Alameda climate experiment involving salt particles sprayed in air halted following news reports
Researchers conducting an experiment in Alameda to determine the feasibility of mitigating global warming by spraying sea salt particles into the air are looking at their next steps after the city halted the experiment for a safety review.
University of Washington researchers were performing the climate experiment on the flight deck of the USS Hornet Sea, Air & Space Museum in Alameda to investigate whether the salt particles can increase the sun reflectivity of clouds, as part of its Marine Cloud Brightening Program. Earlier this month, the City of Alameda said the experiment was taking place without the city's knowledge and it instructed researchers and the USS Hornet to stop the experiment because it violated the city's lease with the Hornet.
The city said in a public notice it was working with biological and hazardous materials consultants to evaluate the chemical compounds in the spray to determine if they are a hazard to humans, animals, or the environs around the Hornet. The notice also said there was no indication that the spray was a threat to human health or the environment.
On Monday, The University of Washington said in an emailed statement to KPIX that the experiments conducted by the Coastal Aerosol Research and Engagement (CAARE) Program at the USS Hornet "are not designed to alter clouds or any aspect of the local weather or climate." The university said the aerosol releases are part of a larger research program to study how clouds respond to particles in the atmosphere and the influence on climate, including from pollution aerosols, and the potential for brightening clouds to reduce climate warming.
The university added that the saltwater particle dispersal is well below established thresholds for environmental or human health impact for emissions. A March assessment of the experiment prepared for the university indicated such small-scale studies "fall below certain regulatory thresholds ... and produce an aerosol perturbation of a scale that will not measurably alter local or regional weather or climate.
While the university said the city of Alameda was informed of the plans for the experiment on the USS Hornet, news articles offering details of the particle dispersal prompted the city to request a more detailed review of the process. In a statement to KPIX, Antioch Mayor Marilyn Ezzy Ashcraft said the only advanced notice the city received from the USS Hornet was that a museum partner "will be doing climate change science (misting down the length of our Flight Deck to study "cloud" patterns)."
"Prior to the City's posting, our team had already agreed to pause our studies for a period while they undertook this review," the university said. "In fact, the CAARE facility is designed to help regulators, community members and others engage with the research closely, and we consider the current interactions with the city to be an integral part of that process. We are happy to support their review and it has been a highly constructive process so far.
Researchers said more information on the Marine Cloud Brightening program can be found on the university's website.
The City of Alameda said findings from its evaluation of the experiment will be provided to the public and shared with the City Council on June 4.