The deorbits are controlled to occur over nonpopulated areas (i.e. the middle of the ocean). I don't think it amounts to much of a concern, compared to, say, the sum total emissions of all factories, power plants, ships, airplanes, and vehicles.
People used to think the oceans could just slurp up all of our garbage and plastic forever without a problem. Yet, here we are.
People used to think the oceans could just slurp up all of our garbage and plastic forever without a problem. Yet, here we are.