Guardian article 19 June 2026
Robert Chris
I sent the letter below to the Guardian in response to last week's article on SRM by Pierrehumbert, Slingo, Mann and Masson-Delmotte . Don't expect it to be published, not least because it's a bit too long.
RobertC
Dear Editor
Re: ‘Termination shock’: trust our expert warnings on geoengineering’s planetary risks 19 June 2026
It is extraordinary that there are prominent climate scientists in denial about the extent and imminence of the risks from climate change. Pierrehumbert, Mann, Slingo and Masson-Delmotte are amongst them. Their focus on the risks of geoengineering, apparently totally unconcerned about the parallel risks from not geoengineering, is mind-boggling. There is no argument that geoengineering is risky. But how risky it is in comparison to the alternatives is a critical question they seem happy to ignore. No tourniquets for them, they might cause gangrene. No pain-relieving medicines or chemotherapy for them, they might have side effects. No emergency braking for them, they might hit their heads on the windscreen.
The starting point for any conversation about intervening to reduce the amount of solar radiation absorbed by Earth’s climate system, which is what the solar radiation modification (SRM) version of geoengineering is intended to do, is what happens if we don’t. Modelling evidence is clear: not reducing absorbed solar radiation is a very high-risk strategy. This crew claim that ‘when you’re in a climate hole, stop digging … and burning fossil fuels. It really is … that simple’. Given that between them they claim to ‘have studied the physics of climate for the equivalent of well over 100 years’ it beggars belief that they are unaware or perhaps merely unconcerned by the robust modelling evidence that there is no longer any plausible future emissions scenario that will prevent global mean surface temperature from rising more than enough to risk widespread societal and ecosystem collapse in the coming decades. That train left the station some time ago. The only trains left are slow ones and if we want high confidence they’ll reach their destination in time to deliver us from climate catastrophe, they need boosters. That’s how to frame SRM; it’s a booster not an alternative. No one promoting SRM claims it’s an alternative to aggressive emissions reductions.
Is a climate change induced collapse certain? Certainly not. But it is certainly plausible. And here we come to the nub of the problem. For climate scientists, risk derives from ignorance. Their response is to do more research. That’s what scientists do, they research. But they don’t act because in complex adaptive systems like Earth’s climate system, there is no stopping point when they can declare that we finally know with high confidence that if we do this, then the result will be that. In part, there is no stopping point because they can never know how future people will behave. Will we reach net zero emissions by 2050 or might it be 2150, or even 2250? This is unknowable and because it’s unknowable they dream up sets of different future scenarios and say that in this scenario, that would happen and in a different scenario something else would happen. But which scenario will be closest to future reality, they have as much idea as the rest of us. This is the academic job preservation plan – more research keeps them employed.
However, more research generally increases risk where it is used as an excuse to not act. Throughout human history we have learnt by doing. The Danyang–Kunshan Grand Bridge in China, the world’s longest bridge, was not the first bridge ever built. The Airbus A350 was not the first machine to take to the skies. We have thousands of years of experience of learning by doing. There is no reason to suppose that technologies to reduce the amount of absorbed solar radiation will be any different. Will they be risk free? Certainly not. But will they be risk reducing, almost certainly because we’ve quite a good record of screening out the trials that fail before they cause too much harm.
But we can be confident that without these technologies the likelihood of catastrophic warming is increased to the point of being very likely. The public and our politicians have a simple choice. Rely on the advice of a small cadre of climate scientists who by their utterings demonstrate that they do not understand how to respond effectively to avert existential risk, or turn to those with experience in assessing real world risks and how to reduce them by the intelligent application of learning by doing.
As to the ‘termination shock’ that features so prominently in their title but receives only a cursory mention in the article, they fail to note that this would only be a significant threat in circumstances where several degrees of cooling were being delivered by the SRM. In this event, the collapse of civilisation as we know it (COCAWKI) would likely already have occurred had the SRM not been there to keep a lid on the warming. To argue, as many do, that the mere existence of SRM would exacerbate the underlying warming by taking the pressure off the need to phase out fossil fuels, what is often misleadingly referred to as ‘moral hazard’, is, in effect, to claim that we have no agency over our communal behaviours. If that’s so, why would fossil fuels be retired even in the absence of SRM? Maybe they won’t be. Certainly, in this regard we’ve not done a brilliant job so far; despite recent stunning growth in renewable energy, fossil fuels still account for close to 80% of global energy supply, a proportion that has hardly changed for decades.
If you’re under 50 you should take this issue very seriously. The accelerating pace of climate change and the lead times to scale the necessary climate interventions to avert COCAWKI mean that the time to act is now.
Dr. Robert Chris
Associate of the Centre for Climate Repair at Cambridge and a Visiting Fellow at The Open University.
Author of Systems Thinking for Geoengineering Policy: How to reduce the threat of dangerous climate change by embracing uncertainty and failure Earthscan 2015
Michael MacCracken
Hi Robert--Excellent. That article really did need a response and you did a fast and excellent job. The whole thing should be published, there or elsewhere and I'd be happy to recommend it if there is a way to do so.
Best, Mike
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Tim Foresman
Sent: Tuesday, June 23, 2026 1:12 PM
To: Robert Chris <robert...@gmail.com>; healthy-planet-action-coalition <healthy-planet-...@googlegroups.com>
Subject: Re: [HPAC] Guardian article 19 June 2026
Michael MacCracken
Hi Tim and Robert et al.--Just a note that just over a year ago after Raymond Pierrehumbert had an op-ed in the Guardian voicing his position, reporter Nick Breeze interviewed him and then wrote me a note about doing a followup interview (see inserted note below), which I did a few weeks later. My interview was/is posted at https://www.youtube.com/watch?v=_hc9X2x2LnI . Perhaps Robert C should contact Nick Breeze and do the followup this time--though would like The Guardian to also publish the response.
On why the particular scientists all are doing this now, I don't understand--perhaps all the additional discussion of the need for SRM but not, as far as I know, after doing a comparative risk analysis. As Robert C notes, Termination Shock, were it to happen, would only be significant if emissions reduction is not successful and if that is the case, then without SRM we'd have earlier had climate catastrophe.
Best, Mike
Insert of message from Nick Breeze, with contact info:
Tim Foresman
Sent: Tuesday, June 23, 2026 1:43 PM
To: Tim Foresman <fore...@earthparty.org>; Robert Chris <robert...@gmail.com>; healthy-planet-action-coalition <healthy-planet-...@googlegroups.com>
Ron Baiman
H simmens
Herb Simmens
Author of A Climate Vocabulary of the Future
“A wonderful achievement, a SciencePoem, an Inspiration, a Prophecy, also hilarious, Dive in and see"
Kim Stanley Robinson
@herbsimmens
Tim Foresman
Sent: Tuesday, June 23, 2026 2:41 PM
To: Tim Foresman <fore...@earthparty.org>
Cc: Chris Robert <robert...@gmail.com>; healthy-planet-action-coalition <healthy-planet-...@googlegroups.com>; Michael MacCracken <mmac...@comcast.net>
Alan Kerstein
Robert Chris
OMG! Thank you all for those remarkably positive comments. Several of you have made suggestions about how the letter might get wider distribution. This is not part of my skill set but I'd be very happy to respond positively to any initiatives any of you might care to explore in this regard.
Thanks, again.
RobertC
Douglas Grandt
 | |
On Jun 23, 2026, at 12:53 PM, Robert Chris <robert...@gmail.com> wrote:
Chris Robert
Hi Doug
Thanks for that. Good constructive criticism. I'm just finishing a 300 word version. It omits the 'job preservation' comment and the reference to COCAWKI. The reference to bridges and planes is much reduced. I'll circulate it shortly.
Robert