.com>
Sent: Sunday, October 12, 2025 20:50
To: 'Robert Chris' <robert...@gmail.com>; rob...@rtulip.net <rob...@rtulip.net>; 'Tom Goreau' <gor...@globalcoral.org>; 'Jan Umsonst' <j.o.u...@gmail.com>; 'Ron Baiman' <rpba...@gmail.com>

Cc: 'healthy-planet-action-coalition' <healthy-planet-...@googlegroups.com>; 'William Beckler' <bi...@bsec.org>; 'Aria Mckenna' <ar...@globalcoolingproductions.com>; 'Cara Fleischer' <ca...@creationcommunications.com>; 'Herb Simmens' <hsim...@gmail.com>; 'Jake Schwartz' <ja...@chesapeakeclimate.org>; 'Rafe Pomerance' <rafe.po...@gmail.com>; 'Michael MacCracken' <mmac...@comcast.net>; 'Healthy Climate Alliance' <healthy-clim...@googlegroups.com>; 'Planetary Restoration' <planetary-...@googlegroups.com>; 'Lucinda Shearman' <lucindas...@hotmail.com>; 'Bruce Melton -- Austin, Texas' <bme...@earthlink.net>

[rob...@rtulip.net]

Thanks Robert.  My suggested model trajectories are as follows

 

• Emissions constant 50 GtCO2e/y to 2300
• Drawdown linear increase from 2Gt in 2025 to 100 GtCO2e/y in 2050 then constant to 2300
• SRM starting in 2030 and returning planetary average temperature/RF to pre-industrial by 2070, then maintaining constant temperature to 2300.

 

I expect a shift to a circular algae economy, with algal biofuel gradually replacing fossil fuels, and emissions used as feedstock for large scale ocean based algae production.

 

Regards

 

RT

[Robert Chris]

Hi RobertT

This is a great test for the model!  First, I'll give you the results and later, I'm going to check them.  The reason for this is that the model says that with those emissions and CDR profiles and with no SRM, we'll be headed right into another ice age!  Warming peaks at 1.9^oC in 2039 and then falls to -2^oC by 2150 and -11^oC by 2300.  By 2100 CO₂ is down to 239ppm and by 2300 it's just 6ppm!

Is that what you were expecting?  End of life on Earth!

At first glance, it doesn't seem unreasonable.  If by 2050 we're annually drawing down a net 50GtCO₂, then in 50 years we'd have pulled out 2,500GtCO₂ which is slightly more than we've emitted to date.  

However, you've specified CO₂e.  The native FaIR model treats each of 83 forcing agents separately but that makes it unusable by normal people.  In WTF all the non-CO₂ forcing agents are handled as a single combined forcing agent.  The above results are based on GtCO₂ not CO₂e and I think this means that the non-CO₂ forcing agents are being double counted.

I can remove that by scaling back your figures by the factor that the model uses to account for the non-CO₂ forcing agents.  This currently defaults to 20%.  That still generates an ice age.  Warming peaks at 1.8^oC in 2038 and then falls to -1.1^oC by 2150 and -5.1^oC by 2300.  By 2100 CO₂ is down to 263ppm and by 2300 it's 63ppm.  That also seems to make sense.  The slightly lower and earlier peak is because emissions are lower in the early years while the CDR is being scaled up.  Once the CDR is scaled, it's removing CO₂ at a slightly slower rate.

Assuming WTF has got these figures more less right, it tells us that with CDR at that level we don't need to worry about doing any SRM - that'll make a lot of people very happy - and we can do a lot less CDR than you propose.  The model suggests that keeping emissions where you suggested and reducing the CDR to half of what you suggested, warming peaks at 1.9^oC in 2047 and remains more or less at that level.  CO₂ slowly declines getting to 400ppm by 2300.  If we set the CDR at ​57GtCO₂e/yr warming steadily declines from the same peak to 1^oC.

I'd also welcome your assessment of the likelihood of delivering these levels of CDR.  To be clear, I'm not asking how it could be done, but rather in the real world, what are the chances that it will be.  If I'm a policymaker in 2025 how confident can I be that globally, with all the real-world pressures over the next 25 years, we could get to 57GtCO₂e CDR by 2050.  As a policymaker, I need a coherent answer to that question if I am going to devote scarce resources to such a project.  If you want to duck that question, try this one - what are the criteria you think will convince whoever needs to be convinced that this is a sufficiently good idea to warrant the investment of the necessary resources to make it happen, given all the alternatives.

Thanks for this and I'm very happy to try out some more scenarios. 

Regards

RobertC

---

From: rob...@rtulip.net <rob...@rtulip.net>
Sent: Monday, October 13, 2025 15:20
To: 'Robert Chris' <robert...@gmail.com>; 'Tom Goreau' <gor...@globalcoral.org>; 'Jan Umsonst' <j.o.u...@gmail.com>; 'Ron Baiman' <rpba...@gmail.com>

[Tom Goreau]

Could this projection just be yet another example of extrapolating model outputs beyond the limits of the data that define them?

 

Linear, not Systems thinking, see:

 

https://en.wikipedia.org/wiki/Thinking_In_Systems:_A_Primer

[Robert Chris]

Hi Tom,

Of course it could!  Silly question.

However, your 'linear thinking' put down is itself a good example of linear thinking.  Systems thinking does not imply that linear thinking has no place in thinking.  On the contrary, it implies that linear thinking is not sufficient, not that it's not necessary.

The numbers are the numbers.  They come out of a model that has many non-linear functions within it (quadratic, exponential and logarithmic).  What it doesn't have is any randomisation to account for events that haven't yet been conceived of.  How would you do that?

The model is just a tool.  The systems thinking comes into play when thinking about how to use it.

On the specific example that RobertT proposed, you may well regard the model results as an inappropriate and misleading extrapolation, and that OK because it provokes a useful discussion.  You could ask whether RobertT's suggested escenario is remotely plausible.  There are all sorts of reasons why it might not be.  You could offer some explanation why the model results are demonstrably 'beyond the limits of the data that define them'.  That wlould be helpful.  You might offer some useful suggestions about how to know when a model has over-reached itself.  That would be most welcome.

Regards

Robert

---

From: Tom Goreau <gor...@globalcoral.org>
Sent: Monday, October 13, 2025 16:59
To: Robert Chris <robert...@gmail.com>; rob...@rtulip.net <rob...@rtulip.net>; 'Jan Umsonst' <j.o.u...@gmail.com>; 'Ron Baiman' <rpba...@gmail.com>

[Tom Goreau]

As you know very well, ALL models bear their linear caricatures, but only within a most circumscribed range of trustworthy calibration data, and not necessarily much beyond them. AI is likely to miss it. Sorry to bore with pedantry, but clearly not everyone has the systems thinking background that you do.

[Ron Baiman]

Dear Robert, 

It is interesting that we have a similar political economic assessment of why much of the right (esp. in the US) is so dug in against acknowledging that the climate crisis is real,  imminent and calmatious on a global scale, not a far away minor issue as Musk is now claiming - and in fact of course is the greatest existential threat that humanity as a whole has ever faced. This is because they view government led and especially globally coordinated climate policies as a threat to global capitalism and to their wealth and power. Gone are the days (at least in the US) when "environmentalism" was viewed as a bi-partisan non-political issue that all could agree on as nobody wanted to live in a polluted and destroyed natural environment. And the reason for this is precisely (as I believe you would agree) because it became apparent that climate policy required large scale national and global planning and coordination that is antithetical to free market capitalism and unfettered pursuit of self-interest and wealth accumulation.  

Similarly, I think we (and most HPACers) agree that a "socialist revolution" is not a practical solution to the most urgent problem of near-term global warming that we are facing, as the time clock of human social and political economic systemic evolution is much slower that of climate change. As I said in response to a discussion about this that we had our NYC Climate Week event (see recording), if we were serious about tackling the fundamental problem of getting GHGs out of our atmosphere and oceans at the breakneck speed that we should be (even then we'd probably need to "shave the peak" with cooling but it could be for decades rather than centuries as increasingly appears to be the case now) we would have to have a global "war economy" against the greatest "climate change enemy" (of our own - largely unintentional - making) that humanity has ever faced!  But of course, this is just not realistically going to happen, at least in our lifetimes as far as we can tell. 

Where we differ I think is on the current policy implications of all this.  My thinking is that though we have to be promoting cooling as much as we can as the immediate urgent priority, we also have to also recognize that in the long-term free-market laissez faire capitalism is going to have to move in a substantially more "socialist" direction - that is more public policy and more public constraints and more international and global cooperation - if we are going to "rapidly" (hopefully decades rather than centuries) get through the climate crisis without regressing to "solitary, poor, nasty and short" (quoting Hobbes) existential futures for our offspring (and increasingly for living humans) as stated in our NYC Climate week description. So I think it's quite important, particularly at this moment, to not let the right off the hook on their delusionary fantasies that climate is not something we need to worry about or that somehow capitalism is going to save us. Rather we need to be fully engaged in this long-term project even as we understand that socialist revolution is not a solution for the short-term. 

Best,

Ron

[Ron Baiman]

Postscript -  One of the reasons that I was particularly interested in organizing this climate event in NYC was to engage with democratic socialists in that city (some of them my very old political comrades) who are it appears about to elect the first democratic socialist mayor of a major city in the US in a very long time.  Again - per the recording - I think we were able to have this discussion at the event! 

Sent from my iPhone

On Oct 13, 2025, at 5:43 PM, Ron Baiman <rpba...@gmail.com> wrote:



[Aria Mckenna]

Robert,

There are so many presumptions in what you wrote here that I thoroughly disagree with that I do not believe I properly have time to get into...

However, I must not allow the entire thing to go unaddressed...

First of all in regards to trump's "win". 

- it is well documented that the only way he could have possibly won is because of massive voter disenfranchisement, which has been thoroughly documented by greg palast. It is a travesty that we have allowed that well documented election interference to stand.

... but beyond this and many other issues I have with the election - trump and the GOP are masters of messaging. 

Short, simple, with very few syllables repeated over and over and over and over again, until people begin to believe these statements are true. 

I have attempted to influence the organization in this manner but fear I have not made much progress on it. The problem is that when people feel they have truth and data on their side, they may not believe it is as important to hone their messaging. 

The likes of the koch brothers knew the importance of owning the radio waves and funding think tanks that only focused on how to essentially, brainwash people into believing what they wanted them to believe. 

Robert, it's interesting that you blame the desire to maintain the status quo as the reason why trump "won", and yet there is a complete dismantling of that status quo happening right now. Trump ran on false populism. And yes he also ran on greed and fear. Right now, capitalism is exploding to the point that compassion for human beings is being left in its wake.

What's more, you seem to want to uphold capitalism as a monolith, that we dare not question or bump up against. And yet the brutal reality is that capitalism IS what created the climate crisis. It's what created climate denial, and its created water crises, toxic poisoning, premature deaths... and yes, inequality and major environmental justice issues. 

If we solve the climate crisis, but leave the world in shambles with decimated water systems and people everywhere dying of toxic poisoning, i just don't find any comfort in that. 

That being said much of this is written in generalizations, and of course, there is such a thing as conscious capitalism. There are many solutions to this interconnected web of issues that created the world we are currently living in. 

But we must not oversimplify the solution to one problem while we create many, many, many more problems in our wake. 

(Please excuse typos and talk to text! 😆 - Sacrificing email perfection to optimize productivity and health!)

Warmest Thanks For Everything You Do,
Aria McKenna
Brand: "Saving Planet Us"
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Watch My 'BECOMING THE CHANGE' Roundtable at:
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https://www.greentv.com/aboutus
   

[rob...@rtulip.net]

Hi Robert

 

Thanks, those were just top of my head numbers without calculation to get the ball rolling, and the response looks correct.  It indicates the value of defining the range of combinations that could restore and sustain Holocene temperature or slightly above.  I had not really thought about the implication of extending for 275 years.

 

I have now done some rough calculations for a revised set of numbers. 

• Emissions continue at 50 GtCO2e/y until 2300
• Increase GHG removal by 4 GtCO2e/y until 2060, then decrease removals by 6 GtCO2e/y until 2072, then decrease by 2 GtCO2e/y until 2082, when net zero is achieved
• GGR to achieve net zero emissions from 2082 to 2300, leaving an ongoing excess of 150 Gt over the Holocene baseline.
• intensive global SRM starting in 2030 to restore Holocene temperature and radiative forcing by 2070, followed by ongoing regional SRM to optimise weather.

 

My basis for these suggestions includes the following assumptions:

1. emissions will continue on a market driven basis;
2. emission reduction can most easily and effectively be accelerated by CDR after the pipe, not by preventing combustion before the pipe as now envisaged in COP;
3. the work of climate management will require a combination of GGR and SRM, with decarbonisation a marginal factor;
4. a circular economy will enable profitable CDR producing fuel, food, feed, fish, fabric, forests and fertilizer (7F);
5. the world will be in a much safer place if the challenge is fine tuning to prevent an ice age rather than panicking to prevent a hothouse;
6. it will be far easier to reduce ongoing GGR and SRM interventions before they get too big than to ramp them up after heat gets too bad;
7. the goal should be to safely remove excess GHGs as fast as possible without damaging the economy;
8. CDR must ramp up fast to slow ocean acidification, mainly by expanding ocean photosynthesis.
9. SRM must be deployed globally as soon as possible to minimise risks of extinctions and catastrophic disruption
10. ongoing SRM managed with AI will be needed to optimise regional climate conditions;

 

The Global Carbon Budget 2024 calculates that of ~2,605 GtCO₂ emitted to date, about 40% remains in the atmosphere (285 GtC ≈ 1,044 GtCO₂), 26% has been taken up by the ocean (185 GtC ≈ 678 GtCO₂), ~32% by land, with ~3%) accounting imbalance.  That means the removal task from air + ocean together is ~1,720 GtCO₂.    Net removal averaging 30 GtCO2e/y would achieve this by 2084, after which the goal should be net zero emissions.  The idea of achieving net zero via decarbonisation is absurd and dangerous and stupid.  Intensive SRM is needed alongside a GGR ramp up to prevent the planet accidentally tipping into a hothouse with resulting mass extinction due to unforeseen fragilities and sensitivities.

 

Here is an Excel chart I made for these calculations, showing my suggested GGR path

 

[rob...@rtulip.net]

Hi Ron

 

Your comments on political economy raise some thorny dilemmas that are hard to untangle.  My view is that climate stability will require alliances with industries who depend on fossil fuels, which in turn requires framing arguments in ways that could build trust with such audiences.  That involves a critique of partisan attitudes within the climate action movement. I have explored these themes in a few recent HPAC emails, including to Aria last Friday with an attachment on the ideological roots of decarbonisation, and to Robert Chris on 29 September.

 

I have a slightly different take on your view that the political right “view government led and especially globally coordinated climate policies as a threat to global capitalism and to their wealth and power.”  That is true regarding proposals for decarbonisation, but not necessarily true for climate policy overall. 

 

Globally coordinated policies on sunlight reflection do not intrinsically need to pose a threat to capitalism.  This is a big part of why the neo-communist wing of the climate movement is so hostile to geoengineering, because they see climate policy as a means to the end of overthrowing capitalism.  By ‘neo-communist’ I mean an illiberal, fossil-abolitionist, state-led program that forecloses pluralist debate and treats dissent as illegitimate.

 

Energy Secretary Chris Wright perceives decarbonisation as a Big Lie, leading to higher rather than lower energy prices. He argues, rightly in my view, that renewable energy advocates ignore the need to include major factors such as reliable baseload backup and transmission in the overall renewable system cost.  That debate has been central to the breakdown of trust toward academic energy modelling among conservative communities.  On top of this fiscal problem there is also the tribal problem, that decarbonisation is promoted by the left as part of a suite of progressive policies that are anathema to conservatives. 

 

Geoengineering is caught up in this tribal camp division, generally seen as standing on the side of progressive science against reactionary irrationality.  This way of seeing the division will change if conservatives take a lead on promoting sunlight reflection.  After all, climate denial is a recipe for collapse, which is not good for anyone’s wealth or power.

 

Climate policy is now seen through the prisms of energy policy and partisan division.  That means the whole scientific agenda of climate analysis, and its major security implications, gets swept up in the political hostility many on the right have toward decarbonisation.  However, a climate policy that decoupled climate from energy by proposing cooling and GGR alongside ongoing fossil fuel use could be attractive to many on the right.  That is a highly worthwhile goal as it would bring investment, influence, skills, debate and resources into the geoengineering movement.  The aim would be to replace politically driven subsidies for wind and solar with government funding for climate on the basis of cooling return on investment, as a security investment. 

 

This raises the existential problem of whether people see left wing community identity or reversing global warming as more urgent.  If the latter, shifting climate policy away from the ideology of redistribution and into the framing of security, through an Albedo Accord, could be an entry point to build a bipartisan coalition of support.  Climate collapse is a security threat, with major risks of refugee flows, sea level rise, extreme weather, economic crisis and other systemic disruptions.  Collapse risk can be mitigated by SRM and GGR, but hardly at all by decarbonisation.

 

I criticise revolutionary thinking to emphasise the futility of UN calls to halve emissions in this decade, which is a thoroughly unrealistic and revolutionary call.   My view is that policy has to be pragmatic, realistic, incremental, scientific and respectful, and that decarbonisation as a climate strategy fails on all those counts, whereas sunlight reflection succeeds.  Renewable energy is great where local conditions support it on environmental and cost grounds, but pretending it could influence the climate is delusional.

 

You say “it became apparent that climate policy required large scale national and global planning and coordination that is antithetical to free market capitalism.” The right does not object to the need for planning and coordination as such.    Their objection is to the globally coordinated plan of the climate action movement that aims directly at destroying the fossil fuel industry.  It would be entirely possible to develop a coordinated cooling plan that accepted ongoing use of fossil fuels.  This can be compatible with HPAC’s call for accelerated emission reduction, through a focus on building new industries that use concentrated emissions as algae feedstock, aiming to ramp up CDR bigger than total emissions.

 

The political right is perfectly happy to throw trillions of dollars at globally coordinated military plans and policies to protect capitalism.  An Albedo Accord could deliver a similar level of realism in responding to climate threats, by decoupling climate and energy in order to coordinate global response to the security threat of heat.

 

I am sympathetic to your discussion of socialism as just the need for public policy, public constraints and more international and global cooperation.  That walks back a long way from traditional concepts of socialism as government ownership of the means of production and the polarised language of class struggle.  Indeed, it is even compatible with Hayek’s call in The Constitution of Liberty for well-regulated markets, something his laissez-faire acolytes miss.

 

By the way, I like your new word ‘calmatious’.  I wonder how often new terms start off as humble typos?  Calmatious is like calamitous, but with unnerving calm; the serene composure that somehow accompanies a disaster.

 

Regards

 

Robert Tulip

[Ron Baiman]

Hi Robert, 

See response in red below.

Best,

Ron

On Tue, Oct 14, 2025 at 8:56 AM <rob...@rtulip.net> wrote:

Hi Ron

 

Your comments on political economy raise some thorny dilemmas that are hard to untangle.  My view is that climate stability will require alliances with industries who depend on fossil fuels, which in turn requires framing arguments in ways that could build trust with such audiences.  That involves a critique of partisan attitudes within the climate action movement. I have explored these themes in a few recent HPAC emails, including to Aria last Friday with an attachment on the ideological roots of decarbonisation, and to Robert Chris on 29 September.

 

I have a slightly different take on your view that the political right “view government led and especially globally coordinated climate policies as a threat to global capitalism and to their wealth and power.”  That is true regarding proposals for decarbonisation, but not necessarily true for climate policy overall. 

 

Globally coordinated policies on sunlight reflection do not intrinsically need to pose a threat to capitalism.  This is a big part of why the neo-communist wing of the climate movement is so hostile to geoengineering, because they see climate policy as a means to the end of overthrowing capitalism.  By ‘neo-communist’ I mean an illiberal, fossil-abolitionist, state-led program that forecloses pluralist debate and treats dissent as illegitimate.

What you call "neo-communists" we on the democratic left have for years called "sectarians".  In my experience, at least in the US, such groups are now extremely marginal and rarely encountered as the Democratic Socialist of America (DSA) has grown to become the overwhelmingly dominant organization of "publicly out" socialists in the US.for which the Mandani insurgency is a primary example.  On the other hand the Republican party Trump cult of climate change deniers, and racist and misogynistic fascists with little to no respect for democratic norms and laws are indeed leading efforts to [my slight  edits] "foreclose pluralist debate and treat dissent as illegitimate".  In short, your "neo-communists" are  (at least from the US perspective) almost entirely fictional in terms of political power and influence - like Trump's  organized and funded "antifa" "enemy from within" boogeyman.

 

Energy Secretary Chris Wright perceives decarbonisation as a Big Lie, leading to higher rather than lower energy prices. He argues, rightly in my view, that renewable energy advocates ignore the need to include major factors such as reliable baseload backup and transmission in the overall renewable system cost.  That debate has been central to the breakdown of trust toward academic energy modelling among conservative communities.  On top of this fiscal problem there is also the tribal problem, that decarbonisation is promoted by the left as part of a suite of progressive policies that are anathema to conservatives. 

We have, I believe, a factual disagreement here. In my view a rapid green transformation of the global economy is fundamentally dependent on the role out of large public sector programs like a global high-speed grid to achieve universal and affordable coverage just as a national electric grid, highway system, internet backbone, and other large scale infrastructure programs were developed. A grid could greatly alleviate the storage and dispatchability problems that will not in my experience (I started my professional career and in utility regulation) be delivered by for-profit investors alone (see for example this excellent podcast on New Deal programs and rural electrification in the US:  https://podcasts.apple.com/us/podcast/how-the-new-deal-changed-american-power-w-sandeep-vaheesan/id1469270123?i=1000684633138

The conservative community are unfortunately in my view too ideologically influenced by  the free market mythology of Neoclassical economics representing a legitimation ideology supporting the status quo backed up by capitalist class political and economic power exacerbating and undermining democracy at current level of wealth and income inequality. For more on all this see my climate paper and book here: https://drive.google.com/drive/folders/1O1SZozhiyQ_PnwzA4lDVZycYp_05K1Ci?usp=sharing

Geoengineering is caught up in this tribal camp division, generally seen as standing on the side of progressive science against reactionary irrationality.  This way of seeing the division will change if conservatives take a lead on promoting sunlight reflection.  After all, climate denial is a recipe for collapse, which is not good for anyone’s wealth or power.

 

True but almost completely on the right in the US. 

 

Climate policy is now seen through the prisms of energy policy and partisan division.  That means the whole scientific agenda of climate analysis, and its major security implications, gets swept up in the political hostility many on the right have toward decarbonisation.  However, a climate policy that decoupled climate from energy by proposing cooling and GGR alongside ongoing fossil fuel use could be attractive to many on the right.  That is a highly worthwhile goal as it would bring investment, influence, skills, debate and resources into the geoengineering movement.  The aim would be to replace politically driven subsidies for wind and solar with government funding for climate on the basis of cooling return on investment, as a security investment. 

As noted above and in my previous post, I factually disagree. My thinking is that only a "war economy" (with globally coordinated mandatory policies - like the now abandoned Kyoto Accord per my papers - could possibly deliver a green global economy within decades.  Private incentives and profit are powerful incentives but they are not nearly enough to fight the climate and ecosystem calamities that we now face. 

 

This raises the existential problem of whether people see left wing community identity or reversing global warming as more urgent.  If the latter, shifting climate policy away from the ideology of redistribution and into the framing of security, through an Albedo Accord, could be an entry point to build a bipartisan coalition of support.  Climate collapse is a security threat, with major risks of refugee flows, sea level rise, extreme weather, economic crisis and other systemic disruptions.  Collapse risk can be mitigated by SRM and GGR, but hardly at all by decarbonisation.

 

Yes. It is a massive global security threat and at some point this may be how global cooling deployment is finally initiated. But shaving the peak alone is not enough. Emissions reductions and drawdowns have to be accomplished at breakneck speed or we may be condemning our offspring to centuries of misery. 

 

I criticise revolutionary thinking to emphasise the futility of UN calls to halve emissions in this decade, which is a thoroughly unrealistic and revolutionary call.   My view is that policy has to be pragmatic, realistic, incremental, scientific and respectful, and that decarbonisation as a climate strategy fails on all those counts, whereas sunlight reflection succeeds.  Renewable energy is great where local conditions support it on environmental and cost grounds, but pretending it could influence the climate is delusional.

 

Another factual disagreement. In the long term this is the only way we can regenerate a stable climate and ecosystem and we need to work on it as fast as possible starting now.  

 

You say “it became apparent that climate policy required large scale national and global planning and coordination that is antithetical to free market capitalism.” The right does not object to the need for planning and coordination as such.    Their objection is to the globally coordinated plan of the climate action movement that aims directly at destroying the fossil fuel industry.  It would be entirely possible to develop a coordinated cooling plan that accepted ongoing use of fossil fuels.  This can be compatible with HPAC’s call for accelerated emission reduction, through a focus on building new industries that use concentrated emissions as algae feedstock, aiming to ramp up CDR bigger than total emissions.

My apologies for perhaps moderating my view to the point of inaccuracy.  I don't think we just need coordination, we need mandatory programs and massie wealth and funding transfers, and none of this, especially the global part, is favored by the right who have simply become the servants of a megalomaniac and his billionaire and fossil-fuel  interest henchmen and women - at least in the US.

 

The political right is perfectly happy to throw trillions of dollars at globally coordinated military plans and policies to protect capitalism.  An Albedo Accord could deliver a similar level of realism in responding to climate threats, by decoupling climate and energy in order to coordinate global response to the security threat of heat.

 

Perhaps. But the right, at least in the US prefers to simply deny that climate change is a serious problem as they recognize that acknowledging that it will (rightly) not stop at global cooling, and cooling alone cannot solve our fundamental crises. 

I am sympathetic to your discussion of socialism as just the need for public policy, public constraints and more international and global cooperation.  That walks back a long way from traditional concepts of socialism as government ownership of the means of production and the polarised language of class struggle.  Indeed, it is even compatible with Hayek’s call in The Constitution of Liberty for well-regulated markets, something his laissez-faire acolytes miss.

Democratic socialists have long embraced the market and decentralized agency (not exclusively capitalist "ownership" as this is often exploitative, and at current extreme and growing levels undermines basic democracy and a rapid global climate change response)  are important aspects of capitalism.  But markets and for profit production alone will not work. See for example this critique: https://drive.google.com/file/d/1CvtsusCMhhKc0U1VOzBXxaAsFzDyW6EJ/view?usp=sharing  coupled with this: https://drive.google.com/file/d/1_A7pcahOTlEdcyvEzqnAMLDzuzCWhare/view?usp=sharing

[Ron Baiman]

* Democratic socialists have long embraced the market and decentralized agency (not exclusively capitalist "ownership" as this is often exploitative, and at current extreme and growing levels undermines basic democracy and a rapid global climate change response)  are important aspects of social, political and economic organization.*

[rob...@rtulip.net]

Hi Alan

 

Your comment here summarises a key theme in this thread, exploring how cooling alliances can cross political divides.  I particularly endorse your suggestion that rebrightening advocates will be rightly recognized as the hard-headed realists.  In politics, realism means the ability to see the balance of forces, and negotiate practical and durable outcomes, engaging with the transition problem of how we can move from our current situation toward desired goals.  By contrast, idealism imagines a result but lacks a practical way to achieve it.

 

My sense is that a failure to cross the polarised division between left and right guarantees failure of realism and thus failure to cool.  Unless the commercial world, who largely take a right wing view about politics, can be convinced of the viability and necessity of cooling, it simply will not happen.  Their powers of influence and funding will simply overwhelm arguments that they do not trust.  A conversation within progressive communities is necessary but not sufficient.  That means the negotiating task must assess what is essential and what is optional to form a bipartisan cooling lobby, a business-science alliance. 

 

The essential near-term priority is sunlight reflection because it alone can quickly constrain heat. As I have argued, this can be achieved through an Albedo Accord modelled on the Montreal Protocol.  Sequencing the Triad has to prioritise rebrightening now through advocacy and governance proposals, alongside an approach to emissions reduction and GGR that is supported by affected industries.  On your separate question about carbon tax, I am sceptical.  Political opposition to higher energy prices from major industries and voter blocs would generate a fruitless debate, negating possible theoretical benefit of going down this path in the short term.

 

Opposition to sunlight reflection is often passionate but movable. On the right, some assume geoengineering is a left-wing Trojan horse; on the left, some assume it’s a right-wing conspiracy. Both narratives fail to see the security urgency and threat of heat, and can be defused by a business–science alliance that treats cooling as an urgent measurable safety intervention, with clear governance and science. Shift the frame from ideology to risk management, security, science and public safety, and most stakeholders can be persuaded or become marginal.

 

Social mapping can identify who could support or oppose sunlight reflection and why. Likely allies include insurers and reinsurers, shipping and ports, tourism, fisheries and agriculture, energy producers, defence and emergency services. If significant industries see a credible strategy that meets their interests — risk reduction, asset protection, costed pilots with measurable outcomes and transparent governance — they can become core supporters.

 

Regards

 

Robert Tulip

 

My view is that sunlight reflection has to become the most essential and urgent cooling priority, in view of its unique ability to quickly constrain heat.  Social mapping can identify who could support or oppose sunlight reflection and why.  If significant industries could become sympathetic through the provision of a strategy that meets their interests,   

 

Opponents of sunlight reflection hold views that at times are passionate but which I believe can rapidly be changed or marginalised.  The Trumpite opposition is driven by the false assumption that geoengineering is a left wing conspiracy.  Similarly, left wing opposition seems to assume geoengineering is a right wing conspiracy.  Both can readily be confronted by a business-science alliance that recognises cooling as the most urgent climate task.

 

 

From: healthy-planet-...@googlegroups.com <healthy-planet-...@googlegroups.com> On Behalf Of Alan Kerstein

Sent: Sunday, 12 October 2025 3:02 PM
To: rob...@rtulip.net

To view this discussion visit https://groups.google.com/d/msgid/healthy-planet-action-coalition/CAH-gPYGP3fFu3cMBjzLmOL-rC3Y1rWOzWVeDGd_f-jCiX8g2SQ%40mail.gmail.com.

[H simmens]





Hi Alan,

Your recent post made the following observation:

“HPAC should be careful about advocating the Triad exclusively as a package. People who focus on practical (vs. aspirational) solutions might, with some justification, regard emissions reduction and/or CDR at the needed scale within a relevant time frame to be wishful thinking, leading them to be skeptical about an organization that advocates these on an equal footing with rebrightening.”

To be clear HPAC in its mission statement does not advocate nor make any judgments about the relative priority or scale of the three pillars of the triad. 

We advocate that the world community must come together to develop an equitable and science based plan incorporating the triad in such a way as to ultimately reduce temperature increases to well below 1° C above the pre-industrial baseline. 

We also include transformative adaptation and regeneration as essential components of our advocacy. 

In addition any direct climate cooling interventions need to be shown to be safe and effective, characteristics that remain to be authoritatively confirmed. 

The official Mission statement which was first adopted by the Steering committee early in 2024 was reaffirmed during the strategic planning process that took place at the end of 2024 and remains at our core. 

Here is the mission statement in full:

We advocate the world community urgently come together to carry out an equitable science base plan of action that includes what HPAC calls the Climate Triad:

- Directly cooling the climate through sunshine reflection ecosystem restoration and other safe and effective means

- Accelerating emission reductions

- Deploying large scale removal of atmospheric carbon dioxide and other greenhouse gases

The goal of these actions along with enhanced and transformative adaptation and regeneration measures is to reduce the average global temperature increase to well below 1° C in the coming decades. 

Doing so will sharply reduce weather extremes, slow or stop the collapse of key ecosystems and help ensure a livable planet for humanity and the natural world.”

Despite the fact that the majority of commenters on our list over the years debate the relative merits of the various components of the triad it is not within our official purview to make these judgments - which require scientific, political, economic and equitable assessments that are well beyond our capability or remit. 

It would be the height of arrogance for the nine older Caucasians (eight of whom are male ) who serve on the SC, every one of whom hails from the Global North from only two countries and whose professional backgrounds do not span many disciplines to attempt to advocate on behalf of the other 95% of the world‘s population that do not share our demographic, economic or geographic characteristics.  

I think it’s fair to say that the HP membership also is consistent with the demographic and geographic profile of the Steering Committee members. 

Nor is the science and technology anywhere near the point where such a plan can be confidently articulated without intensive and extensive additional knowledge generation and international consensus making efforts. 

I’m afraid based upon the conversations I’ve seen at the Steering Committee and on the list that this fundamental principle of HPAC is honored more in the breach than in the observance however. 

Herb

Herb Simmens

Author of A Climate Vocabulary of the Future

“A SciencePoem and an Inspiration.” Kim Stanley Robinson
@herbsimmens
HerbSimmens.com

[Ron Baiman]

Hi Alan,

I actually used the "mixed economy" label n the NYC climate week discussion (see Q&A part of the recording) that it worked pretty well for a while in the post war period in the US until (I think - I don't remember my exact words) the capitalists basically took over the government and destroyed the middle class.  I would add that doing away with New Deal norms by union busting and regulatory safeguards like campaign funding regulation were key to this. 

So yes, at some level the political issue is the sway and power of social choice versus "individual" (including class-based "private property" in the form of control over the work of other people) choice.  Per the history, see references in my response to Robert, I believe that if we humans were serious about responding the greatest existential threat we've ever faced  that is  barrelling down upon us at breakneck speed we would go into the kind of global "war economy" configuration that enabled democracy (and Stalinist Communism) to defeat fascism (that was also based on a "war economy'). 

Subsequent post-war New Deal and much more extensive Social Democratic programs in Europe and other advanced countries, and the US, built the middle class, reduced inequality, and greatly expanded democracy  and opportunity (though in the US not as much for non-whites - it was not perfect!). However, as this regime reverted back to a more deregulated - fewer restraints on deploying wealth to take over political power- "free-market" system, inequality has surged and democracy has plummeted (again mostly referring to the US). 

So politically I guess I'm saying that if we were serious, and if democracies are able to step up to the challenge of climate change as they did for fascism - we would again be reasserting the importance of social choice and reducing the sway of capital over human civilization - that is move more decisively in a "socialist" direction with 50% or more of GDP based on public funding and democratic policy as is/was the case in the most advanced social democracies in Europe - and not simply go back to the (weakest of social democracies) US post-war "mixed economy", at the global level,  as this is the only imv way to construct a truly sustainable human civilization over the long term (again see references from previous post).

On the strictly economic policy front - carbon taxes can be useful plus more generally Emissions Trading Systems plus even more generally a "global backstop" updated Kyoto Accord that would include mandated international treaties forcing write-offs of fossil fuel infrastructure- that would all need to be coupled with large scale redistribution to make all of this palatable to the working class and developing world -   would be among the many tools needed to make a "speedy" hopefully within decades transition to a green economy. See for example section 4 of this paper for more details: https://drive.google.com/file/d/1WNrZbVd17gRR9Fz8gaEt7BXzR-ZOrvzI/view?usp=sharing

Best,

Ron

[Robert Chris]

Hi Herb

 I don't disagree.  Indeed, I almost agree! 😉

The point I'd make is that there's unlikely to be much, if any, progress on achieving 'some rough consensus as to an operational definition and description of safety and effectiveness' of SRM until there's some rough consensus on the need for it.  Why bother to talk about how to make safe something you've no intention of doing?

Until the penny has dropped that decarbonisation without SRM is unacceptably risky, there'll be no progress on SRM safety and governance.

However, this merely shifts the problem back onto another problem.  How do you reach a rough global consensus on what an acceptable risk is?  That will be a tough assignment, but I can't see how the global community can come together to invest material and non-material assets in SRM until there's been some solid progress on addressing that question.

I am convinced that the foremost issue before us is to get people to grasp the scale of risk associated with decarbonisation alone.  (Decarbonisation is my shorthand for emissions reduction and GGR.)

Regards

RobertC

---

From: healthy-planet-...@googlegroups.com <healthy-planet-...@googlegroups.com> on behalf of Herb <hrb...@gmail.com>
Sent: Wednesday, October 15, 2025 23:05
To: Alan Kerstein <alan.k...@gmail.com>
Cc: Ron Baiman <rpba...@gmail.com>; rob...@rtulip.net <rob...@rtulip.net>; Tom Goreau <gor...@globalcoral.org>; Jan Umsonst <j.o.u...@gmail.com>; healthy-planet-action-coalition <healthy-planet-...@googlegroups.com>; William Beckler <bi...@bsec.org>; Aria Mckenna <ar...@globalcoolingproductions.com>; Cara Fleischer <ca...@creationcommunications.com>; Simmens Herb <hsim...@gmail.com>; Jake Schwartz <ja...@chesapeakeclimate.org>; Rafe Pomerance <rafe.po...@gmail.com>; Michael MacCracken <mmac...@comcast.net>; Climate Alliance Healthy <healthy-clim...@googlegroups.com>; Planetary Restoration <planetary-...@googlegroups.com>; Lucinda Shearman <lucindas...@hotmail.com>; Bruce Melton Austin Texas <bme...@earthlink.net>

Subject: Re: [prag] RE: [HPAC] How Climate Intervention can Safely and Quickly Cool the Planet_HPAC NYC Climate Week_Sep. 26, 2025

Alan,

I am puzzled about your statement that randomized  trials or digital twins are the only way to establish the safety of something that has not been done before. 

The US space program did something that was not done before - that’s for sure- and they incrementally tested in the lab, on the computer and ultimately in the field, and learned from each of those tests sufficient to conclude that it was safe enough - let’s leave aside the criteria needed to make that judgment - to proceed to the next test. 

This went on for close to a decade with as I recollect only one major and tragic mishap. The Apollo Project ultimately as we know succeeded in its mission to get to the moon within a decade without a randomized trial or a digital twin. 

So too could cooling interventions be scaled up if and when social permissions are available. There is of course little indication for or evidence of the necessary social acceptance in place to even begin the tiniest tiniest field tests as events in Alameda California, Mexico and Sweden have demonstrated. 

What is urgently required in my view is a global scale highly structured process to attempt however challenging it would be to achieve at least some rough consensus as to an operational definition and description of safety and effectiveness. 

This is where the necessary risk risk analysis would need to be undertaken and applied. 

Herb

Herb Simmens
Author of A Climate Vocabulary of the Future

“A SciencePoem and an Inspiration.” Kim Stanley Robinson
@herbsimmens
HerbSimmens.com

On Oct 15, 2025, at 5:27 PM, Alan Kerstein <alan.k...@gmail.com> wrote:



Thanks Robert, Herb, and Ron for your insightful comments. I like to think in terms of the Dyad, which is cooling plus all methods of reducing atmospheric GHG concentration (so GCR meaning greenhouse-gas concentration reduction), so I will reply in this framing. 

Robert, you express skepticism about a carbon tax from a political perspective but you express no concern about its intrinsic merits. Any GCR deployment at the needed scale will incur huge costs that will have to be borne by someone. Your concern about resistance to a carbon tax likewise applies to any conceivable method of picking Peter’s pocket to pay Paul the GCR deployer. In effect, you are pointing out a major barrier to any approach to financing GCR implementation.

Your point about this Robert, and Ron’s point about collective versus individual economic decision making, both reflect the underlying reality that GCR will require an unprecedented degree of action that contravenes individual preferences, or to put it plainly, coercion. So the challenge is to force billions of people to do things, or at least to acquiesce to things, that contravene their preferences.

I will summarize the requirements for successful GCR deployment in the following short list:

1. Capability to apply massive coercion without tearing society apart.

2. Capability to execute the mechanical, technological, and organizational aspects of GCR deployment at the needed scale.

3. Reality-based governance with long-term focus.

I have racked my brain to come up with a real-world example of the confluence of such capabilities in a single entity, and by a process of elimination the closest approximation is China. This leads me to the distasteful conclusion that any reorganization of global society for effective deployment of GCR should seek to emulate the Chinese model in terms of the listed attributes while minimizing the undesirable features that afflict the Chinese system. In this regard, I’m not optimistic that we can have our cake and eat it too, but if not, we might by default leave it in the hands of the Chinese leadership to set the terms of GCR deployment.

Herb, my reading of the mission statement gives me the impression that it is more prescriptive than your comments imply. In any case, this is just a minor quibble in the overall scheme of things.

I have more serious qualms about your statement “In addition any direct climate cooling interventions need to be shown to be safe and effective, characteristics that remain to be authoritatively confirmed.” There are only two ways to establish the safety and effectiveness of something that has never been done before - a randomized trial or a digital twin. The former does not apply and digital twins achieve the needed fidelity only for engineered systems that are designed to be mathematically representable with the needed precision.

Given the risk-vs.-risk perspective that seems to be a longstanding consensus within HPAC, the quoted statement surprises me. Reflecting that apparent consensus, I think that the best we can say given the uncertainties is that the heat stored in the atmosphere is the proximate and primary driver of the thermodynamic engine that causes harmful climate change, so the primary effect of expelling some of that heat is likely to be an overall reduction of climate harms. This does not preclude risky side effects. Indeed, the possibility that cooling will cause worse problems than it solves cannot be ruled out, but the overall balance of risks favors cooling.

I think that all public statements about cooling and GCR should be based on the unvarnished truth. There is a long history of policies that foundered partially due to well-intentioned trimming of the rough edges of the hard truth.

Alan

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[Robert Chris]

Further to my comments below, it occurs to me that HPAC focuses on the climate science, the technology and domestic and parochial policy and policymakers.  However, the word 'global' keeps popping up and as the UN, through its many agencies illustrates, there is the crucial dimension of international relations.

Over several centuries, we have created a deeply entrenched anarchic world order.  Sadly, we're living through a period right now when there is greater fragmentation driven by major powers seeking to consolidate and grow their economic and security interests.

This is not a backdrop that is conducive to collaboration. It doesn't prevent it, but it does make it much more challenging, and critically, slower to emerge.

It is this framing that underpins the comments I made earlier.

Regards

RobertC

---

From: Robert Chris <robert...@gmail.com>
Sent: Wednesday, October 15, 2025 23:24
To: Herb <hrb...@gmail.com>; Alan Kerstein <alan.k...@gmail.com>

[Ron Baiman]

Dear Colleagues,

Good discussion to which of course I can't help but add a few points!

First, I sympathize with Alan's concern over excessively absolute standards for governance before deployment in light of the risk-risk tradeoff that we are facing. My thinking is that,  per the governance discussion in the "challenges and opportunity" section  of the HPAC cooling paper (see: https://academic.oup.com/oocc/article/4/1/kgae014/7731760 ), in a situation where not deploying global cooling asap will without a doubt lead to greater warming and longer overshoot and thus greater calamity for humans and other living species, as in war war-time decision making, we need to have a more evolutionary symbiotic view of the relationship between governance and deployment (and governance and field testing) that specifically challenges the now dominant position stressing multiple absolute hurdles of social acceptance and governance that must be in place before piloting SAI or indeed even doing small-scale outdoor experiments with this in mind. Here's a powerpoint summarizing this view (that is in our paper) that I presented at an HPAC meeting some time ago: https://docs.google.com/presentation/d/1mQed7U89TEjOWi31rTGwaubg0vpk-SzK/edit?usp=sharing&ouid=116465941111195452408&rtpof=true&sd=true 

See also slide 9 of this (slightly updated - in red) powerpoint for my presentation of the Abstract that I, Mike and Greg submitted on behalf of the UR WG to SAI workshop: https://docs.google.com/presentation/d/1bNkZVjYBBS1ljhcY7RFVdnsikmjmCWw9/edit?usp=sharing&ouid=116465941111195452408&rtpof=true&sd=true

Second, relevant to this (and a point that I've been trying to convey in various fora) is Mike's recent observation (I think I'm correctly describing his thinking on this - and cc'ing him just in case!)  that as we know that SAI works (volcanoes have been doing it through geological history) and given the urgent need to cool, our focus should now be on "engineering optimization" that can only really only be done through piloting and real in-situ experimentation to reduce and (hopefully) work around known known possible adverse side effects (from modeling none are catastrophic) and possible unknown (from modeling) adverse impacts, and expand benefits as much as possible. This view I think makes clear that, though more research is always better, the priority now needs to be practical deployment focused testing and gradual scaling. 

Third, I am also sympathetic to Alan's reasoning with regard to China that (in a much more thought out and careful way) expands on discussions that I have had with regard to a geopolitical self-interest based SAI deployment that might be initiated by a political leadership with longer time horizons than are typical in a democracy. In this sense the issue is not only whether we can cool quickly but also whether the very hard fought and difficult to sustain accomplishment of democratic constitutional governance can survive this particular leadership and capacity test as it did the fight against facism.  

Finally, Herb and I have long disagreed over what can be considered (if anything) HPAC's official "mission statement". My reading is that HPAC now has in fact multiple different mission statements produced at different points in time for different purposes that broadly agree on promoting (differently nuanced versions) of the climate Triad as our core mission. 

Best,

Ron

On Wed, Oct 15, 2025 at 7:18 PM Alan Kerstein <alan.k...@gmail.com> wrote:

Herb,

The space program catastrophes were first, the fuel tank explosion upon takeoff and second, on a different mission, the detachment of heat-shield tiles resulting in the crash landing. The explosive failure of a valve during another mission caused a near catastrophe that was averted by means of an unlikely sequence of lucky breaks and brilliant improvisations.

This in fact proves the point that Murphy’s law applies even to the most meticulously designed and fabricated engineered system. There were no mission-critical unknowns about externalities such as atmospheric conditions, the environment in the vacuum of space, or the lunar surface. A digital twin of a space mission is likely infeasible even now, but if it were it might have identified the design, manufacturing, and operational deficiencies that caused at least some of the failures. Nevertheless, the Apollo Project was ultimately successful, as you note, despite its huge risks and consequent tragic failures along the way. This is a far different statement than claiming that the risks were reduced to negligible levels from the get-go. (I recognize that you are not claiming this.) Likewise, I believe that cooling deployment will ultimately succeed in delivering substantial net benefits despite significant likelihood of major unanticipated adverse side effects. Again, this is far different than expecting that such side effects can be anticipated and forestalled in advance with high confidence.

Admittedly, my point about random trials and digital twins was a red herring. No justification is needed for the self-evident assertion that the Earth-system response to a significant perturbation of radiative inflows and outflows is subject to major uncertainties that nothing short of full-scale implementation over an extended period can reliably resolve.

Your last two sentences are not inherently problematic, but I am concerned that some implicit if not explicit absolute standard of safety and effectiveness might emerge from the process that is impossible to satisfy, thereby superseding the risk-vs.-risk framing that is needed to achieve the best possible outcome.

Alan

P.S. to Robert C.: I wrote the above before your two most recent emails, which are largely consonant with my viewpoint. Regarding your question “Why bother …?” my answer is that contingency planning is a useful exercise that can help us to formulate a cohesive rationale for our position so that we are ready to step forward confidently when circumstances are conducive. This is the standard change-maker playbook (also would-be revolutionaries, demagogues, despots, etc.).

[Ron Baiman]

 Good point. In terms of an emergency risk-risk public decision. 

Sent from my iPhone

On Oct 16, 2025, at 8:42 PM, Alan Kerstein <alan.k...@gmail.com> wrote:



Ron,

Regarding war-time decision making, another relevant case is the emergency use authorization that expedited the distribution of covid vaccines. It was specifically a risk-vs.-risk judgment addressing the speed of deployment.

Alan

[David Price]



Hi RobertC

Some interesting questions there. I started responding a couple of days ago then got sidetracked.  Here are my 2 cents’ worth of a scenario.  I made no assumptions about SRM as you specifically did not include that in your “template”. Rather I assumed you were interested in assessing the sensitivity of climate to different emissions scenarios combined with different SRM options. 

annual CO2 emissions will reach 40 GtCO2 by 2035, then remain approximately level at 40 Gt until 2060. And then fall to 10 Gt by 2120. 

Note we are already close to 40 Gt CO2/yr and while I have great expectations for China’s progress, I expect in the short term, most other major emitting countries will negate any significant reductions achieved by China! 

Given the role of natural C sinks today, around 5-7 Gt CO2/yr, my projection would imply about 2000 Gt additional human-caused CO2 released by 2120, minus about 500-700 Gt biospheric uptake. This latter estimate is likely optimistic as many of the natural sinks are being compromised by human degradation and the ongoing effects of a warming climate (affecting forests and wetlands) while ocean acidification is likely to compromise precipitation of planktonic carbonates — but I’m no expert on ocean C dynamics. 

So perhaps we should expect biospheric removals of 500 Gt at most, by 2120, leaving at least 1500 Gt more CO2 in the atmosphere by 2120. This implies an increase of about 190 ppm from today — to reach around 610 ppm. (I was actually surprised when I worked this out, but I think I am correct within a few percent: please verify or otherwise.)

I imagine that if the human population survives that long in a reasonably coherent civilization, then FF GHG emissions will decline to around 1 Gt/yr after 2120, but I cannot guess whether that tail off will be rapid or slow, linear or exponential. There will also be “legacy CO2 emissions” from the oxidation/ degradation of plastics and other “long-lived” FF products like creosote and asphalt — and concrete — probably persisting for centuries. I cannot believe that while a human population persists, anthropogenic GHG emissions will ever be truly zero. It may be possible to produce food for ~9 billion people with a much smaller average C footprint than we have today, but i don’t think it will ever be possible to avoid some GHG emissions from agriculture. 

I do not see engineered CDR applied to atmospheric CO2 ever being a practical solution — because the energy inputs needed to remove CO2 at around 0.05% atmospheric concentration are just too huge to make it feasible at the scale needed to have a significant impact.  But if it could be implemented successfully to remove all CO2 from all industrial emission sources “at the flue”,  that would make a dent in my projections.

Sticking my neck out here: My expectation for CO2 concentration in the long term has always been that it will persist at somewhere around the maximum (let’s assume 600 ppm) probably for centuries. In the short term we can expect it to continue to rise a bit as the biosphere gradually equilibrates to a warmer global climate   But, optimistically, CO2 will peak and then drop a few ppm over several decades, as the equilibrating natural C sinks reorganize to generally higher latitudes and higher altitudes in a warmer world with a CO2-enriched atmosphere. Possibly human actions will accelerate that biospheric equilibration process. But after that, the natural C sinks will become saturated, and their capacity to continue removing CO2 will be limited — probably around 5 Gt per year at best. Theoretically this means we could expect CO2 to decrease initially at around 0.5 to 0.7 ppm per year…I think in practice this rate of removal by natural C sinks is also probably overly optimistic, but I don’t really know why! (But see concerns about compromised C sinks above!) 

For sure as the concentration drops, the rate of net CO2 removal will gradually tend to zero. If we assume a linear rate of decrease, that suggests (back-of-envelope estimate!) at least 1000 years to get back to pre-industrial, but rather less to get down to 350. With a more realistic asymptotic decrease, both targets will take longer.  

David 

From my cellphone

I acknowledge that I reside on unceded Traditional Territory of the Secwépemc People

On Oct 12, 2025, at 9:48 am, Robert Chris <robert...@gmail.com> wrote:



Hi RobertT (and everyone)

I am putting the finishing touches to my adaptation of the FaIR climate model.  In this endeavour I'd like to test it with your views of the plausible future trajectory for CO2 emissions, CO2 drawdown through CDR and deployments of SRM.  The model runs out to 2300, so if you could give me your thoughts on a range of likely outcomes for those three variables it would be really helpful.

The model is agnostic about the source of the emissions, CDR and SRM.

The way the model handles the data is a milestone value by a certain year.  There are three milestone for each variable.  The simple way to provide the inputs values is to fill in the blanks in the following:

annual CO2 emissions will reach XGtCO2 by 2XXX, then increase/fall to YGt by 2XXX. And then rise/fall to ZGt by 2XXX, where the years lie between 2025 and 2300.  No need to specify all three X, Y and Z, you might think, for example, that emissions will rise to 50GtCO2/yr by 2050 and then slowly decline to an irreducible minimum of 10GtCO2/yr by 2200.

CDR and SRM are defined in the same way, save that they both have a start year that needs to be specified and SRM is measured in Wm^-2.

If others want to send me your views on how emissions, CDR and SRM might play out, or if you're just interested to know what the surface temperature impact is of any particular combination of all three, just let me have your numbers.

The purpose of this exercise is to provide a quick and reliable sense of the plausibility and outcome of the many options open to policymakers.

Regards

RobertC

---

From: healthy-planet-...@googlegroups.com <healthy-planet-...@googlegroups.com> on behalf of rob...@rtulip.net <rob...@rtulip.net>

Sent: Sunday, October 12, 2025 04:12

To: 'Tom Goreau' <gor...@globalcoral.org>; 'Jan Umsonst' <j.o.u...@gmail.com>; 'Ron Baiman' <rpba...@gmail.com>

Cc: 'healthy-planet-action-coalition' <healthy-planet-...@googlegroups.com>; 'William Beckler' <bi...@bsec.org>; 'Aria Mckenna' <ar...@globalcoolingproductions.com>; 'Cara Fleischer' <ca...@creationcommunications.com>; 'Herb Simmens' <hsim...@gmail.com>; 'Jake Schwartz' <ja...@chesapeakeclimate.org>; 'Rafe Pomerance' <rafe.po...@gmail.com>; 'Michael MacCracken' <mmac...@comcast.net>; 'Healthy Climate Alliance' <healthy-clim...@googlegroups.com>; 'Planetary Restoration' <planetary-...@googlegroups.com>; 'Lucinda Shearman' <lucindas...@hotmail.com>; 'Bruce Melton -- Austin, Texas' <bme...@earthlink.net>

Subject: RE: [prag] RE: [HPAC] How Climate Intervention can Safely and Quickly Cool the Planet_HPAC NYC Climate Week_Sep. 26, 2025

To view this discussion visit https://groups.google.com/d/msgid/healthy-planet-action-coalition/VI1P194MB03986AB8C29E8157CF46D4FCFCEDA%40VI1P194MB0398.EURP194.PROD.OUTLOOK.COM.

[Alan Kerstein]

Thanks Robert, Herb, and Ron for your insightful comments. I like to think in terms of the Dyad, which is cooling plus all methods of reducing atmospheric GHG concentration (so GCR meaning greenhouse-gas concentration reduction), so I will reply in this framing. 

Robert, you express skepticism about a carbon tax from a political perspective but you express no concern about its intrinsic merits. Any GCR deployment at the needed scale will incur huge costs that will have to be borne by someone. Your concern about resistance to a carbon tax likewise applies to any conceivable method of picking Peter’s pocket to pay Paul the GCR deployer. In effect, you are pointing out a major barrier to any approach to financing GCR implementation.

Your point about this Robert, and Ron’s point about collective versus individual economic decision making, both reflect the underlying reality that GCR will require an unprecedented degree of action that contravenes individual preferences, or to put it plainly, coercion. So the challenge is to force billions of people to do things, or at least to acquiesce to things, that contravene their preferences.

I will summarize the requirements for successful GCR deployment in the following short list:

1. Capability to apply massive coercion without tearing society apart.

2. Capability to execute the mechanical, technological, and organizational aspects of GCR deployment at the needed scale.

3. Reality-based governance with long-term focus.

I have racked my brain to come up with a real-world example of the confluence of such capabilities in a single entity, and by a process of elimination the closest approximation is China. This leads me to the distasteful conclusion that any reorganization of global society for effective deployment of GCR should seek to emulate the Chinese model in terms of the listed attributes while minimizing the undesirable features that afflict the Chinese system. In this regard, I’m not optimistic that we can have our cake and eat it too, but if not, we might by default leave it in the hands of the Chinese leadership to set the terms of GCR deployment.

Herb, my reading of the mission statement gives me the impression that it is more prescriptive than your comments imply. In any case, this is just a minor quibble in the overall scheme of things.

I have more serious qualms about your statement “In addition any direct climate cooling interventions need to be shown to be safe and effective, characteristics that remain to be authoritatively confirmed.” There are only two ways to establish the safety and effectiveness of something that has never been done before - a randomized trial or a digital twin. The former does not apply and digital twins achieve the needed fidelity only for engineered systems that are designed to be mathematically representable with the needed precision.

Given the risk-vs.-risk perspective that seems to be a longstanding consensus within HPAC, the quoted statement surprises me. Reflecting that apparent consensus, I think that the best we can say given the uncertainties is that the heat stored in the atmosphere is the proximate and primary driver of the thermodynamic engine that causes harmful climate change, so the primary effect of expelling some of that heat is likely to be an overall reduction of climate harms. This does not preclude risky side effects. Indeed, the possibility that cooling will cause worse problems than it solves cannot be ruled out, but the overall balance of risks favors cooling.

I think that all public statements about cooling and GCR should be based on the unvarnished truth. There is a long history of policies that foundered partially due to well-intentioned trimming of the rough edges of the hard truth.

Alan

On Wed, Oct 15, 2025 at 12:10 PM Ron Baiman <rpba...@gmail.com> wrote:

[Herb]

Alan,

I am puzzled about your statement that randomized  trials or digital twins are the only way to establish the safety of something that has not been done before. 

The US space program did something that was not done before - that’s for sure- and they incrementally tested in the lab, on the computer and ultimately in the field, and learned from each of those tests sufficient to conclude that it was safe enough - let’s leave aside the criteria needed to make that judgment - to proceed to the next test. 

This went on for close to a decade with as I recollect only one major and tragic mishap. The Apollo Project ultimately as we know succeeded in its mission to get to the moon within a decade without a randomized trial or a digital twin. 

So too could cooling interventions be scaled up if and when social permissions are available. There is of course little indication for or evidence of the necessary social acceptance in place to even begin the tiniest tiniest field tests as events in Alameda California, Mexico and Sweden have demonstrated. 

What is urgently required in my view is a global scale highly structured process to attempt however challenging it would be to achieve at least some rough consensus as to an operational definition and description of safety and effectiveness. 

This is where the necessary risk risk analysis would need to be undertaken and applied. 

Herb

Herb Simmens
Author of A Climate Vocabulary of the Future

“A SciencePoem and an Inspiration.” Kim Stanley Robinson
@herbsimmens
HerbSimmens.com

On Oct 15, 2025, at 5:27 PM, Alan Kerstein <alan.k...@gmail.com> wrote:



Thanks Robert, Herb, and Ron for your insightful comments. I like to think in terms of the Dyad, which is cooling plus all methods of reducing atmospheric GHG concentration (so GCR meaning greenhouse-gas concentration reduction), so I will reply in this framing. 

To view this discussion visit https://groups.google.com/d/msgid/healthy-planet-action-coalition/CAH-gPYHbGq06kUORuXA70VhXdOJ%2Baf-X-Z5OZuEtQBJ9d76t5w%40mail.gmail.com.

[Alan Kerstein]

Herb,

The space program catastrophes were first, the fuel tank explosion upon takeoff and second, on a different mission, the detachment of heat-shield tiles resulting in the crash landing. The explosive failure of a valve during another mission caused a near catastrophe that was averted by means of an unlikely sequence of lucky breaks and brilliant improvisations.

This in fact proves the point that Murphy’s law applies even to the most meticulously designed and fabricated engineered system. There were no mission-critical unknowns about externalities such as atmospheric conditions, the environment in the vacuum of space, or the lunar surface. A digital twin of a space mission is likely infeasible even now, but if it were it might have identified the design, manufacturing, and operational deficiencies that caused at least some of the failures. Nevertheless, the Apollo Project was ultimately successful, as you note, despite its huge risks and consequent tragic failures along the way. This is a far different statement than claiming that the risks were reduced to negligible levels from the get-go. (I recognize that you are not claiming this.) Likewise, I believe that cooling deployment will ultimately succeed in delivering substantial net benefits despite significant likelihood of major unanticipated adverse side effects. Again, this is far different than expecting that such side effects can be anticipated and forestalled in advance with high confidence.

Admittedly, my point about random trials and digital twins was a red herring. No justification is needed for the self-evident assertion that the Earth-system response to a significant perturbation of radiative inflows and outflows is subject to major uncertainties that nothing short of full-scale implementation over an extended period can reliably resolve.

Your last two sentences are not inherently problematic, but I am concerned that some implicit if not explicit absolute standard of safety and effectiveness might emerge from the process that is impossible to satisfy, thereby superseding the risk-vs.-risk framing that is needed to achieve the best possible outcome.

Alan

P.S. to Robert C.: I wrote the above before your two most recent emails, which are largely consonant with my viewpoint. Regarding your question “Why bother …?” my answer is that contingency planning is a useful exercise that can help us to formulate a cohesive rationale for our position so that we are ready to step forward confidently when circumstances are conducive. This is the standard change-maker playbook (also would-be revolutionaries, demagogues, despots, etc.).

On Wed, Oct 15, 2025 at 3:39 PM Robert Chris <robert...@gmail.com> wrote:

[Alan Kerstein]

Ron,

Regarding war-time decision making, another relevant case is the emergency use authorization that expedited the distribution of covid vaccines. It was specifically a risk-vs.-risk judgment addressing the speed of deployment.

Alan

[Ron Baiman]

Dear Colleagues,

Just to reinforce the final point in my last Oct. 15 post to this thread, here's the description of HPAC on our YouTube channel (where our "star" - David Spratt - recording has received almost 200 views): 

Healthy Planet Action Coalition

Description Founded in 2021, the Healthy Planet Action Coalition (HPAC) is an international group of over 200 members from over a dozen countries advocating a "climate triad" for a safe and healthy planet for humans and other species (Baiman et al. 2024. Oxford Open Climate Change 4(1): https://academic.oup.com/oocc/article/4/1/kgae014/7731760): "On a global scale, restoring the relatively beneficial climatic conditions of the 20th Century will require a restoration plan to return global warming to well below 1°C. To be effective, such a plan would need to include: (i) researching, field testing, and deploying one or more large-scale cooling influence(s) perhaps initially in polar regions and applying local and regional cooling measures that also support adaptation, (ii) accelerating emissions reductions with an early prioritization of short-lived climate-drivers, and, (iii) deploying large scale carbon removal to draw down legacy greenhouse gas." www.healthyplanetaction.org

Best,

Ron