Hacking the atmosphere: Geoengineering gets a reality check

- Solar geoengineering (also called solar radiation management, or SRM) is a controversial set of proposals to deliberately reflect a small fraction of sunlight back into space to cool the planet — essentially mimicking the effect of a large volcanic eruption. - The most-discussed method involves spraying aerosols (often sulfur dioxide) into the stratosphere, but other ideas include marine cloud brightening or thinning high-altitude cirrus clouds. - The article focuses on how geoengineering is moving from theoretical modeling to real-world experiments, and the growing push for governance frameworks — because any nation or even a wealthy individual could theoretically attempt it unilaterally. - Key players: Harvard's SCoPEx project (paused after Indigenous group objections), the US National Academy of Sciences, and various small-scale field trials by universities and startups. - The "reality check" refers to the gap between sci-fi hype and actual technical, political, and ethical hurdles: we lack the materials science, atmospheric monitoring, and international treaties needed to safely test or deploy these technologies.