Microsoft’s billionaire founder Bill Gates is financially backing the development of sun-dimming technology that would potentially reflect sunlight out of Earth’s atmosphere, triggering a global cooling effect. The Stratospheric Controlled Perturbation Experiment (SCoPEx), launched by Harvard University scientists, aims to examine this solution by spraying non-toxic calcium carbonate (CaCO3) dust into the atmosphere — a sun-reflecting aerosol that may offset the effects of global warming.