“we estimate that a million satellites could mean that a teragram (one billion kgs) of alumina accumulates in the upper atmosphere – enough, alongside launch emissions, to significantly alter atmospheric chemistry and heating in dramatic ways we do not yet understand.

There is no public mandate for a single company in one country to make changes on that scale to the planet’s atmosphere.”
https://theconversation.com/a-new-space-race-could-turn-our-atmosphere-into-a-crematorium-for-satellites-276366