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. 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. Geoengineering projects, even those led by climate scientists at major universities, have previously drawn the ire of environmentalists and other groups. Such a deliberate transformation of the atmosphere has never been done, and many uncertainties remain. If a geoengineering project went awry, for example, it could contribute to air pollution and ozone loss, or have dramatic effects on weather patterns, such as disrupting monsoons in populous South and East Asia. Stardust ... has not publicly released details about its technology, its business model, or exactly who works at its company. But the company appears to be positioning itself to develop and sell a proprietary geoengineering technology to governments that are considering making modifications to the global climate"acting like a kind of defense contractor for climate alteration.