Researchers quietly planned a test to dim sunlight. They wanted to ‘avoid scaring’ the public.
Hundreds of documents show how researchers failed to notify officials in California about a test of technology to block the sun’s rays — while they planned a much huger sequel.
The west coast of North America is one area the Marine Cloud Brightening Program has considered for a 3,900-square-mile solar geoengineering test. A boat is seen off the coast of Costa Rica. | Yuri Cortez/AFP via Getty Images
A team of researchers in California drew notoriety last year with an aborted experiment on a retired aircraft carrier that sought to test a machine for creating clouds.
But behind the scenes, they were planning a much larger and potentially riskier study of salt-water-spraying equipment that could eventually be used to dim the sun’s rays — a multimillion-dollar project aimed at producing clouds over a stretch of ocean larger than Puerto Rico.
The details outlined in funding requests, emails, texts and other records obtained by POLITICO’s E&E News raise new questions about a secretive billionaire-backed initiative that oversaw last year’s brief solar geoengineering experiment on the San Francisco Bay.
They also offer a rare glimpse into the vast scope of research aimed at finding ways to counter the Earth’s warming, work that has often occurred outside public view. Such research is drawing increased interest at a time when efforts to address the root cause of climate change — burning fossil fuels — are facing setbacks in the U.S. and Europe. But the notion of human tinkering with the weather and climate has drawn a political backlash and generated conspiracy theories, adding to the challenges of mounting even small-scale tests.
Last year’s experiment, led by the University of Washington and intended to run for months, lasted about 20 minutes before being shut down by Alameda city officials who objected that nobody had told them about it beforehand.
That initial test was only meant to be a prequel. Even before it began, the researchers were talking with donors and consultants about conducting a 3,900-square-mile cloud-creation test off the west coasts of North America, Chile or south-central Africa, according to more than 400 internal documents obtained by E&E News through an open records request to the University of Washington.
“At such scales, meaningful changes in clouds will be readily detectable from space,” said a 2023 research plan from the university’s Marine Cloud Brightening Program. The massive experiment would have been contingent upon the successful completion of the thwarted pilot test on the carrier deck in Alameda, according to the plan. The records offer no indication of whether the researchers or their billionaire backers have since abandoned the larger project.
Before the setback in Alameda, the team had received some federal funding and hoped to gain access to government ships and planes, the documents show.
The university and its partners — a solar geoengineering research advocacy group called SilverLining and the scientific nonprofit SRI International — didn’t respond to detailed questions about the status of the larger cloud experiment. But SilverLining’s executive director, Kelly Wanser, said in an email that the Marine Cloud Brightening Program aimed to “fill gaps in the information” needed to determine if the technologies are safe and effective.
“Alameda was a stepping stone to something much larger, and there wasn’t any engagement with local communities,” said Sikina Jinnah, an environmental studies professor at the University of California, Santa Cruz. “That’s a serious misstep.”
In response to questions, University of Washington officials downplayed the magnitude of the proposed experiment and its potential to change weather patterns. Instead, they focused on the program’s goal of showing that the instruments for making clouds could work in a real-world setting. They also pushed back on critics’ assertions that they were operating secretively, noting that team members had previously disclosed the potential for open-ocean testing in scientific papers.
Growing calls for regulation
Solar geoengineering encompasses a suite of hypothetical technologies and processes for reducing global warming by reflecting sunlight away from the Earth that are largely unregulated at the federal level. The two most researched approaches include releasing sulfate particles in the stratosphere or spraying saltwater aerosols over the ocean.
But critics of the technologies warn that they could also disrupt weather patterns — potentially affecting farm yields, wildlife and people. Even if they succeed in cooling the climate, temperatures could spike upward if the processes are abruptly shut down before countries have transitioned away from burning planet-warming fossil fuels, an outcome described by experts as “termination shock.”
Rep. Marjorie Taylor Greene (R-Ga.) has erroneously suggested that geoengineering is responsible for the deadly July 4 flood in Texas and introduced a bill to criminalize the technology. Retired Lt. Gen. Mike Flynn, a former national security adviser to President Donald Trump, has embraced similar untruths.
Meanwhile, more than 575 scientists have called for a ban on geoengineering development because it “cannot be governed globally in a fair, inclusive, and effective manner.” And in Florida, Republican Gov. Ron DeSantis signed a law last month that bans the injection or release of chemicals into the atmosphere “for the express purpose of affecting the temperature, weather, climate, or intensity of sunlight.”
Conspiracy theories involving the weather have reached enough of a pitch that EPA Administrator Lee Zeldin released a tranche of information this month debunking the decades-old claim that jet planes intentionally release dangerous chemicals in their exhaust to alter the weather or control people’s minds.
The Alameda officials’ sharp reaction echoed responses to past blunders by other geoengineering researchers. An experiment in Sweden’s Arctic region that sought to release reflective particles in the stratosphere was canceled in 2021 after Indigenous people and environmentalists accused Harvard University of sidelining them. The entire program, known as SCoPEx, was terminated last year.
“It’s absolutely imperative to engage with both local communities and broader publics around not just the work that is being proposed or is being planned, but also the broader implications of that work,” said Jinnah, the UC Santa Cruz professor, who served on the advisory board for SCoPEx.
“If we really were serious about the idea that to do any controversial topic needs some kind of large-scale consensus before we can research the topic, I think that means we don’t research topics,” David Keith, a geophysical sciences professor at the University of Chicago, said at a think tank discussion last month. Keith previously helped lead the canceled Harvard experiment.
Team sought U.S. ships, planes and funding
The trove of documents shows that officials with the Marine Cloud Brightening Program were in contact with officials from NOAA and the consulting firm Accenture as the researchers prepared for the much larger ocean test — even before the small field test had begun on the retired aircraft carrier USS Hornet. They had hoped to gain access to U.S. government ships, planes and research funding for the major experiment at sea. (NOAA did not respond to a request for comment.)
The program’s donors include cryptocurrency billionaire Chris Larsen, the philanthropist Rachel Pritzker and Chris Sacca, a venture capitalist who has appeared on Shark Tank and other TV shows. (Pritzker and Sacca didn’t respond to requests for comment.)
Larsen said research of marine cloud brightening is needed due to questions about the effectiveness and impacts of the technology. “At a time when scientists are facing political attacks and drastic funding cuts, we need to complement a rapid energy transition with more research into a broad range of potential climate solutions,” he wrote in an email to E&E News.
The 2023 research plan shows that the experiments in Alameda and at sea would have cost between $10 million and $20 million, with “large uncertainties” due to operational or government funding challenges and the potential to expand the “field studies to multiple geographic locations.”
They would require “significant cash at the outset” and continued support over several years, the plan said. It was submitted as part of a funding request to the Quadrature Climate Foundation, a charity associated with the London-based hedge fund Quadrature Capital.
The Quadrature foundation told E&E News it had given nearly $11.9 million to SilverLining and $5 million to the University of Washington for research on solar geoengineering, which is also known as solar radiation management, or SRM.
“Public and philanthropic institutions have a role in developing the knowledge needed to assess approaches like SRM,” Greg De Temmerman, the foundation’s chief science officer, said in a statement. The goal is to ensure that decisions about the potential use of the technologies “are made responsibly, transparently, and in the public interest.”
‘Avoid scaring them’
For more than a dozen years, the University of Washington has been studying marine cloud brightening to see if the potential cooling effects are worth the risks, the research team told Quadrature.
“The MCB Program was formed in 2012 and operated as a largely unfunded collaboration until 2019, when modest philanthropic funding supported the commencement of dedicated effort,” the plan said.
The source of the program’s initial financial support isn’t named in the document. But the timing coincides with the establishment of SilverLining, which is six years old.
SilverLining reported more than $3.6 million in revenues in 2023, the most recent year for which its tax filings are publicly available. The group does not disclose its full list of donors, although charities linked to former Democratic New York Gov. Eliot Spitzer and the late Gordon Moore, a co-founder of the chipmaker Intel, have reported six-figure contributions to the group. (The Bernard and Anne Spitzer Charitable Trust didn’t respond to a request for comment.)
“The Moore Foundation is not involved in the Marine Cloud Brightening Program,” said Holly Potter, a spokesperson for the charity, adding that “solar geoengineering research in not a focus of the foundation’s work.”
The program pitched Quadrature and other donors on the idea that its need for private philanthropy was only temporary. Public support would eventually arrive for solar geoengineering research, the team argued.
In a 2021 update for supporters, the team said it had received $1 million over two years from NOAA and the Department of Energy for modeling studies and had begun work on the modified snow-making machine that the researchers would later test in Alameda. That technology is also being used in a field trial along the Great Barrier Reef that’s funded in part by the Australian government.
At the same time, the donor report acknowledged the potential for “public perception challenges” like those that would later short-circuit the Alameda field test. “The MCB Program is well-positioned both in terms of its government ties, scientific analogues and careful positioning to move forward successfully, but this remains a risk.”
The plan for Alameda included elements to engage the public. The deck of the USS Hornet, which is now a naval museum, remained open to visitors.
But the team relied on museum staff to manage relations with Alameda leaders and carefully controlled the information it provided to the public, according to the documents provided by the University of Washington that included communications among the program leaders.
“We think it’s safest to get air quality review help and are pursuing that in advance of engaging, but I’d avoid scaring them overly,” said an Aug. 23, 2023, text message before a meeting with Hornet officials. “We want them to work largely on the assumption that things are a go.” No names were attached to the messages.
Then in November 2023, a climate solutions reporter from National Public Radio was planning to visit the headquarters of SRI for a story about the importance of aerosols research. A communications strategist who worked for SilverLining at the time emailed the team a clear directive: “There will be no mention of the study taking place in Alameda,” wrote Jesus Chavez, the founder of the public relations firm Singularity Media, in bold, underlined text. (Chavez didn’t respond to a request for comment.)
At the same time, the program was closely coordinating with government scientists, documents show.
The head of NOAA’s chemical sciences division was one of three “VIPs” who were scheduled to visit the headquarters of SRI for a demonstration of a cloud-making machine, according to a December 2023 email from Wanser of SilverLining. Other guests included a dean from the University of Washington and an official from the private investment office of billionaire philanthropist Bill Gates, a longtime supporter of geoengineering research. (Gates Ventures didn’t respond to a request for comment.)
The same month, the program detailed its progress toward the Alameda experiment in another donor report.
“The science plan for the study has been shared with our colleagues at NOAA and DOE,” said a draft of the report.
A Department of Energy spokesperson acknowledged funding University of Washington “research on how ambient aerosols affect clouds,” but said the agency hadn’t supported “deliberate field deployment of aerosols into the environment.”
Mayor wondered ‘where it’s leading to’
On April 1, 2024, the day before the Alameda experiment was launched, the program and its consultants appeared to be laying the groundwork for additional geoengineering tests, which an adviser said would likely need the support of federal officials.
Leaders from SilverLining, SRI and Accenture were invited to attend the discussion “to kick off the next phase of our work together” in the consulting firm’s 33rd floor offices in Salesforce Tower, the tallest building in San Francisco, a calendar invitation shows. Officials from the University of Washington and NOAA were also given the option to join. That evening, the calendar notifications show, everyone was invited to a happy hour and dinner.
Accenture, SRI, the University of Washington and NOAA didn’t directly respond to questions about the events. Wanser of SilverLining said in an email that the San Francisco meeting “was completely separate” from the cloud brightening program, even though it included many of the same researchers.
The following afternoon, team members and Accenture executives planned to give a sprayer demonstration to Pritzker, an heir to the Hyatt Hotels fortune and board chair of the think tanks Third Way and the Breakthrough Institute, and Michael Brune, a former executive director of the Sierra Club, according to another scheduling document.
It was an important moment for the team. The same technology that was being tested on the aircraft carrier’s deck would also be deployed in the much larger open-ocean experiment, the research plan shows.
“I was impressed with the team that was putting it together,” Brune said in an interview. He attended the demo as an adviser to Larson, the crypto entrepreneur who has donated to SilverLining via the Silicon Valley Community Foundation.
Brune, who lives in Alameda, said he wasn’t aware of the larger experiment until E&E News contacted him. “The engagement with leaders here in Alameda was subpar, and the controversy was pretty predictable,” he added.
In May 2024, city officials halted the experiment after complaining about the secrecy surrounding it. They also accused the organizers of violating the Hornet’s lease, which was only intended to allow museum-related activities. (The Hornet didn’t respond to a request for comment.)
At a City Council meeting the following month, Mayor Ashcraft said she wanted “a deeper understanding of the unintended consequences … not just of this small-scale experiment, but of the science, of this technology [and] where it’s leading to.” Then she and the other four council members voted unanimously to block the program from resuming its experiment.
Using federal aircraft ‘isn’t going to happen’
Between April 2024 and the City Council’s vote that June, the research team scrambled to limit public backlash against the test. By then, the controversy had attracted national and local media attention.
The information request from E&E News sought roughly 14 months of text messages from or to Doherty and Robert Wood, another University of Washington researcher, that included or mentioned their collaborators at SilverLining or SRI. Some of the text messages that were shared by the university did not specify the sender, and Doherty and Wood did not respond to questions about them.
The sender added, “for risk management and the project [it’s] an easy call, and we can cover it.”
But an unidentified second person responded that “the community could actually find it additionally problematic that the project kept the Hornet shut down.”
The team members sent each other letters from people who supported the program, including one from science fiction writer Kim Stanley Robinson, whose 2020 novel “Ministry of the Future” featured a rogue nation that unilaterally implemented planetary-scale solar geoengineering.
“The truth is that in the coming decades we are going to have to cope with climate change in many ways involving both technologies and social decisions,” he wrote to the City Council on May 29, 2024. The Alameda experiment “has the advantage of exploring a mitigation method that is potentially very significant, while also being localized, modular, and reversible. These are qualities that aren’t often attributed to geoengineering.”
After the council vote, SilverLining hired a new public relations firm, Berlin Rosen, to handle the media attention. It also discussed organizing local events to recruit potential allies, emails show.
Wanser, SilverLining’s executive director, wrote in a June 6, 2024, email to the research team that the program was considering “another run at a proposal to the city post-election, with, hopefully, a build up of local support and education in the interim.”
Meanwhile, even before Trump returned to office, the team had begun acknowledging that its mistakes in Alameda had decreased the likelihood of gaining government support for solar geoengineering research. Access to federal aircraft “isn’t going to happen any time soon,” Doherty, the program director, wrote to Wanser and other team members on June 14, 2024.
The studies that the program is pursuing are scientifically sound and would be unlikely to alter weather patterns — even for the Puerto Rico-sized test, said Daniele Visioni, a professor of atmospheric sciences at Cornell University. Nearly 30 percent of the planet is already covered by clouds, he noted.
That doesn’t mean the team was wise to closely guard its plans, said Visioni, who last year helped author ethical guidelines for solar geoengineering research.
“There’s a difference between what they should have been required to do and what it would have been smart for them to do, from a transparent perspective, to gain the public’s trust,” he said. source
A University of Washington experiment with “a machine to create clouds” was shut down by the city of Alameda — because the scientists didn’t bother to tell the locals what they were up to, Politico writes. They were 20 minutes into the test when city officials ended the experiment.
Donors to the Marine Cloud Brightening Program include “cryptocurrency billionaire Chris Larsen, the philanthropist Rachel Pritzker and Chris Sacca, a venture capitalist.” Can’t wait to find out what new conspiracy theories this spawns!
CA Test To Dim Sunlight Planned Quietly To Avoid Public Panic: Report
Researchers attempted to test a geoengineering technology that would’ve created clouds to block the sun’s rays.
Last year, a group of California researchers made headlines after they scrapped a secretive plan to test a cloud-making machine on a retired aircraft carrier on the San Francisco Bay. It was the nation’s first outdoor experiment to limit global warming by altering cloud behavior.
However, they were actually plotting something much bigger — a multi-million-dollar effort to spray saltwater into the sky and cool the planet by creating clouds over an area larger than Puerto Rico, Politico reported.
Politico uncovered details about the Marine Cloud Brightening Program in funding requests, emails, texts and other records. The details of the billionaire-backed solar geoengineering experiment were largely kept under wraps by researchers at the University of Washington.
The experiment was intended to run for months aboard the decommissioned USS Hornet in the Alameda area before city officials effectively shut it down, arguing that no one had told them about it beforehand.
The goal of the test was to limit global warming by spraying salt into the air to brighten clouds so that they reflect the sun’s rays away from Earth as they enter the atmosphere.
Internal documents show the researchers were already in talks with donors and consultants about a much larger 3,900-square-mile cloud-making experiment off the coasts of North America, Chile or southern Africa — well before the initial trial even began. The details come from more than 400 internal records obtained by E&E News through a public records request to the University of Washington.
Many of these plans were drawn up quietly, Politico reported.
The team behind the program relied on museum staff at the USS Hornet to manage relations with Alameda leaders and carefully controlled the information it provided to the public, according to the documents obtained by Politico.
“We think it’s safest to get air quality review help and are pursuing that in advance of engaging, but I’d avoid scaring them overly,” according to an Aug. 23, 2023, text message before a meeting with Hornet staff. “We want them to work largely on the assumption that things are a go.”
The strategy backfired.
When word got out about secretive experiment, locals were so rattled that the Alameda City Council voted to cancel it two months after it began.
Interest in this kind of climate intervention is growing — especially as efforts to cut fossil fuel emissions stall in the U.S. and Europe. But the idea of humans manipulating the weather has sparked political pushback and fueled conspiracy theories, making even small-scale experiments tough to pull off. source
Scientists Secretly Working on Plan to Test Blocking Sun From Huge Area of Earth
Scientists are racing to find potential ways to slow down global warming, going far as to investigate ways to dim the Sun.
The concept, known as solar geoengineering, has proven incredibly controversial in the past, with critics arguing that we simply don’t know enough about the risks, including the environmental and societal impacts of tinkering with the climate. Proponents don’t necessarily disagree, but they say the situation is already so bad that we need to consider drastic action, even if there is the potential for immense risk.
In that charged environment, the sometimes secretive ways scientists have been going about early geoengineering experiments are leaving the door wide open for mounting backlash and even conspiracy theories.
Last year, blindsided city officials in Alameda, California, ordered scientists from the University of Washington to halt an unannounced experiment using a device that would inject cloud-brightening particles into the atmosphere, citing fears of unintended consequences.
And now, according to extensive records obtained by Politico, it turns out the aborted experiment was meant to set the stage for a much larger-scale program that would have covered a 3,900-square-mile area — about the size of Puerto Rico — off the coast of North America, Chile, or south-central Africa.
“At such scales, meaningful changes in clouds will be readily detectable from space,” one 2023 report obtained by the publication reads.
But as experts told Politico, the University of Washington and its private partners, geoengineering firm SilverLining and nonprofit SRI International, didn’t exactly set themselves up for success.
“Alameda was a stepping stone to something much larger, and there wasn’t any engagement with local communities,” University of California, Santa Cruz, environmental studies professor Sikina Jinnah told the outlet. “That’s a serious misstep.”
However, university officials maintained that the program never aimed to “alter weather or climate,” and that there weren’t any “plans for conducting large-scale studies,” either.
Geoengineering has proven incredibly divisive, quickly turning into a hot-button political subject. Representative Marjorie Taylor Greene (R-GA), who has a long track record of furthering unsubstantiated conspiracy theories, mistakenly blamed the deadly flood in Texas in early July on geoengineering, without providing any evidence. Later this month, she introduced “weather modification” legislation based on the conspiracy theory.
Discussions have even filtered to the top, with EPA administrator Lee Zeldin entertaining legislation motivated by long-debunked conspiracy theories surrounding “chemtrails.”
Even huge swathes of the scientific community aren’t convinced that dimming the Sun is the answer, citing unknown knock-on risks that could make the cure worse than the disease.
They also often argue that geoengineering could serve as a band-aid fix, allowing world leaders to ignore the immediate causes of climate change, including the burning of fossil fuels and other sources of greenhouse gas emissions.
Those in support of efforts to dim the Sun argue we need to leave no stone unturned in our efforts to battle a growing climate crisis.
“At a time when scientists are facing political attacks and drastic funding cuts, we need to complement a rapid energy transition with more research into a broad range of potential climate solutions,” cryptocurrency billionaire Chris Larsen, who donated to the University of Washington’s program, told Politico.
Where all of this leaves the university and its private partner’s early experiments to seed clouds remains to be seen. Despite billions in funding from some notable donors, including the cofounder of Intel, the political opposition and public backlash could make it difficult for the project to get off the ground.
However, similar geoengineering projects outside of the United States could continue where the program left off. Earlier this year, the UK’s Advanced Research and Invention Agency announced it would invest $60 million in five small climate-cooling research projects, including “marine cloud brightening” to make them reflect more sunlight, refreezing the Arctic by pumping seawater from below the ice to the surface, and investigating the idea of injecting natural mineral dust into the stratosphere.
But getting the public on their side, particularly given how little even experts understand about the potential environmental impacts, could end up being a steep hill to climb. source