Alameda nixes climate geoengineering experiment to test technology that could mitigate global warming (2024)

An experiment in Alameda involving spraying sea salt particles into the air to determine the feasibility of mitigating global warming, and subsequently halted over safety concerns, will not be resumed after a vote by the City Council.

Researchers from the University of Washington were performing the climate experiment on the flight deck of the USS Hornet Sea, Air & Space Museum in Alameda to determine if salt particles can increase the sun reflectivity of clouds, as part of its Marine Cloud Brightening Program.

Last month, the city halted the experiment following news reports of the misting process, including a New York Times articlethat Alameda Mayor Marilyn Ezzy Ashcraft said she had been surprised by. Alameda officials said the experiment was taking place without the city's knowledge and that it violated the city's lease with the Hornet.

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)."

In an hours-long meeting Tuesday evening that ended early Wednesday morning, the City Council heard from researchers and interested members of the public, with some calling in from around the world. While some commenters were upset and concerned about the experiments, others thought it was necessary to help tackle the impacts of climate change.

The debate centers on the controversy over geoengineering such as solar radiation management, carbon dioxide removal, or weather modification, and the possible unintended consequences of applying such technologies on a planetary scale.

Researchers with the Coastal Aerosol Research and Engagement (CAARE) Program said in a statement they were disappointed with the city council's vote not to resume the experiment, saying it was not designed to alter clouds or any aspect of the local weather or climate and were not cloud brightening activities. The research was an effort to study the transport and dispersal of sea-salt particles to test and improve models used to study the atmosphere and climate.

"The sea-salt studies involved spraying very small quantities of sea-salt mist. The City of Alameda engaged a team of experts to independently evaluate the health and environmental safety of the CAARE Program's sea-salt studies, which found that they are not expected to result in any adverse health or environmental effects," the statement said. "We provided extensive data to their process and all of the experts engaged affirmed the safety of the sea-salt spray involved in the studies. These supported our own evaluation that this is a safe, publicly accessible way to further research on aerosols in the atmosphere, to support environmental goals and to promote education and equity in science."

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."

However, the City Council's opposition to the experiment was not just against the science, according to council members, but rather against what they considered a lack of transparency on the part of researchers.

"We have been playing catch up [with researchers], and I did appreciate that eventually, the [non-profit climate research group] Silver Lining person reached out to me, but it was two months after the experiment began," said Ezzy Ashcraft. "And so we just had a lot of concerns from our residents about the health implications ... So we need to know more about this before you come to our city and start the experiments."

The mayor added that she hopes researchers use the City Council's decision "as a teachable moment and understand wherever you go next, you know, here's how you should do things and here's the way you sure shouldn't."

"We strongly welcome Alameda City Council's unanimous decision to say no to the first open-air Marine Cloud Brightening experiment in the U.S.," said Mary Church with the Center for International Environmental Law in a prepared statement. "Key concerns raised by council members focused on lack of sufficient information, notice and transparency. The rejection rightfully reflects the gravity of what's at stake for both local and global communities."

Researchers said that while they hoped the city would reconsider the decision to end the experiment, the team was already exploring alternative sites for their experiments.

More information on the Marine Cloud Brightening program can be found on the University of Washington's website.

In:
• Climate Change
• Alameda