Recently, scientists conducted the first U.S. outdoor experiment to mitigate global warming by releasing microscopic salt particles into the sky from a decommissioned aircraft carrier in Alameda, San Francisco Bay. 

This experiment aimed to increase cloud cover to reflect more sunlight away from the Earth, a geoengineering method to slow global warming. The Coastal Atmospheric Aerosol Research and Engagement (CAARE) project, led by University of Washington researchers, was kept secret to prevent interference from critics.

The experiment, running through May, is now visible to the USS Hornet Sea, Air & Space Museum visitors. Concerns about transparency and potential unintended consequences remain, as similar projects have faced opposition. A Harvard experiment planned in Sweden was canceled due to Indigenous group protests, and Mexico banned solar engineering after Make Sunsets launched sulfate balloons.

As interest in geoengineering grows, there are calls for stronger regulations by the National Oceanic and Atmospheric Administration. Observers are closely watching the University of Washington project’s next phase, which involves another experiment on a pier about a mile offshore. Shuchi Talati of the Alliance for Just Deliberation on Solar Geoengineering emphasized the need for public engagement and inclusion of developing countries in decisions about solar modification technologies.