By Ramin Skibba
In July 2012, a renegade American businessman, Russ George, took a ship off the coast of British Columbia and dumped 100 tons of iron sulfate dust into the Pacific Ocean. He had unilaterally, and some suggest illegally, decided to trigger an algae bloom to absorb some carbon dioxide from the atmosphere — an attempt at geoengineering, a tech-based approach to combating climate change. It was a one-off, the largest known geoengineering experiment at the time, and a harbinger for more to come.
Now a startup called Stardust seeks something more ambitious: developing proprietary geoengineering technology that would help block sun rays from reaching the planet. Stardust formed in 2023 and is based in Israel, but incorporated in the United States.
Its approach is novel: Most geoengineering research today is led by scientists in the U.S. at universities and federal agencies, and the work they are doing is more or less accessible to public scrutiny. Stardust is at the forefront of an alternative path: One in which private companies drive the development, and perhaps deployment, of technologies that experts say could have profound consequences for the planet.
…
For decades, researchers have explored a variety of approaches to hacking the climate. Today, the most common approach is a type of solar geoengineering that involves flying high-altitude aircraft or balloons to release reflective particles in the high atmosphere, well above the flight paths of commercial planes. The technique, known as stratospheric aerosol injection, requires deploying tiny, carefully- chosen particles in precise amounts. In order to work well, the particles need to be periodically replenished.
Scientists have accumulated evidence for this approach by studying natural events that have flung small particles into the atmosphere. For instance, after an eruption of Mount Pinatubo in 1991, sulfur dioxide and hydrogen sulfide hung in the atmosphere and measurably cooled the planet for more than a year.
“We know that sulfuric acid air pollution causes mortality, and we roughly know how much. There’s more than a century of studies. We’re very unlikely to be wrong about that,” said David Keith, head of the Climate Systems Engineering initiative at the University of Chicago and an advocate of geoengineering research. In a new study, Keith and his colleagues argue that the health risks of sulfate particulates in the atmosphere are heavily outweighed by the potential impacts of not deploying geoengineering technologies.
