Megaconstellation Pollution Could Quietly Cool Earth by 2029, Study Finds

A study in Earth's Future warns that pollution from deorbiting megaconstellation satellites and rocket launches could reduce sunlight enough to have a cooling effect comparable to solar geoengineering by 2029; satellites already account for about a quarter of space industry climate impact and are expected to rise to 42% by 2029, with annual rocket soot around 870 metric tons; while this cooling might seem beneficial amid warming, the effects are uncertain and the lack of regulation poses risks, prompting calls for caution and policy action.