Termination shock analysis

[H simmens]

Can someone provide a reference to an authoritative paper or article that analyzes the risk of termination shock. 

Thanks

Herb

Herb Simmens
Author of A Climate Vocabulary of the Future

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

[Robert Chris]

Herb

All anyone needs to know about termination shock is that it only arises in very specific circumstances that are very unlikely to arise.  Two conditions both have to apply.

First, the risk of termination increases with the amount of warming suppressed by SAI.  That is why recourse to SAI must not reduce commitment to decarbonise.

Second, the risk of termination shock, however great the suppressed warming, only arises if there is a sudden cessation of the SRM.  In this event the suppressed warming would emerge over a couple of decades.

In effect, termination shock requires many decades of at scale SRM accompanied by weak or negative decarbonisation, and for its deployment to be abruptly stopped.

Clearly, these conditions are plausible.  But they can't arise for many decades to come, and we'd have to assume that those then in power would be ignorant and/or stupid enough to allow the termaination shock to happen.

If we claim that they might be that ignorant and/or stupid and as a result we do not deploy SRM at scale in circumstances where our successors have been equally as ignorant and/or stupid not to aggressively decarbonise, the warming will get them before the termination shock does.

Not doing SRM is an example of the 'dangerous precedent', once described as obliging one not to do what you know to be right, for fear that your successors might be too timid to do likewise.

In sum, not doing SRM for fear of termination shock is a lose/lose choice.  We'd have to be as ignorant and/or stupid as we would be assuming our successors will be.

Termination shock is ike moral hazard, everyone writes a lot about them and they're raised as big issues and obstacles.  They're both theoretical possibilities that are extremely unlikely to arise in practice simply because they are both anchored in a cynical view about human wisdom.  We are not ignorant and/or stupid, and despite all our mistakes and follies, most of the time we get things more or less right.

Is that authoritative enough for you?  😆

Regards

RobertC

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From: healthy-planet-...@googlegroups.com <healthy-planet-...@googlegroups.com> on behalf of H simmens <hsim...@gmail.com>
Sent: 27 October 2025 15:44
To: healthy-planet-action-coalition <healthy-planet-...@googlegroups.com>
Subject: [HPAC] Termination shock analysis

 

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[H simmens]

Hi Robert,

Your narrative is persuasive enough but it is inherently not authoritative enough. 

I’m engaged in a dialogue with a well known Climate author who is knowledgeable yet adamantly against SRM. I want to be able to send him /her an article - preferably peer reviewed- by someone who is recognized as an expert. 

Herb 

Herb Simmens
Author of A Climate Vocabulary of the Future

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

On Oct 27, 2025, at 12:10 PM, Robert Chris <robert...@gmail.com> wrote:

[Robert Chris]

Here's the first one (attachments not in same order as my comments). 

Malm is VERY anti-SAI.  But his argument perfectly illustrates the points I was making.  Here a brief extract:

Imagine it is the year 2130 and the operation has been going on for a century. In the meantime, fossil fuel combustion has not ceased.

He assumes that we'd get to 2130 untroubled by the unmitigated warming up until then.  A typical one-sided argument that presumes there's no risk associated with the no-SRM status quo.

He also completely ignores the possibility, even the likelihood, that alternatives to SO2 might be found, that deployment strategies might be developed, that decarbonisation might be delivered, and so on.

He also has no idea how much the suppressed warming might be in 2130.  My model tells me that in the scenario he posits it would be about 1C by then, depending upon the deployment strategy adopted.  The unmitigated warming would be almost 3C by then.

He then says:

If, come 2130, emissions have not only been reduced to zero, but carbon dioxide removal has also cleaned the atmosphere of the historical accumulation and returned the co2 concentration to, say, 350 ppm, termination would not set off any roasting. If the net sum – behind the frail engineered glass door – is rather a doubling or quadrupling of that concentration, the result could be exceedingly cataclysmic. It follows that inasmuch as geoengineering exerts an effective temptation upon capitalist society to keep business-as-usual in place, the risk of a severe termination shock rises. (emphasis in original)

But in the first scenario he posits here, there would be no need for any SRM, and in the second, we'd be so totally fucked without the SRM, that it beggars belief that he could argue that not having it would be a wise response to our predicament.

The rest is a Marxist anti-capitalist rant.  Just because Malm is an Assoociate Professor in 'Human Geography', doesn't make him an authority on climate science.

The next is David Keith examining concerns about SAI, including termination shock.  He does his usual calm and rational analysis, trying hard not to overstae his case.

Next up is Holly Buck.  Here's an extract from her paper:

Risks and harms: the stopgap poses several types of direct  risks, including ozone depletion34, cirrus cloud interactions35, suppression of the hydrological cycle36, effects of increased diffuse sunlight37 and termination shock in the case of poor implementation38. The severity of these risks is highly uncertain and represents a clear research priority. Indirect risks are hard to quantify; many of them inhere in the details of the chosen stratospheric aerosol deployment scheme and how it is implemented39. Risk assessment must also take into account the counterfactual climate change scenario.

She's making clear that the risks are recognised, that they require further research, but there is nothing inherently certain about the harms the SAI might cause to enable a safe conclusion that there are no cicustances in which it would b better to do it than not.

Another extract from Keith being interviewed:

David Keith: I personally do not see [temination shock] as a risk in the same categories as others. So first of all, it’s certainly true that we will discover new surprises and new bad outcomes. And that may cause people to change how much they’re doing or to transition from one kind of solar geoengineering to another. But I think the risk of very sudden turn off of large-scale solar geoengineering is pretty low because of individual country level selfinterest. Even countries that initially opposed deployment of solar geoengineering have a very strong self interest in maintaining the ability to start it once deployed because of the risks of sudden termination. And sudden termination effectively requires unanimity, global unanimity among countries of significant scale, in shutting it off. And I think that’s a very unlikely outcome.

Parson writes:

Other studies suggest that risks of termination shock (Parker & Irvine, 2018; Rabitz, 2019) and geopolitical conflict (Heyen et al., 2019) may be overstated or mitigable.

Those authorities can easily be referred to; Parker & Irvine attached here.

Then there's me.  I've also attached a note I wrote this time last year.  Not published nor peer reviewed. 

And I leave the best til last.  here's the Andy Parker/Pete Irvine contribution referred to by others.

I have more!

Regards

Robert

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From: Robert Chris <robert...@gmail.com>
Sent: 27 October 2025 16:48
To: H simmens <hsim...@gmail.com>
Subject: Re: [HPAC] Termination shock analysis

 

Let me see what I've got in my archive.

Regards

Robert

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From: H simmens <hsim...@gmail.com>
Sent: 27 October 2025 16:28
To: Chris Robert <robert...@gmail.com>
Cc: healthy-planet-action-coalition <healthy-planet-...@googlegroups.com>
Subject: Re: [HPAC] Termination shock analysis

 

[John Nissen]

Hi Herb,

Robert Chris is absolutely correct on the physics and my confidence arises from the original paper by Caldeira and Matthews on the subject and the irrefutable logic. Most importantly there is not a jump in temperature but a jump in the rate of temperature rise since climate forcing has just jumped up.

Those who are scared of SRM will grasp any straws to argue that it's too risky. Perhaps there should be a well-funded campaign to rehabilitate SRM and counter decades of bad publicity, even continued in the latest New Scientist.  If Rob T idea of an albedo accord materialises, rehabilitation should be part of its remit.

Cheers John 

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