Cloud-brightening test part of geoengineering push amid climate change

A climate experiment involving spraying sea salt particles at the edge of San Francisco Bay to test the viability of future cloud-brightening was recently halted after a pushback by Alameda city officials. However, such research is getting funded and continued elsewhere as communities urgently seek solutions to climate change.
The average summer temperature in California is 3 degrees warmer than it was 125 years ago. More than half of that increase has occurred since the 1970s. The climate is changing, and the consensus is that it’s mainly due to the burning of fossil fuels. The impacts are visible: shrinking glaciers and ice sheets; rising sea levels, and more extreme weather.
But while the earth continues to warm, some climate scientists recently got the cold shoulder. Last month, the City of Alameda blocked scientists from continuing basic research into an experimental approach that may, one day, slow global warming. 
The research was being done by atmospheric scientists from the University of Washington, and a nonprofit called SilverLining. SilverLining is funded by a consortium of philanthropic foundations and individual donors. Despite the researchers’ credentials, the city council remained skeptical and voted unanimously to halt the work.
“We need to know more about this before you come to our city and start these experiments,” concluded Alameda Mayor Marilyn Ezzy Ashcraft.
The research involved a device that sprayed sea salt particles into the air from the deck of the USS Hornet, the decommissioned aircraft carrier and museum docked in Alameda. This aerosol may one day be used to brighten clouds, so they can reflect sunlight away from Earth and temporarily cool the planet. 
Scientists involved in the experiment are driven to gather more evidence since little is known about how the particles will behave.
“We want to provide the data to understand how this would affect the climate system,” testified University of Washington atmospheric scientist Dr. Sarah Doherty.
After the vote, the scientists left disappointed and declined CBS News Bay Area’s request for comment. City officials felt they did the right thing.
“This line of experimentation is very controversial because of the unintended consequences in other parts of the world,” noted Ashcraft.
However, the city of Alameda can’t stop the rest of the world. Some groups are going full steam ahead without the benefit of any good evidence and that presents a potential problem.
“No one has control over what people do in different parts of the world. There is no regulation in place. There’s no global treaty in place about this technology that regulates this technology,” remarked Lisa Dilling, an associate chief scientist with the Environmental Defense Fund.
At this point, she says, no one knows enough to safely deploy cloud brightening or any other form of solar radiation modification, also known as solar geoengineering.
“We absolutely think now is the time for doing research on the impacts of the technology,” said Dilling.
The nonprofit fund announced it will finance the research, issuing grants to teams around the world in order to better inform governments, scientists and the public. The first grants will be issued after Oct. 1. 
“We feel like we need to have strong scientific understanding before any decision is made about this,” Dilling said. “That could be a decision to not to use the technology in the future. It could be decision to use the technology in the future.”
Ezzy Ashcraft told CBS News Bay Area that she remains motivated to identify more immediate approaches and solutions.
“Alameda is doing a lot of things to address climate change and global warming,” she said. “Sea level rise is truly an existential threat to our island community.”

Carlos Castañeda

contributed to this report.