Graphic showing results of the tipping point and SAI simulations

[H simmens]

Here are the results in a remarkable graphic. 

Herb Simmens
Author of A Climate Vocabulary of the Future

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

On Dec 2, 2025, at 11:15 AM, H simmens <hsim...@gmail.com> wrote:



Link to the paper and the plain language summary below. 

Eager to hear what folks think about their approach and conclusions. 

Herb

Stratospheric Aerosol Injection (SAI) is a proposed method to cool the planet by releasing scattering particles into the upper atmosphere to reflect sunlight back to space. This climate intervention method would affect Earth's tipping elements, such as ice sheets and rainforests, which may exhibit abrupt or irreversible changes upon reaching critical thresholds. In this study, we use an Earth system model to analyze SAI's impact on climate metrics that are indicative of the risks of certain tipping elements crossing their thresholds. Our results show that compared to the scenario of increasing greenhouse gas emissions without artificial climate intervention, SAI could reduce the risk for many tipping elements. Deploying SAI at high latitudes is more effective at protecting northern cryosphere-related tipping elements such as Greenland ice sheet, Barents winter sea ice, and boreal permafrost. On the other hand, deploying SAI at low latitudes is more effective at protecting tipping elements such as Amazon rainforest and coral reefs. SAI targeting multiple temperature objectives including global mean temperature, equator-to-pole and interhemispheric temperature gradient, may not be the optimal approach for reducing some tipping element risks. Designing SAI strategies therefore requires carefully weighing the goal of stabilizing temperature pattern against minimizing tipping element risks.

Herb Simmens
Author of A Climate Vocabulary of the Future

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

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[Bruce Melton -- Austin, Texas]

Thanks Herb.

This seems like a great piece of work and needs further deep consideration. All works must be evaluated via their defining scenarios. The 1 C target here is far more meaningful than understated consensus scenarios. Their work on West Antarctica is extremely interesting because I believe the economic stresses of rising seas far outweigh other stressors in the critical path of warming effects. Their caveats here are quite meaningful with  prevailing Antarctic winds not meaningfully affected by their scenarios. Is this an artifact of their scenarios, or of not-included ocean feedbacks of ocean cooling with SRM versus atmospheric loading reduction... 

Steep trails,

MeltOn

Bruce Melton PE
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