On the detectability by uninvolved parties of covert stratospheric aerosol injection programs producing transboundary impacts

[Geoengineering News]

https://iopscience.iop.org/article/10.1088/2752-5295/ae7148

Authors: Wake Smith, Matias Alberola, Jasper Boers, Karen Rosenlof and Daniele Visioni

21 May 2026

Abstract

Stratospheric aerosol injection programs are generally understood to be technologically straightforward and inexpensive relative to other climate interventions or remedies. This gives rise to the sensible question of whether uninvolved downstream states are at risk of having their climates covertly manipulated without their knowledge by other actors. This article seeks to put that fear to rest. We first survey the wide range of SAI experiments and deployments that are possible to clarify the deployed mass requirements necessary to create discernable transboundary impacts in uninvolved states. We then explore two methods that could be reliably used by civilian uninvolved parties to detect such deployments well before they reached the scale required to precipitate transboundary climatic impacts. Those involve detecting the plumes of sulfate precursors shortly after their injection by instruments already employed on satellites to monitor point source sulfur emissions and sighting the aircraft fleets that would be required to loft those precursors high in the atmosphere. While small process experiments with negligible surface impacts could easily be conducted covertly, we demonstrate that deployments of the scale required to create transboundary climatic impacts would be discernible by uninvolved parties long before any climatic impacts would occur.

Source: IOP Science