The experiment is being dubbed America's "first outdoor test to limit global warming."

"The Coastal Atmospheric Aerosol Research and Engagement, or CAARE, project is using specially built sprayers to shoot trillions of sea salt particles into the sky in an effort to increase the density — and reflective capacity — of marine clouds," reports Scientific American.

"The experiment is taking place, when conditions permit, atop the USS Hornet Sea, Air & Space Museum in Alameda, California, and will run through the end of May, according to a weather modification form the team filed with federal regulators."

The report notes that there is little data on the potential negative effects of such geoengineering projects and that they "could also harm communities and ecosystems in unexpected ways."

Shuchi Talati, the executive director of the Alliance for Just Deliberation on Solar Geoengineering, remarked how the test had been "kept under wraps" with little public engagement whatsoever.

A similar experiment that was set to be conducted over Sweden by Harvard University and had previously received funding from Bill Gates was cancelled last month after opposition from campaigners and Indigenous groups.

The Scientific American report warns that artificially creating cloud cover "could alter weather patterns in unclear ways and potentially limit the productivity of fisheries and farms."