FOI release

FOI2025/00606: Atmospheric Aerosol Operations, Solar Radiation Management (SRM)

This request was refused in part, so we didn't provide some of the information the requester asked for. This may include information where we can neither confirm nor deny that we hold it.

Case reference FOI2025/00606

Received 30 June 2025

Published 29 September 2025

Request

Request Received: 30 June 2025

Thank you for your response and for providing previous FOI references FOI2025/00494, FOI2024/00862, and FOI2023/00301.

Having reviewed the contents of those published responses, I would like to refine my original request under FOI2025/00606 for further clarity and specificity. The previous disclosures relate primarily to modelling, laboratory studies, theoretical frameworks, and ethical governance surrounding geoengineering proposals.

This request now seeks information that extends beyond the scope of modelling and into the realm of applied engineering, field trial logistics, and deployment infrastructure, specifically regarding aerosol-based solar radiation management (SRM) or related geoengineering technologies.

Clarification Received: 7 July 2025

Please provide:

1. Any contracts, memoranda, proposals or internal communications relating to the practical delivery mechanisms or deployment systems (e.g. stratospheric aerosol injection, aircraft retrofits, drone platforms, balloon-based systems) funded, commissioned, or reviewed by UKRI between 2020 and 2025.

2. Names and affiliations of all private or public sector contractors, universities, or aerospace partners involved in the engineering, design, or feasibility testing of geoengineering dispersal hardware (e.g. nozzle design, delivery altitude platforms, chemical dispersal systems).

3. Any documentation or internal assessments of potential field trials, test runs, real-world dispersal scenarios, or logistical preparations — whether cancelled, postponed, or classified as “exploratory.”

4. Whether UKRI has coordinated with any military, aerospace, or climate-intervention partners (including but not limited to Met Office, MOD, CAA, Oxford University, Cambridge University, or private companies such as RollsRoyce, BAE Systems, Airbus, or NCAS) on technical or operational aspects of atmospheric manipulation.

5. Confirmation of whether UKRI has received, reviewed, or approved feasibility studies or white papers relating to real-world SRM or SAI applications, including projected costs, hardware prototypes, or environmental impact scenarios.

Response

Response Sent: 1 August 2025

Full details of the response are contained in the attached document.

Documents

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