Are there any ongoing geoengineering experiments or projects?

1. The big picture: more funding, more field tests

Interest and public funding for geoengineering research rose sharply in 2024–2025, with the UK’s Advanced Research & Invention Agency announcing about £56.8m to study climate‑cooling technologies and explicitly funding small outdoor experiments and modelling work — a clear signal that field tests are moving from theory and lab models into real‑world trials ^{[1] [4]}.

2. Where actual outdoor work is happening or planned

ARIA’s programme lists a set of projects that include outdoor experiments — for example, drone or ship trials to test seawater sprays for marine cloud brightening, and small tests such as pumping water onto sea ice in Canada at up to 1 km² scale — and news reporting and NGO summaries describe five outdoor SRM experiments funded under that UK programme ^{[5] [6] [4]}.

3. Ocean experiments and chemistry interventions

Ocean‑based carbon removal and chemistry tweaks are already being attempted: Woods Hole’s alkalinity enhancement project was scaled back after criticism but received U.S. governmental approval to dump about 50 tons of lye (sodium hydroxide solution) into the Atlantic off Cape Cod in 2025, illustrating that real marine interventions are proceeding under regulatory oversight and controversy ^[3].

4. Academic programs and small‑scale SRM research

Major academic efforts are explicitly researching SRM: Harvard launched a Solar Geoengineering Research Program to generate science, policy and public‑engagement outputs and to reduce uncertainties around solar geoengineering ^[2]. Research networks and funders such as RFF, the Salata Institute and other institutions are funding social‑science and modelling work to inform governance and risk assessment ^{[7] [2]}.

5. Existing and past field experiments that inform current work

Field trials that probe aerosol–cloud interactions and cloud brightening have precedents: experiments like E‑PEACE ^[8] and more recent marine cloud brightening tests (including a Great Barrier Reef project) are cited as the technological foundation and justification for further open‑ocean trials ^{[9] [10]}.

6. Controversy and opposition: legal, ethical and ecological concerns

Multiple watchdogs, NGOs and some scientists argue these experiments are risky, could violate precautionary or biodiversity norms, and deserve moratoria or stricter oversight; the Center for International Environmental Law urged halting some UK‑funded outdoor experiments and cautioned they may contravene international law or the CBD moratorium ^[6]. Academic critics and policy voices also warn about unintended regional climate impacts and governance gaps ^{[11] [12]}.

7. Small commercial or private attempts — and regulatory responses

The U.S. EPA reports tracking potential commercial or private SRM activities: it challenged a start‑up called “Make Sunsets,” which reported releasing about 0.1 tons of SO2 to the stratosphere as of May 2025, illustrating that non‑academic actors are attempting small releases and that regulators are trying to identify and impose reporting requirements ^[13].

8. Who’s mapping and tracking the activity — and gaps in the record

Civil‑society mapping projects (Geoengineering Monitor, Geoengineering Map) and dedicated newsletters compile hundreds of projects — from carbon‑removal pilots to SRM tests — but they emphasize the record is partial and that no central global registry exists, meaning some experiments may escape easy public visibility ^{[14] [15]}.

9. What this means for policymakers and the public

The shift to real‑world experiments has intensified debates about governance, community consultation, environmental impact assessments and international norms; some funders explicitly require environmental reviews and local consultation before outdoor tests, while critics call for moratoria until stronger international rules exist ^{[4] [12] [6]}.

10. Limitations and what reporting does not show

Available sources document specific UK programmes, academic initiatives, NGO mappings and a few private attempts, but they do not provide a comprehensive, up‑to‑the‑minute global register of every small trial and private action; the exact number, locations and outcomes of all ongoing experiments are therefore not contained in the current reporting ^{[14] [15]}.

If you want, I can produce a concise list of named projects and funders from these sources (ARIA projects, Harvard SGRP, Woods Hole alkalinity trial, Great Barrier Reef MCB tests, Make Sunsets, and NGO maps) with direct links and exact dates cited.