Stardust Solutions, a privately funded Israeli‑American startup founded in 2023 by two former Israeli nuclear physicists, is promoting a solar geoengineering approach that it says could lower global temperatures at a cost of roughly $10 billion per million‑ton deployment. The company’s plan involves creating tiny particles from amorphous silica – a common food‑grade anti‑caking additive – and calcium carbonate, the primary component of eggshells, then spraying them into the stratosphere from high‑altitude aircraft or balloons.
How the technology is supposed to work
According to CEO Yanai Yedvab, each million tons of the silica‑calcium carbonate particles would reflect enough sunlight to produce about 0.9 °F (0.5 °C) of cooling. The particles would naturally settle out of the atmosphere after roughly a year, allowing governments to adjust the amount of cooling in a controlled, incremental fashion and avoid the so‑called “termination shock” that could occur if a program were abruptly halted.
Stardust emphasizes that its material is intended to be safer than the sulfur‑dioxide particles traditionally studied for solar geoengineering, which have been linked to acid rain and ozone depletion. The company points to the everyday uses of silica in foods, toothpaste and cosmetics as evidence of its safety, and notes that a 2016 Department of Homeland Security test released silica into the New York City subway without incident.
Scientific community raises concerns
Leading climate scientists, however, remain skeptical. Professor Raymond Pierrehumbert of the University of Oxford warned that “when the whole world is at stake, satisfying the needs of venture capitalists for profits should not enter at all into decisions about what, if anything, should be deployed.” He and others stress that the climate system’s response to large‑scale particle injection is still poorly understood.
University of Chicago professor David Keith, a prominent researcher on solar geoengineering, said Stardust is “greatly over‑claiming” that its particles pose lower risks than sulfur‑based alternatives. He highlighted the “hitchhiker hypothesis,” which suggests that airborne particles could adsorb harmful metals or other substances, potentially endangering human health when inhaled.
Sarah Doherty, an atmospheric sciences professor at the University of Washington, cautioned that “the current science does not support making financial bets on, or driving society toward, specific approaches.” She added that the technology could unintentionally alter rainfall patterns, shift monsoons and affect global food production.
Regulatory and funding landscape
Stardust has raised $75 million from venture investors and says it is working with policymakers to develop a regulatory framework for testing. Yedvab asserts that any outdoor trials would be conducted “under supervision and direct guidance of governments,” likening the process to clinical drug testing that begins with small, clearly defined experiments before scaling up.
Past attempts at real‑world testing have encountered strong opposition. A 2021 plan by Harvard researchers to conduct test flights in Arctic Sweden was abandoned after local resistance, and a 2022 experiment by U.S. startup Make Sunsets in Mexico prompted the Mexican government to ban further solar geoengineering trials.
What’s next for Stardust?
The company hopes to begin limited outdoor tests within the next few years, pending governmental approval. While the potential for a rapid, adjustable cooling tool is appealing to some policymakers facing increasingly severe climate impacts, the scientific community urges caution, extensive peer‑reviewed research and transparent, publicly funded studies before any large‑scale deployment.
As the debate continues, the $10 billion‑a‑year price tag underscores the massive financial stakes involved, prompting both investors and critics to watch closely how the technology evolves and whether it can be reconciled with the broader goal of reducing greenhouse‑gas emissions.
Original reporting: KEYT (Ventura/Santa Barbara) — read the source article.
