Report published by Observatoire Défense et Climat and the Institute for International and Strategic Affairs, October 2026
Solar Radiation Modification (SRM) was once considered a largely theoretical and highly contested approach to addressing climate change, but is now increasingly attracting financial investment and driving technological development. Yet its geopolitical implications, remain insufficiently explored. A new report issued by the Observatoire Défense et Climat and The French Institute for International and Strategic Affairs (IRIS) addresses this gap, and provides an empirical investigation into the political economy of SRM and the geopolitical implications of its leading technological variant, Stratospheric Aerosol Injection (SAI).
The geopolitics of an emerging SRM sector and its implications for the EU
The authors identify three developments with important implications for the EU. First, the growing influence of private actors embeds SRM within broader techno-ideological agendas of technological acceleration, creating challenges for European sovereignty and strategic autonomy. Second, the concentration of SRM funding and research activity in a limited number of countries reinforces asymmetries in knowledge production. Third, the predominance of external funding in SRM research raises the risk of instrumentalising climate vulnerabilities in developing countries.
These trends are unfolding in a fragmented governance landscape characterised by competing visions, particularly between more precautionary and more permissive approaches. SRM governance is increasingly shaped through unilateral actions, civil society initiatives and voluntary standards, raising further questions about who sets the rules.
Strategic Aerosol Injection (SAI): an object of geostrategic competition?
SAI is currently the most researched and funded SRM approach, partly because it presents relatively low technical barriers. However, its development and potential deployment depend on capabilities that are unevenly distributed across states, raising important geopolitical questions.
The transboundary nature and uncertainty of SAI’s effects give the technology significant geopolitical implications.
Capability requirements and their geopolitical implications
The authors highlight three capability requirements related to SAI deployment that could have serious geopolitical implications:
- Dependence on the aerospace and propulsion industries: The needed aircraft and aerospace capabilities are often closely linked to defence industries and airspace authorisations, raising questions about which states could realistically pursue it and the scope for unilateral action.
- Dependence on supply chains for different types of aerosols: The type of aerosol raises distinct issues of resource geopolitics, such as supply chain vulnerabilities. Reliance on sulphates would tie SAI more closely to the fossil fuel industry, potentially reinforcing existing dependencies, while synthetic particles would require the development and coordination of industrial capacity across the entire supply chain on a massive scale.
- Dependence on detection and monitoring systems: Monitoring SAI deployment relies on satellite and atmospheric observation systems, but limited capabilities and concentrated control over data and infrastructure create dependencies and raise concerns about transparency, trust and states’ ability to independently assess potential SAI activities.
The appropriation of SAI as a political response and its potential for weaponisation
The authors argue that framing climate change as a security threat, could favour unilateral or small-group deployments driven by national interests, potentially fuelling geopolitical tensions, competing interventions and even diplomatic, coercive or military responses. SAI could thus offer a way of framing climate change in terms that align more closely with the exercise of sovereignty:
The interplay between these two trends – on the one hand, state-led approaches to climate security that tend to shift attention away from the causes of climate change and, on the other, the framing of SAI as a potential means of protection– could create favourable conditions for the appropriation of SAI as a political response, or even a security measure.
Moreover, the difficulty of distinguishing climate-related objectives from broader political and security motivations could lead SAI development or deployment to be perceived as hostile. Such ambiguity could be exploited by states, highlighting the potential for its weaponisation.
At the same time, SAI development is increasingly shaped by competition over technological capabilities rather than international cooperation.
Strengthening the EU's strategic autonomy
Building on these findings, the authors argue that the EU need to strengthen their independent research, detection and monitoring capabilities to better anticipate and assess SRM developments and their potential implications. This is essential not only to safeguard their decision-making autonomy and military preparedness, but also to strengthen their influence in emerging debates on SRM governance and position Europe as a credible actor in this field.
This summary is based on extracts from a report published by the Observatoire Défense et Climat and the Institute for International and Strategic Affairs, and written by Sofia Kabbej (Author; IRIS), Antoine Diacre (Data collection, infographics, and maps; IRIS, and Sami Nakib (Data collection, infographics, and maps). To read the full article, follow this link.
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