The Alameda, California, City Council voted Wednesday to deny scientists permission to continue a controversial test of technology that could one day be used to illuminate clouds.
The project, one of the first of its kind, involved spraying salt water on the deck of an old aircraft carrier moored at a city pier. The scientists behind it planned to test devices capable of creating and measuring aerosol clouds.
In the long term, the research could have served as a step toward a type of climate intervention known as marine cloud brightening. The concept, still largely theoretical, is to make clouds more reflective of sunlight, which would send more heat back into space and help mitigate global warming.
No such efforts are underway yet – instead, scientists are designing experiments to investigate how the technology might work. The Alameda trial would have been part of these efforts, but the City Council unanimously voted against it.
The episode placed Alameda officials at the center of a public debate that extends far beyond the city, about the promises and dangers of geoengineering and whether tests of this type of technology should be carried out. The council’s decision follows similar actions in other areas, including a State ban on geoengineering implemented in Tennessee and the abandonment of a geoengineering project that Harvard scientists sought to implement In Sweden.
However, the council’s vote was not a repudiation of science or the idea of geoengineering, but rather of the researchers’ approach. Members complained that project leaders were not transparent, did not provide sufficient feedback from medical professionals about their safety, and took the wrong step by starting spraying salt water first and then asking for permission.
The University of Washington scientists responsible for the trial had actually already begun their work — and had not widely publicized the details in advance — when Alameda city leaders learned more about the matter from reporting in The New York Times. and other media. Researchers sprayed salt water along the deck of the USS Hornet, which is now used as a museum on the Alameda waterfront. Their plan called for spraying three times a day, four days a week, for 20 weeks.
But after city leaders became aware of the project, they quickly shut it down to investigate its safety and hold a vote on its fate.
The idea of cloud glow is to increase the number of water droplets inside the clouds to increase how reflective they are. Sending more sunlight back into space in this way could reduce Earth’s overall warming, but it wouldn’t help solve other climate problems, like ocean acidification.
Geoengineering research continues to be a difficult sell to the public despite the worsening effects of climate change, and the events at Alameda demonstrate the harsh skepticism scientists face about even the most basic experiments.
Much of City Council members’ deliberation avoided the project’s broader implications, focusing instead on potential local health risks — including the spray’s proximity to school and neighborhood soccer fields — and whether city leaders project had taken appropriate regulatory measures.
Sarah Doherty, a professor at the University of Washington who manages the cloud brightness research program, faced sharp questions.
“In fact, I want you to tell us exactly what you did to us,” said Councilwoman Trish Herrera Spencer. “I think it’s unfortunate. I think you all should be able to tell us what you sprayed when you sprayed so we all know what we were exposed to.”
Doherty told the council the sprays contained extremely low concentrations of salt and would have little impact on the environment.
“We are not lighting any clouds. Let’s not change the climate. We’re not changing the climate,” Doherty said.
A consultant hired by the city also told the council that the project was safe and “not expected to present an unacceptable risk to the surrounding community.”
Other council members regretted having learned about the project through the news reports.
“I don’t like hearing things or getting news from The New York Times. I would actually prefer to have the opportunity to review them,” said Councilor Malia Vella.
Project organizers, including Doherty, said in a statement they were disappointed with the city’s decision and began exploring “alternative locations.” The group added that it sought to be “completely open and transparent”.
“All experts involved affirmed the safety of the sea salt spray involved in the studies,” the scientists wrote. “This supported our own assessment that this is a safe and publicly accessible way to continue research on aerosols in the atmosphere, to support environmental goals, and to promote education and equity in science.”
Alameda Mayor Marilyn Ezzy Ashcraft said the city did not need to be at the forefront of this type of research.
“There are so many conflicting considerations that we need to take into account and I don’t think you’ve made your case,” Ashcraft told Doherty at the board meeting.
Meanwhile, some external environmental organizations have expressed opposition to the project based on more global concerns.
More than 70 environmental groups released a statement last month urging Alameda to cancel the project. Opponents were worried that someday widespread use of geoengineering technology could alter the climate with unintended consequences or reduce the ambition of global efforts to stop using fossil fuels.
“Our real concern with this is that it opens Pandora’s box,” said Mary Church, geoengineering campaign manager at the Center for International Environmental Law.
Church, speaking before the vote, said his organization was not concerned about the immediate impacts on Alameda, but rather that the project would lay the groundwork for widespread weather manipulation.
“It does nothing to address the root causes of the crisis,” she said.
This article was originally published in NBCNews. with
