Perilously close to point of no return: the Arctic time bomb

[John Nissen]

Hi all,

Paul Gambill has been discussing the distinction between adaptation and geoengineering.  He argues for a risk-risk framework: comparing the risks of geoengineering with not geoengineering.  We agree whole-heartedly.  And we need to make it clear that the risks are not just quantitatively different, but also qualitatively different.

Carlos Nobre was quoted in a Guardian headline that "We are perilously close to a point of no return" on Amazon rainforest's future [1].  Could we achieve a similar headline quote for the five tipping points I've mentioned in our Arctic Emergency Report Card?  A point of no return is something the layman and the politician can understand.  

The imminent and extreme danger from tipping elements is that we may already have left it too late: not just perilously close.  Here's why.  The Arctic tipping elements are like time-bombs which share a common fuse: temperature rise.  If the Arctic temperature can be brought down, there is a chance to defuse the bombs. The time-bomb again is something people can understand.  Defusing is something which is obviously urgent.  Should we use this analogy in our report card?

The engineering problem is to lower the temperature, which is rising steeply and liable to rise even more steeply in the future.  Lowering the temperature requires a quick techno-fix: a measure which can be applied at the necessary scale very quickly: SAI.  We could call it protecting the Arctic; but it is protecting the future of humanity.  Rapid SAI deployment is a moral imperative.

The risk from the defuse action is not only of a different order of magnitude from the risk of the bomb exploding, but of a different quality.  Like the difference between the risk of damage from a fire-engine compared to the risk of the building burning down.  Parochial versus existential.

To hark back to today's Reith lecture, we need people with power, money and influence to use their position for the common good rather than selfish ends.  The small group of us, who understand what is at stake and what has to be done about it, need as much help as we can get.  Please reach out.

Our quest is firstly to save humanity from catastrophic climate change and sea level rise. and secondly to reverse climate change, slow sea level rise and ensure a flourishing future for humankind.  

Cheers, John

[1] https://www.theguardian.com/environment/ng-interactive/2025/jun/26/tippping-points-amazon-rainforest-climate-scientist-carlos-nobre

[John Nissen]

Hi all,

We could reach out to Bill Gates: off MCB and onto SAI it seems.  This is what Michael Mann (vehemently anti-geoengineering) has said in The Bulletin of Atomic Scientists (also anti-geoengineering):

https://thebulletin.org/2025/10/you-cant-reboot-the-planet-if-you-crash-it/#post-heading 

[Quote]

Most troublingly, Gates has peddled a planetary “patch” for the climate crisis. He has financed for-profit schemes to implement geoengineering interventions that involve spraying massive amounts of sulfur dioxide into the stratosphere to block out sunlight and cool the planet. What could possibly go wrong? And hey, if we screw up this planet, we’ll just geoengineer Mars. Right Elon?

[End quote]

Does anyone know about Gates' plan or how to get hold of his attention with ours?

Cheers, John

[rob...@rtulip.net]

Hi John

Thanks for sharing Mann’s attack piece on Bill Gates in the Bulletin of the Atomic Scientists. I remain deeply concerned by Michael Mann’s refusal to engage seriously with scientific information about the feasibility of rival climate policies. His article contains serious errors and misleading claims.

A few key points:

“if your only tool is technology, every problem appears to have a technofix.”

The thrust of this argument is that solar geoengineering is not needed. That ignores findings – referenced in his own paper - that albedo loss is now contributing more to the acceleration of warming than the greenhouse effect from new emissions.  The only way to restore planetary albedo is through technology. Planetary darkening cannot be slowed by carbon action. In effect, Mann is saying we must do nothing about planetary albedo.  Mann’s rhetoric slides from the true point that technology cannot fix all ills to the false claim that cooling technology is not necessary. He treats efforts to develop sunlight-reflection tools as misconceived, when in reality we face a risk–risk trade-off.  It is not a choice between a safe option (decarbonisation) and a reckless one (geoengineering). 

On the albedo-carbon comparison, CERES satellite data from NASA shows that since 2000, planetary darkening has increased absorbed solar radiation by 0.8–1.0 W/m².  That is up to 60% more than the extra greenhouse forcing from new emissions over the same period (≈0.6–0.8 W/m²).  That justifies the view that albedo is a more serious climate problem than new emissions.

“a major new climate report (disclaimer: I was a co-author) entitled “A Planet On The Brink” was published… The legacy media is apparently more interested in the climate musings of an erstwhile PC mogul than a sober assessment by the world’s leading climate scientists.”

A Planet on the Brink is not a neutral “sober assessment.” It doubles down on the familiar line that we must rapidly decarbonise, while saying almost nothing about the tools needed to manage the planetary energy imbalance on timescales that matter.  If media are cool towards this style of messaging, one possible reason is that it is heard as yet another demand for revolutionary economic restructuring with no credible back-up plan or transition strategy.  Especially when set against the UN’s 2021 call to halve global emissions by 2030, which is broadly see as politically and practically impossible.  Mann’s report does acknowledge that “warming may be accelerating, likely driven by reduced aerosol cooling, strong cloud feedbacks, and a darkening planet.”  But it fails to follow through on that unduly caveated admission by treating albedo restoration as an urgent climate task.

“modular nuclear reactors that couldn’t possibly be scaled up over the time frame in which the world must transition off fossil fuels.”

And he thinks decarbonisation can rapidly achieve climate relevant scale? Mann asserts that “the world must transition off fossil fuels” within a very tight timeframe – while providing no account of what happens when we inevitably don’t. That is a key reason for geoengineering.  There is no evidence-based pathway in which fossil fuel use vanishes fast enough to avoid dangerous warming without direct climate cooling.  We also need a lot more energy, including nuclear, ocean thermal and other low-emission firm sources. Dismissing options like advanced modular nuclear on ideological grounds leaves us with an energy system that is fragile, expensive, politically brittle and highly unsafe in the context of worsening climate change. 

“Gates … has financed for-profit schemes to implement geoengineering interventions that involve spraying massive amounts of sulfur dioxide into the stratosphere to block out sunlight and cool the planet.”

This claim about Bill Gates is factually wrong and should be corrected if the Bulletin wants to be seen as a trusted forum on planetary-scale interventions.  Gates has funded preliminary scientific research on solar geoengineering through philanthropic donations (e.g. FICER, Harvard’s Solar Geoengineering Research Program, the proposed SCoPEx experiment).  These projects do not aim at commercial deployment as Mann wrongly suggests.  SCoPEx proposed releasing a few kilograms of calcium carbonate, not “massive amounts of sulfur dioxide,” and has not proceeded. Fact-checkers have found claims that “Bill Gates is spraying the sky / blocking the sun” to be false and conspiratorial. Gates funds research, not large-scale or pilot deployment of stratospheric SO₂ injection. Mann’s claims do not match what Gates has actually funded.

“technofixes for the climate, in fact, lead us down a dangerous road, both because they displace far safer and more reliable options—namely the clean energy transition—and because they provide an excuse for business-as-usual burning of fossil fuels.”

Here again, Mann wrongly frames the choice as if we have a safe, reliable path (clean energy) and a dangerous one (sunlight reflection). My view is that treating clean energy as a primary climate strategy is a major security threat, bound to fail, and so highly unsafe and unreliable.  Emissions and temperatures are still rising, destabilising key tipping elements. Betting everything on emissions reduction alone while refusing to develop sunlight-reflection technologies is delusional.  Recent work on the planetary energy imbalance shows that albedo loss is now a major driver of warming. Treating albedo as off-limits is not caution, it is a refusal to engage on climate science.  The hope that nonlinear feedbacks will stay within manageable bounds leaves the world without any ability to reflect incoming sunlight and fails the precautionary principle.  On Mann’s ‘excuse’ claim, the moral-hazard literature around geoengineering is highly partisan. It does not justify the claim that sunlight reflection is more dangerous than decarbonisation. Its claim that banning SRM would somehow enhance political will for emissions cuts is little more than political cover for renewable energy subsidies. Fossil-fuel demand is driven by entrenched economic interests, not by hypothetical SRM projects. 

“The only safe and reliable way out when you find yourself in a climate hole is to stop digging—and burning—fossil fuels.”

This “law of holes” metaphor is wrong.  In a medical emergency, the priority is not to tweak your long-term lifestyle, it is to stabilise the patient. Likewise, in the current climate emergency, reducing actions that gradually worsen the problem (cutting emissions) is useful, but not sufficient. We also have to correct the acute radiative imbalance that is driving extreme weather and risks of systemic disruption.  The real “hole” we are now in is the entrenched belief that renewable energy transition is the primary climate solution. There are strong commercial and ideological interests in continuing to dig that hole. Calling a combustion ban “the only safe and reliable way” without any back-up plan for cooling is dangerous rhetoric, not risk management.

Mann says “Gates does an injustice to the very dramatic inroads that renewable energy and energy efficiency are making…”. He refers to studies claiming “very credible” pathways to 100 percent non-carbon energy by 2050 that are “easily scalable”.  He asserts “the obstacles aren’t technological. They’re political.”

These pathway studies are disputed. “100% renewables by 2050” roadmaps are criticised by energy-system modellers for errors, implausible assumptions and underestimation of challenges and costs. Even the IPCC acknowledges that the ability to overcome economic, regulatory, social and operational challenges to high renewable energy market penetration “is not fully understood”.  Political backlash against renewable rollout is driven by valid concerns about cost, reliability, integration, land use and climate impact. The obstacles are not purely political, as Mann claims.  They are primarily technical, economic, scientific and social.

Mann’s attack on geoengineering dismisses and misrepresents the major risks of putting all eggs in the decarbonisation basket in a world that is already dangerously warmed. Preventing COCAWKI – collapse of civilisation as we know it – requires a careful, experimental programme to develop sunlight-reflection capabilities under robust international governance.  The Montreal Protocol is a useful model for an Albedo Accord.  Mann’s misinformed polemics sow confusion and delay effective climate action in a way that is not compatible with scientific method.

Regards

Robert Tulip

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[Bruce Melton -- Austin, Texas]

This link from our website has content on geoengineering that may be helpful:
The Long History of Geoengineering - https://healthyplanetaction.org/the-history-of-geoengineering/ 

Steep trails,

B

Bruce Melton PE
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President, Melton Engineering Services Austin
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[rob...@rtulip.net]

I have revised my comment about Michael Mann’s article to send as this proposed response to the Bulletin of the Atomic Scientists.

 

I would welcome discussion of this.

 

Response to Michael Mann on Geoengineering

Robert Tulip

In a recent Bulletin article, Professor Michael Mann dismisses solar geoengineering as a distraction from the supposedly “far safer and more reliable” climate strategy of clean energy transition, and makes incorrect claims about funding from Bill Gates. These points warrant response.

Gates funding

Mann writes that Gates “has financed for-profit schemes to implement geoengineering interventions that involve spraying massive amounts of sulfur dioxide into the stratosphere to block out sunlight and cool the planet.” In fact, Gates has given a few million dollars to academic research on solar geoengineering, with no public evidence that he has financed commercial deployment schemes of the type Mann describes. Harvard’s aborted SCoPEx project, funded in part by Gates, only planned to release a few kilograms of calcium carbonate in a small patch of the stratosphere to study particle behaviour; it did not involve sulfur dioxide and was nowhere near “massive” deployment. Fact-checking organisations such as Snopes, PolitiFact and Reuters have repeatedly rejected viral claims that Gates is trying to “block out the sun” or is bankrolling a sulfur-spraying program.

Sunlight reflection is essential planetary infrastructure

Mann’s pejorative argument is that “technofixes for the climate… displace far safer and more reliable options—namely the clean energy transition”. This ignores the emerging evidence that restoring lost albedo – the reflection of sunlight to space - is just as important as carbon action, arguably more so in the short term, given its greater capacity to prevent tipping points and easier technical feasibility.

An emerging view is that climate stabilisation will require well governed sunlight reflection as essential infrastructure, providing major benefits for weather management, biodiversity protection, sea level control and prevention of systemic disruptions. International governance should be a research priority, for example with an Albedo Accord inspired by the Montreal Protocol.

The missing albedo story

The core difficulty with Mann’s opposition to solar geoengineering is that recent science suggests a different approach. Mann’s own recent co-authored report A Planet on the Brink notes that recent warming “may be accelerating, likely driven by reduced aerosol cooling, strong cloud feedbacks, and a darkening planet.” That observation opens the need for a climate policy paradigm shift, integrating sunlight reflection and carbon action.  Planetary darkening deserves far more attention than it gets. It reveals the grave danger inherent in Mann’s opposition, namely that warming caused by a darker planet will swamp any feasible cooling from lower emissions.

Earth’s energy imbalance has more than doubled since the early 2000s. Data from NASA’s Clouds and Earth’s Radiant Energy System (CERES) satellite shows that reduced reflection of sunlight to space (albedo) is a primary cause.  Sunlight reflection measured by CERES has fallen by two percent since the early 2000s, from almost 100 watts per square metre to less than 98 w/m² measured in 2023-5 (see chart). This decline in planetary albedo is mainly due to the loss of clouds, aerosols, ice and snow cover. These are mostly feedback processes caused by anthropogenic warming, with some forcing from aerosol loss. NASA analysis indicates this darkening trend has heated the Earth through an increase in absorbed solar radiation since 2000 of about 1 w/m², and as Mann et al state, the trend appears to be accelerating.  Albedo-driven heating appears equal to or greater than the 0.8 w/m² radiative forcing from new greenhouse gas emissions over this period estimated by NOAA’s Annual Greenhouse Gas Index (AGGI).

Darkening of the planet is therefore contributing as much to current warming as the incremental greenhouse effect from new emissions, and possibly more. Albedo is not a side issue. The marked decrease in reflectivity is now central to climate dynamics. Slowing warming requires restored albedo.  Unfortunately, cutting emissions can do almost nothing to mitigate albedo loss in the short term.

Much climate policy discussion, including Mann’s article, is framed as if the only meaningful lever is emission reduction. That position brings the dangerous implication that tools to actively cool the Earth are illegitimate by definition. However, comparing CERES and AGGI data shows that albedo feedbacks are now at least as important to the recent observed warming acceleration as new forcing. Policy focus on emissions has neglected the impact of climate feedbacks. A rational strategy must target both.

Safe and Reliable?

With our world heading toward 2–3°C or more, and the COP30 communique rejecting mention of fossil fuels, climate policy should not pretend emission reduction alone is safer than sunlight reflection. A “risk–risk trade-off” should compare impacts of likely warming trajectories against the possible benefits and dangers of solar geoengineering. An increasing weight of opinion indicates that refusal to study the challenges of albedo management is neither safe nor reliable. 

Mann’s insistence that “the only safe and reliable way out of a climate hole is to stop digging” wrongly asserts that a crisis can only be mitigated by removing its causes.  In a medical comparison, our planet can be likened to a patient in the cardiac ward. Changing diet, like carbon management, is essential in the long run, but in the short run, treating a heart attack needs direct intervention. Similarly, the current radiative imbalance is mostly caused by emissions, but albedo feedbacks can only be mitigated by intervention to reflect more sunlight.

Mann argues that renewable energy and efficiency offer a “far safer and more reliable” path, citing studies that outline “very credible” routes to 100 percent non-carbon energy by 2050, and claiming that the barriers are political, not technological.  However, on top of their inability to slow the darkening of the Earth, these decarbonisation scenarios are contested for a range of reasons. Renewable energy roadmaps have been sharply criticised by energy-system modellers for optimistic assumptions about storage, transmission and demand flexibility, and for underestimating costs and integration challenges. The IPCC accepts that higher renewable energy penetration in the grid brings economic, regulatory and operational challenges that are “not fully understood”.

Political backlash against renewable energy targets is more than climate denial. The major economic transformation demanded for the net zero transition has raised legitimate concerns about cost, reliability, feasibility and land use – as well as its claimed climate impact. These questions reflect real technological and practical difficulties. Dismissing them as “purely political” is itself an ideological stance with dubious scientific basis.

Prudence requires a balanced precautionary approach.  With the world failing to decarbonise as fast as hoped, societies face greater risks if sunlight reflection technologies are not available.

Implications for the Bulletin

The Bulletin of the Atomic Scientists exists to host difficult conversations about existential risks from powerful technologies. On climate, that should include the need to restore planetary albedo in a rapidly warming world.  As Professor Mann himself acknowledges, recent acceleration in warming is likely caused by albedo loss as much as by new emissions. Warming feedbacks may be easier and more tractable to address than warming forcings. This means research into sunlight reflection is essential.  Policy trade-offs must be addressed clearly and openly to foster serious conversation about how best to respond to climate risk.

 

Hi all,

--

[H simmens]

Robert,

Your arguments as always are articulate, persuasive and backed up by the links you provide. 

My own approach on this subject whether to Michael Mann or anyone else is to avoid getting into a highly contested and unwinnable argument that net zero cannot or at least is highly unlikely to be reached by mid-century. There’s no way to win that argument as only time will tell. The risk of making that argument then is to distract from the central arguments against his position. 

Instead I employ the well established argumentative approach often used in law based on Concedendo/ Arguendo - the “ I concede for sake of argument” approach with respect to reaching net zero by mid century. 

The argument  - which is backed up by almost all of conventional climate science including the IPCC - is that reaching net zero will not lead to a reduction in temperatures or impacts for centuries. Quite the contrary as reducing emissions can only slow the increase in temperature not reduce it - a fact that is almost always obscured by proponents of ERA - emission reductions alone. 

No one will experience a more benign climate in 2060 or 2070 than they experienced a decade before when net zero was reached. 

And therefore any Climate policy that relies on ERA inherently cannot lead to the survival of civilization as we know it even if decarbonization is rapid and successful. 

To argue for ERA then is to argue that a world with the disappearance of coral reefs, accelerating sea level rise for centuries, more extreme and unprecedented weather and the almost certain activation of existentially devastating tipping elements such as the AMOC and the Amazon is an acceptable outcome for the billions of people much younger than Michael Mann and for many many future generations. 

I would therefore push back much harder on the moral hazard argument 

Here is a quote from Zeke Hausfather, hardly a strong proponent of cooling. This quote is in the context of arguments he also presents against SRM. 

 I believe his comment unmasks the morally indefensible opposition to fully and urgently investigating all possible cooling modalities. 

“I’m also cognizant that not treating the symptoms of climate change through something like SRM in the hopes that more suffering would speed up mitigation is arguably morally reprehensible in its own way. 

There is something profoundly wrong with the idea that we should let people die from heatwaves, floods, and famines in order to “motivate” stronger climate action.

SRM wouldn’t solve the underlying problem of emissions, but it could buy us time to get our act together without condemning billions to unnecessary suffering. “

I can’t think of a morally defensible effective argument that counters this statement. 

Herb

Herb Simmens
Author of A Climate Vocabulary of the Future

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

On Dec 4, 2025, at 6:02 AM, rob...@rtulip.net wrote:



I have revised my comment about Michael Mann’s article to send as this proposed response to the Bulletin of the Atomic Scientists.

 

I would welcome discussion of this.

 

Response to Michael Mann on Geoengineering

Robert Tulip

In a recent Bulletin article, Professor Michael Mann dismisses solar geoengineering as a distraction from the supposedly “far safer and more reliable” climate strategy of clean energy transition, and makes incorrect claims about funding from Bill Gates. These points warrant response.

Gates funding

Mann writes that Gates “has financed for-profit schemes to implement geoengineering interventions that involve spraying massive amounts of sulfur dioxide into the stratosphere to block out sunlight and cool the planet.” In fact, Gates has given a few million dollars to academic research on solar geoengineering, with no public evidence that he has financed commercial deployment schemes of the type Mann describes. Harvard’s aborted SCoPEx project, funded in part by Gates, only planned to release a few kilograms of calcium carbonate in a small patch of the stratosphere to study particle behaviour; it did not involve sulfur dioxide and was nowhere near “massive” deployment. Fact-checking organisations such as Snopes, PolitiFact and Reuters have repeatedly rejected viral claims that Gates is trying to “block out the sun” or is bankrolling a sulfur-spraying program.

Sunlight reflection is essential planetary infrastructure

Mann’s pejorative argument is that “technofixes for the climate… displace far safer and more reliable options—namely the clean energy transition”. This ignores the emerging evidence that restoring lost albedo – the reflection of sunlight to space - is just as important as carbon action, arguably more so in the short term, given its greater capacity to prevent tipping points and easier technical feasibility.

An emerging view is that climate stabilisation will require well governed sunlight reflection as essential infrastructure, providing major benefits for weather management, biodiversity protection, sea level control and prevention of systemic disruptions. International governance should be a research priority, for example with an Albedo Accord inspired by the Montreal Protocol.

The missing albedo story

The core difficulty with Mann’s opposition to solar geoengineering is that recent science suggests a different approach. Mann’s own recent co-authored report A Planet on the Brink notes that recent warming “may be accelerating, likely driven by reduced aerosol cooling, strong cloud feedbacks, and a darkening planet.” That observation opens the need for a climate policy paradigm shift, integrating sunlight reflection and carbon action.  Planetary darkening deserves far more attention than it gets. It reveals the grave danger inherent in Mann’s opposition, namely that warming caused by a darker planet will swamp any feasible cooling from lower emissions.

Earth’s energy imbalance has more than doubled since the early 2000s. Data from NASA’s Clouds and Earth’s Radiant Energy System (CERES) satellite shows that reduced reflection of sunlight to space (albedo) is a primary cause.  Sunlight reflection measured by CERES has fallen by two percent since the early 2000s, from almost 100 watts per square metre to less than 98 w/m² measured in 2023-5 (see chart). This decline in planetary albedo is mainly due to the loss of clouds, aerosols, ice and snow cover. These are mostly feedback processes caused by anthropogenic warming, with some forcing from aerosol loss. NASA analysis indicates this darkening trend has heated the Earth through an increase in absorbed solar radiation since 2000 of about 1 w/m², and as Mann et al state, the trend appears to be accelerating.  Albedo-driven heating appears equal to or greater than the 0.8 w/m² radiative forcing from new greenhouse gas emissions over this period estimated by NOAA’s Annual Greenhouse Gas Index (AGGI).

Darkening of the planet is therefore contributing as much to current warming as the incremental greenhouse effect from new emissions, and possibly more. Albedo is not a side issue. The marked decrease in reflectivity is now central to climate dynamics. Slowing warming requires restored albedo.  Unfortunately, cutting emissions can do almost nothing to mitigate albedo loss in the short term.

Much climate policy discussion, including Mann’s article, is framed as if the only meaningful lever is emission reduction. That position brings the dangerous implication that tools to actively cool the Earth are illegitimate by definition. However, comparing CERES and AGGI data shows that albedo feedbacks are now at least as important to the recent observed warming acceleration as new forcing. Policy focus on emissions has neglected the impact of climate feedbacks. A rational strategy must target both.

Safe and Reliable?

With our world heading toward 2–3°C or more, and the COP30 communique rejecting mention of fossil fuels, climate policy should not pretend emission reduction alone is safer than sunlight reflection. A “risk–risk trade-off” should compare impacts of likely warming trajectories against the possible benefits and dangers of solar geoengineering. An increasing weight of opinion indicates that refusal to study the challenges of albedo management is neither safe nor reliable. 

Mann’s insistence that “the only safe and reliable way out of a climate hole is to stop digging” wrongly asserts that a crisis can only be mitigated by removing its causes.  In a medical comparison, our planet can be likened to a patient in the cardiac ward. Changing diet, like carbon management, is essential in the long run, but in the short run, treating a heart attack needs direct intervention. Similarly, the current radiative imbalance is mostly caused by emissions, but albedo feedbacks can only be mitigated by intervention to reflect more sunlight.

Mann argues that renewable energy and efficiency offer a “far safer and more reliable” path, citing studies that outline “very credible” routes to 100 percent non-carbon energy by 2050, and claiming that the barriers are political, not technological.  However, on top of their inability to slow the darkening of the Earth, these decarbonisation scenarios are contested for a range of reasons. Renewable energy roadmaps have been sharply criticised by energy-system modellers for optimistic assumptions about storage, transmission and demand flexibility, and for underestimating costs and integration challenges. The IPCC accepts that higher renewable energy penetration in the grid brings economic, regulatory and operational challenges that are “not fully understood”.

Political backlash against renewable energy targets is more than climate denial. The major economic transformation demanded for the net zero transition has raised legitimate concerns about cost, reliability, feasibility and land use – as well as its claimed climate impact. These questions reflect real technological and practical difficulties. Dismissing them as “purely political” is itself an ideological stance with dubious scientific basis.

Prudence requires a balanced precautionary approach.  With the world failing to decarbonise as fast as hoped, societies face greater risks if sunlight reflection technologies are not available.

Implications for the Bulletin

The Bulletin of the Atomic Scientists exists to host difficult conversations about existential risks from powerful technologies. On climate, that should include the need to restore planetary albedo in a rapidly warming world.  As Professor Mann himself acknowledges, recent acceleration in warming is likely caused by albedo loss as much as by new emissions. Warming feedbacks may be easier and more tractable to address than warming forcings. This means research into sunlight reflection is essential.  Policy trade-offs must be addressed clearly and openly to foster serious conversation about how best to respond to climate risk.

 

To view this discussion visit https://groups.google.com/d/msgid/healthy-planet-action-coalition/01b901dc650d%247c34d650%24749e82f0%24%40rtulip.net.

[robert...@gmail.com]

Hi folks

For the past couple of weeks I've been preparing a response to an earlier thread that includes many of the issues raised here by RobertT's response to Mann and others' responses to that.

It's taken me quite a long time to do this in part because of having to deal with our domestic water supply being cut off for several days (not just ours but 24000 others' as well), and my EV developing some time consuming software faults that my local Mercedes dealership has so far been unable to resolve, even with help from Germany.  But RobertT's post below has kept the subject alive throughout these distractions.

I'll send it out in the next few minutes but in the original thread that provoked it.  The bottom line is that I have argued that RobertT's appeal to albedo is not correctly based on the science.  That doesn't mean we don't need SRM, quite the contrary, but it isn't justified by the reasons RobertT gives.  I think the scientific grounds for SRM are much more straightforward, and if properly presented, easy to grasp.

Regards

RobertC

On 04/12/2025 14:45, Robin Collins wrote:

A far more balanced BAS article and currently not Paywalled:

https://thebulletin.org/2024/06/the-university-of-chicago-new-climate-initiative/

On Thu, Dec 4, 2025 at 3:39 PM Alan Kerstein <alan.k...@gmail.com> wrote:

Herb,

I would suggest redirecting the debate from what should happen to what might actually happen. For example, my question for Michael Mann is what is his estimate of the likelihood that climate catastrophe will in fact be averted by adopting his approach - 90%? 10%? Either his answer won't pass the laugh test or it will expose the fatal flaw in his crusade against geoengineering.

Alan

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[Robert Chris]

Lots to comment on here.  This one's for Herb.

While I broadly agree with your remarks below, I have  a problem with your 'therefore'.  You say:

No one will experience a more benign climate in 2060 or 2070 than they experienced a decade before when net zero was reached. 

And therefore any Climate policy that relies on ERA inherently cannot lead to the survival of civilization as we know it even if decarbonization is rapid and successful. 

You start by making the point that net zero means stabilisation of warming at the level it has then reached.  Agreed.  But why 'therefore' must that mean COCAWKI?  It may do but if I'm on the fence and need to be convinced, I need those dots joining up.

There is also a fundamental problem about COCAWKI being a sufficient motivation to adopt policies to avoid it.  COCAWKI is an abstract fear that might strike at people in the future.  How far into the future?  Will I still be around then?  Might those who are still around then not be better placed to look after themselves?  Won't my government ensure that this doesn't happen to us?  What's the big problem about reducing the global population back closer to what it was in pre-industrial days?  Everyone's going to die sometime, isn't survival of the fittest (or luckiest) just how it's always been?  Against all those 'maybes', what exactly are you asking me to do (or not do) to make all this happen for the benefit of all these future people almost none of whom I know?  I could go on.

That's just seeing it at a personal level, but when you broaden the scope to a geopolitical level it becomes even murkier.  Might my country be a net beneficiary of COCAWKI because however bad it'll be for us, won't it be a hell of a lot worse for others?  With the large numbers of high-consuming people living in climatically threatened places, might their suffering and reduced numbers leave more resources available for us?  Similarly, won't their economic suffering reduce their military capabilities to our advantage?

The big question behind this is to what extent there is a universally accepted sense of moral propriety that includes an obligation to future generations.  I have referenced in the past Derek Parfit's Non Identity Problem in which he cogently argues that we have no such moral obligations.

Finally, I leave you with the question as to whether there needs to be some such moral obligation more or less universally accepted for there to be any real progress towards a globally effective climate regime.  If there does, who's working on putting that together, or does t already exist (and is just in hiding!)?  If there doesn't, why do we need the UNFCCC?

Regards

Robert

[Robert Chris]

This one's for Alan.

Isn't the problem with the 'laugh test' that those laughing at Mann's flawed argument are the ones with precious little power to influence the outcome.  The other's are tanning themselves on the sunshine emanating from his rear end.  What comfort might there be in too late discovering that that wasn't sunshine, it was bullshit!  Look on the bright side - either way, they'll end up the same colour.

Regards

Robert

[Alan Kerstein]

Herb,

I would suggest redirecting the debate from what should happen to what might actually happen. For example, my question for Michael Mann is what is his estimate of the likelihood that climate catastrophe will in fact be averted by adopting his approach - 90%? 10%? Either his answer won't pass the laugh test or it will expose the fatal flaw in his crusade against geoengineering.

Alan

On Thu, Dec 4, 2025 at 6:05 AM H simmens <hsim...@gmail.com> wrote:

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[Robin Collins]

A far more balanced BAS article and currently not Paywalled:

https://thebulletin.org/2024/06/the-university-of-chicago-new-climate-initiative/

On Thu, Dec 4, 2025 at 3:39 PM Alan Kerstein <alan.k...@gmail.com> wrote:

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[Robert Chris]

Hi Gene

I fear that you're making 2+2=5!

You say 'The effect of Earth’s albedo change was 0.64% of 341.6 = 2.19 W / m² warming, while global surface temperature rose 0.63°C, for an albedo decrease feedback rate of 3.5 Wm-2°C^-1.'  In effect, you're attributing all the warming in that period just to the albedo decrease.  What about the direct forcing from all the GHGs?  I don't think you can do the maths quite that simply.  The climate models do take account of the changing airborne fraction and the continuing direct forcing from CO₂ and the other GHGs that remain.  That's how I can say that when net emissions get to zero, surface temperature stabilises there.  What you're also not taking account is that past CO₂ emissions continue decaying after net zero, thus reducing their direct forcing.

I will acknowledge that the result will be slightly different for different values of ECS, but not so different that the basic principle is compromised.  Until you get to a phase change (aka tipping point), whenever you take away the positive forcing the feedback subsides.  Even after a tipping point, the same basic rules apply, it's just that the equilibrium position is shifted.

You're also not accounting for the feedback time lags.  These explain why the albedo decrease can be can be so much greater in Wm^-2 than the EEI.

If you want to construct some example scenarios you'd like to examine more closely, let me know in the next few days and I'll try and cover them when I do my HPAC presentation on 11 Dec.

Regards

Robert

On 06/12/2025 16:22, Gene Fry wrote:

Net zero means stopping acceleration of warming.

But Earth’s energy imbalance continues for many years to come.

The GHGs still trap heat (mostly in oceans), more than Earth radiates - 

until Earth reaches thermal equilibrium.

That equilibrium is primarily albedo feedbacks and carbon sinks turning to sources.

Warming feedback processes, mostly albedo feedbacks, continue.

The effect of these feedbacks is quite large.

And does not go away when human GHG emissions stop.

GHG emissions likely don’t stop when human GHG emissions stop,

depending on the evolution of carbon sinks turning to carbon sources.

(I know too little about sinks turning into sources, but it is a function of temperature, not GHG levels.)

Gene Fry

[Michael MacCracken]

Hi Robert--On the way to zero CO2 emissions, the emissions of short lived species will also presumably be going down, and since their lifetimes are so short, their concentrations will be dropping, thus reducing their contributions to radiative forcing. So, the forcing that persists over long times is mainly the CO2 perturbation and not the full, maximum GHG forcing. It is the short lifetime effect that helps offset the further warming that would go on due to the time lag created by the ocean if  instead the lifetimes of all GHGs were as long as CO2.

Mike

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[Robert Chris]

Hi Mike

Agreed.  So what?

Regards

Robert

[Robert Chris]

Hi Mike

Agreed.  So what?

Regards

Robert

On 07/12/2025 01:53, Michael MacCracken wrote:

[Michael MacCracken]

Basically, don't use CO2e. And was more an explanation for those raising questions.

Mike

[Michael MacCracken]

Other key human sources are sewage and garbage disposal, cattle and livestock. unsealed coal mines, and so on. Every bit counts.

Mike

On 12/7/25 7:06 AM, oswald.petersen via Healthy Planet Action Coalition (HPAC) wrote:

Hi Mike,

 

methane emissions are increasing mainly because of natural sources. These will not get less productive when CO2 emissions go down. That’s true only for the O&G industry, which produces around 10% of all methane emissions…

 

Regards

 

Oswald Petersen

Author of „GeoRestoration – Cool the Climate with Natural Energy“

https://amr.earth

https://georestoration.earth

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[Robert Chris]

Let's not get carried away by methane.  It is and always has been produced naturally.  There are only three meaningful policy approaches to methane.

First, adopt a low hanging fruit approach to reducing both anthropogenic and natural methane emissions.  There are too many to go after them all and in any event, the vast majority are too small to be economically or climatically worthwhile chasing.

Second, focus on reducing atmospheric methane using whatever economically acceptable means become available.

Third, focus on SRM cooling strategies because they will be the most effective way to reduce the risk of a methane permafrost burst that if sufficiently large could destabilise the global climate rapidly.  Ensure that any SRM driven reduction in the efficiency of atmospheric methane oxidation generates significantly less positive forcing than the negative forcing generated by the SRM.  

Regards

RobertC

On 07/12/2025 21:34, Tom Goreau wrote:

There are MANY sources of methane, each requiring separate control strategies.

 

For example I made the first methane measurements from Amazonian termites, hydroelectric reservoirs, cow manure in deforested pastures, Everglades swamps and grass fires.

 

That barely touches on the range of sources, while we await potential methane bombs triggered by anthropogenic warming……..

 

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[Jan Umsonst]

Hi all, hi Gene, 

that's our problem - if we stop our emissions warming rates will slow down but not stop.

There exist some issues here as temporal and spatial scales become highly important.

1: first we can't stop our emissions, just land use change and legacy emissions will remain substantial - ~1 Gt C y

2: New numbers from permafrost regions including abrupt thaw, fire emissions, and fire legacy emissions on top of "normal" thaw emissions are estimated to be some 300Gt in CO2e till 2100 in a medium warming scenario. So roughly another GT of C per year - first substantially lower then substantially higher.

2: the terrestrial carbon sink nearly collapsed in 2024. Likely, dry conditions, fires and microbial respiration the causes. So if we reach 2°C of warming we should not count on the terrestrial carbon sink at all.

3: ocean carbon sink could also be plateauing or even declining - not clear yet but substantial increases this century are now highly uncertain.

4: West Antarctica is now likely past it's tipping point which means a geologic methane feedback - the warnings are out. So we should expect another feedback here operating for centuries.

5: the trick to postulate that there is no warming in the pipeline had been to declare that decreasing GHG levels after zero emissions would negate the warming effect of continued ocean warming.

Unfortunately, the reality is that after an emission stop today, ocean warming would full scale continue the first year's to decline slowly afterwards as the effect of declining GHG levels would be first very small increasing with time needing at least decades to overcome continued ocean warming.

So we have at least 2 decades, likely more of warming in the pipeline.

6: this brings us to the next point - ocean heating continuing full on for another 5 years at least after emission stop would in itself be enough to trigger at least one more massive warming jump with smaller ones following for some time. That's in essence how ocean heat uptake regulated warming rates - some of the accumulating heat is "burped" out from time to time - just what El Ninos do...

7: for any GHG level to reach full effect takes some years, so also here some warming in the pipeline.

8: the current rates of GHG increase are at least 10 times faster than during past warming phases. This would mean even 1 Gt of annual CO2e emissions could be enough to cause further warming, especially as the terrestrial carbon sink could be near collapse. But we have likely higher annual emissions in the pipeline - feedbacks + legacy emissions.

All this would mean that even if we stop today our emissions to zero 2°C of warming we could have already in the pipeline as one more massive temp. Jump would happen with some warming afterward driven also by cloud feedbacks, further sea ice reduction, or snow cover declines.

If we want to come out of this we will need full scale massive GHG drawdown and solar dimming to buffer the worst of effects.

And currently it's by no means clear how effective SRM will be as the role of the heat already in the oceans is currently not accounted for in SRM experiments, besides of technically hurdles to distribute aerosols at the nano/microscale.

Important here: upper ocean stratification now reaching critical values is now starting to suppress the mixing of heat into deeper layers. And stratification won't go away so ocean heat uptake after reaching zero emissions in some decades would meet an ocean storing continued ocean heat uptake at shallower depths...

All the best

Jan

Gene Fry <gene...@rcn.com> schrieb am Sa., 6. Dez. 2025, 17:23:

Net zero means stopping acceleration of warming.

But Earth’s energy imbalance continues for many years to come.

The GHGs still trap heat (mostly in oceans), more than Earth radiates - 

until Earth reaches thermal equilibrium.

That equilibrium is primarily albedo feedbacks and carbon sinks turning to sources.

Warming feedback processes, mostly albedo feedbacks, continue.

The effect of these feedbacks is quite large.

And does not go away when human GHG emissions stop.

GHG emissions likely don’t stop when human GHG emissions stop,

depending on the evolution of carbon sinks turning to carbon sources.

(I know too little about sinks turning into sources, but it is a function of temperature, not GHG levels.)

Gene Fry

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On Dec 4, 2025, at 12:56 PM, Robert Chris <robert...@gmail.com> wrote:

You start by making the point that net zero means stabilisation of warming at the level it has then reached.  Agreed.  But why 'therefore' must that mean COCAWKI?  It may do but if I'm on the fence and need to be convinced, I need those dots joining up.

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[rob de laet]

Cooling can be done relatively fast through strengthening the green water cycle: Green Water Cools – Next Generation Climate Stabilizing Movement

Green Water Cools – Next Generation Climate Stabilizing Movement

Rob de Laet 

Project Lead Cooling the Climate

Member of the EcoRestoration Alliance

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Co-founder of Senang Eco Services

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.

[Bruce Melton -- Austin, Texas]

How do we know there is warming in the pipeline and that after net zero, warming does not stop?

Something that most of us know, that we do not describe fully, or maybe that we do not understand fully, is "how do we know there is warming in the pipeline when much of the discourse on this topic says there is none (or little) once net zero is achieved?" We all understand that natural feedback emissions only increase with stabilized warming because natural systems are already degrading and the degradation does not stop until the degrading forcing is removed and, that degradation feedbacks increase the degradation rate even with stable degradation forcing. This is standard systems science that applies to most if not almost all systems, but the modeling continues to say warming basically stops with net zero.

Hansen solves this problem by looking at proxies instead of modeling. With proxies, Earth's systems feedback processes (both slow and fast) are fully realized. Modeling only suggests fully realized feedback forcing and is reticent by design, because these quantities are not yet robust as their quantification is still being understood. Using fully realized feedbacks found in proxies, Hansen avoids this conundrum.

And on the realities of CDR, specifically industrial processes that are independent of natural systems degradation: This topic is extremely important as it matters not the state of the tech, costs, side effects, or the capacity of natural systems to sequester. It is mandatory regardless. Without it, geoengineering must continue and strengthen for generations if not hundreds of years, and as atmospheric GHGs increase (from warming in the pipeline), geoengineering typically becomes less effective. The geoengineering window is short. Ensuring effective and adequate implementation of industrial climate pollution removal and neutralization occupies a dual critical path with cooling interventions. Both are compulsory and complementary. Advocating for one and not the other creates a disconnection between the two task's shared critical path where climate change mitigation fails if both are not addressed simultaneously with identical motivation.

Steep trails,

MeltOn

Bruce Melton PE
Director, Climate Change Now Initiative, 501c3
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8103 Kirkham Drive
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On 12/5/2025 3:33 AM, oswald.petersen via Healthy Planet Action Coalition (HPAC) wrote:

Hello Herb,

 

the Roberts and you, and most on this forum, keep omitting the possibility to solve the problem with large, effective GHG removal. All the arguments flowing back and forth here omit this fact. We can and we will cool the climate with GHG removal.

 

Regards

 

Oswald Petersen

Author of „GeoRestoration – Cool the Climate with Natural Energy“

Atmospheric Methane Removal AG

Lärchenstr. 5

CH-8280 Kreuzlingen

Tel: +41-71-6887514

Mob: +49-177-2734245

https://amr.earth

https://georestoration.earth

https://cool-planet.earth

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[Michael MacCracken]

Dear Rob--

I'll agree that in arid regions, injecting water can reduce the peak temperature, the extra heat going into evaporation. However, in these regions, the addition of water vapor to the air raises the wet bulb temperature that in arid regions determines the minimum nighttime minimum temperature. 

A personal experience from my youth something like 65 years ago. Our family was on a summer tour of the country from the East to West coast and back. One night we ended up opening up our tent trailer in Paradise Valley, Nevada--which consisted at the time of a gas station and some USGS trailers for surveyors mapping out the region's desert hills. Daytime temperature was perhaps 100, but at night the canvas water bag that hung outside our car and was cooled by evaporation had icicles hanging from it--the nighttime temperatures in arid areas can get quite cold given the very low water vapor content.

So, the average daily temperature that is reported and recorded in the official records is the simple average of the daily maximum and minimum. What adding water vapor to the atmosphere does is reduce the daily maximum and increase the daily minimum, so the effect on the average change in temperature depends on which change is larger. In that the Clausius-Clapeyron is exponential with temperature, the amount of moisture associated with a temperature increases as the temperature goes up, so assuming the moisture stays around, which would seem to be the case if a forest is put in place as your approach is suggesting, would it not be the case that the change in temperature at the lower temperature (so the minimum at night) will be increased by more than the daytime maximum will be reduced? And if this is the case, then would not the average temperature, as it is calculated, become higher by raising the atmospheric moisture content. It might be the case that if the daily average temperature were to be calculated by averaging over each hour's temperature of the day that due to the longer sunlit period in the summer, the average temperature might drop,. But using the internationally agreed approach, have the calculations that you are reporting focused as much on the increase in the minimum temperature that will occur as on the reduction in the peak temperature? You might argue that it is the reduction in the peak temperature and not the increase in the minimum that matters most, although this might well be a bit contentious as low minimum temperatures do tend to better kill off disease vectors.

In any case, I'd like to know if your group is actually calculating the change in the average daily temperature, which is the international metric, or just focused on the reduction in the maximum temperature--and if this is the case, then it should be clearly and accurately stated.

Best, Mike MacCracken

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[Robert Chris]

Hi Rob

Numbers please.  Is it scalable to multiple GtCO2 and how is the CO2 permanently sequestered?  And how does this overcome the radiative inefficiency of CO2?

Regards

RobertC

[Bruce Melton -- Austin, Texas]

'Sup David,

To avoid the conflicts of perception on the feasibility of air capture tech, and on the social will, and or the ability of governments to pay to clean up climate pollution, what are we to do? Forget air capture and continue to geoengineer indefinitely, with increasing rates of intervention required as warming forcing increases, with increasing risks of side effects and failure as the rate of intervention increases, or, do we find a way to remove climate pollution from the sky? And, what about tipping points where natural greenhouse gas feedback emissions dwarf humankind's once Earth systems degradation becomes so severe that the degraded systems cannot self restore at some time about mid-century according to most tipping literature that identifies timelines for tipping responses to already activated tipping elements? 

My point is that if we do not assign an identical critical path weight to air capture as is required for cooling intervention, we all be dead puppies. Nothing about feasibility, costs, will or ability to pay matters. If we do not do both, we perish.

Besides, when will is concerned, or government's ability to pay, or robustness of proven technologies, air capture is currently smoking cooling interventions.

Steep trails,

B

Occidental Chemical 1PointFive Stratos unit in the Permian basin

History of Carbon Dioxide Removal
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Why our giga task of engineered cooling solutions will be nothing different than life on Earth every day.
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Bruce Melton PE, 2023
https://climatediscovery.org/Introduction_to_Advanced_Climate_Change_October_2023.ppt

 

Climate Emergency Response
The Urgent and Immediate Response Needed to Reverse Activated Climate Tipping With a Safe, Sustainable and Equitable Target of Less Than 1.0˚C Warming Above Normal
September 2021
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Bruce Melton PE
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On 12/8/2025 12:38 PM, David Price wrote:

Hi Bruce

I agree with much of what you said, but 

with regard to your last point about CDR, I have yet to read of any “proof” that large scale direct removal of CO2 from the atmosphere is technically feasible. (Capture of CO2 emissions at the stack as part of CCS is feasible of course, but that could continue only so long as humans continued to burn fossil carbon.)

In the long term (and in my not-so-humble-opinion this is really the only geoengineering solution that can work!) it will be necessary to deploy the “space parasol option” — a fleet of huge steerable reflective shields to intercept incoming solar radiation millions of km from earth.  

One of the attractions of this method is that it could be done incrementally, over decades to centuries, and paid for by multiple companies and/or governments working independently to pay off their carbon debts. 

David 

From my cellphone

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

On Dec 8, 2025, at 9:31 am, Bruce Melton -- Austin, Texas <bme...@earthlink.net> wrote:



<image001.png>

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[Gene Fry]

It seems to me that future methane emissions will be led very much by permafrost.

To the extent we can slow permafrost from thawing too much, that should keep methane sources in check.

Yes, we can eliminate most methane leaks from the oil & gas extraction & distribution processes.  We still have fugitive methane emissions from abandoned oil & gas wells and from abandoned coal mines.

We can make inroads on “human” emissions by eating far less beef (& feeding cows aspergensis) and growing rice without flooding.  We can equip more landfills with methane collectors.  But I don’t think all food waste emissions will go away, while termite emissions are likely to increase.

Based on Vostok ice core data, methane adds about 3°C to equilibrium warming from today’s CO2 levels.  That’s a heavy burden and will slow down motion toward equilibration, but a higher one than most people think.

Gene Fry

On Dec 8, 2025, at 3:08 AM, oswald....@hispeed.ch wrote:

Hi Robert,

 

methane accounts for 1/3 of global warming. There are good reasons for concentrating on methane first if you talk GHG removal. Regarding your three points:

 

1. You are right: Methane emission avoidance is first. However there is not much methane that can be avoided with adequate means. Most of them are in O&G, where the big polluters have been identified and are being addressed as we speak. One problem is that some of them are in places where climate awareness is, let’s say, deplorable. With methane emission avoidance it may be possible to reduce methane emission by around 1-5 %. That’s good, that’s important - but it is not enough.
2. Methane removal is the big game of the next 20-50 years. It is relatively cheap and quite easy to implement. Unlike SRM there is no strong opposition against it. It will happen and it will reduce methane to pre-industrial levels. This activity will stop Global Warming (GW) for at least 50 years. After that (hopefully) CO2 emission reductions will take over. 
3. SRM is not a methane related activity. However you are right, methane emissions are triggered by global warming, and henceforth the increasing methane emission from natural sources will stop increasing once GW stops. 

 

Pls note that methane also triggers tropospheric ozone, which will be reduced along with methane. This amplifies the impact of methane reductions. 

Pls note that TFCD (Tropospheric Ferric Chloride Dispersion) also contributes to albedo increase and CO2 removal. 

 

TFCD is a solution to GW, which is being disregarded. But that is about to change. 

 

Regards

 

Oswald Petersen

Author of „GeoRestoration – Cool the Climate with Natural Energy“

Atmospheric Methane Removal AG

Lärchenstr. 5

CH-8280 Kreuzlingen

Tel: +41-71-6887514

Mob: +49-177-2734245

https://amr.earth

https://georestoration.earth

https://cool-planet.earth

[Tim Foresman]

These diatribe exchanges are delightful to read.

In response to having corporations and governments pay off their carbon debts...let me be sceptible.

Ask the Japanese living in America after Pearl Harbor if they were ever compensated for their losses. Ask the Native Americans if they were compensated for the European real estate scam. Ask those of African descent if they were ever compensated (other than the free job training) for their inconveniences.

I believe the idea of corporations and governments paying off carbon debts to be too much of a stretch. 

Love this HPAC community. Stay cool. 

Peace, Tim

Dr. Tim Foresman

6219 Rockburn Hill Road

Elkridge, Maryland 21075

410-707-7352

www.earthparty.org

---

From: healthy-planet-...@googlegroups.com <healthy-planet-...@googlegroups.com> on behalf of David Price <da...@pricenet.ca>
Sent: Monday, December 8, 2025 1:38 PM
To: Bruce Melton Austin Texas <bme...@earthlink.net>
Cc: oswald....@hispeed.ch <oswald....@hispeed.ch>; H simmens <hsim...@gmail.com>; rob...@rtulip.net <rob...@rtulip.net>; John Nissen <johnnis...@gmail.com>; Planetary Restoration <planetary-...@googlegroups.com>; healthy-planet-action-coalition <healthy-planet-...@googlegroups.com>
Subject: Re: [HPAC] Proposed Response to Michael Mann for Bulletin of the Atomic Scientists

 

Hi Bruce

I agree with much of what you said, but 

with regard to your last point about CDR, I have yet to read of any “proof” that large scale direct removal of CO2 from the atmosphere is technically feasible. (Capture of CO2 emissions at the stack as part of CCS is feasible of course, but that could continue only so long as humans continued to burn fossil carbon.)

In the long term (and in my not-so-humble-opinion this is really the only geoengineering solution that can work!) it will be necessary to deploy the “space parasol option” — a fleet of huge steerable reflective shields to intercept incoming solar radiation millions of km from earth.  

One of the attractions of this method is that it could be done incrementally, over decades to centuries, and paid for by multiple companies and/or governments working independently to pay off their carbon debts. 

David 

From my cellphone

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

On Dec 8, 2025, at 9:31 am, Bruce Melton -- Austin, Texas <bme...@earthlink.net> wrote:



How do we know there is warming in the pipeline and that after net zero, warming does not stop?

<image001.png>

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[David Price]

Hi Bruce

I agree with much of what you said, but 

with regard to your last point about CDR, I have yet to read of any “proof” that large scale direct removal of CO2 from the atmosphere is technically feasible. (Capture of CO2 emissions at the stack as part of CCS is feasible of course, but that could continue only so long as humans continued to burn fossil carbon.)

In the long term (and in my not-so-humble-opinion this is really the only geoengineering solution that can work!) it will be necessary to deploy the “space parasol option” — a fleet of huge steerable reflective shields to intercept incoming solar radiation millions of km from earth.  

One of the attractions of this method is that it could be done incrementally, over decades to centuries, and paid for by multiple companies and/or governments working independently to pay off their carbon debts. 

David 

From my cellphone

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

On Dec 8, 2025, at 9:31 am, Bruce Melton -- Austin, Texas <bme...@earthlink.net> wrote:



How do we know there is warming in the pipeline and that after net zero, warming does not stop?

<image001.png>

To view this discussion visit https://groups.google.com/d/msgid/healthy-planet-action-coalition/432fc13a-cdca-4cce-82bb-39d13f776b76%40earthlink.net.

[rob de laet]

Hi Robert, 

here are three articles about the cooling through the green water cycle. Carbon has little to do with it, it's the water that cools. Obviously the tropical rainforests cool a hell of a lot more through the atmospheric hydrocycle than temperate forests do. 

https://discovery.ucl.ac.uk/id/eprint/10068488/1/Koch_1-s2.0-S0277379118307261-main.pdf 

https://agupubs.onlinelibrary.wiley.com/doi/10.1029/2023EF003663

https://medcraveonline.com/IJBSBE/IJBSBE-09-00237.pdf

Best, 

To view this discussion visit https://groups.google.com/d/msgid/healthy-planet-action-coalition/8160cdec-1e56-43b1-942e-d0e5c83d8797%40gmail.com.

[rob...@rtulip.net]

Hi Tim.  Corporations and governments respond primarily to interests, not morality.  A brighter Earth is a public good, like lighthouses.  This fact creates an incentive and interest for collaborative action to rebrighten the planet.  The carbon problem is likely to be solved when mining carbon from the air becomes profitable.  Your scepticism reminds me of Aristotle’s largely correct prediction that slavery would end when the looms could run themselves. 

 

The Bulletin of Atomic Scientists has declined to publish my submission. That means they are unwilling to correct the factual errors in Mann’s article.

 

Regards,

 

Robert Tulip