It is also worth considering, that of the planned 12k satellites, only 4k will be in a higher orbit where long-living space junk can be created. The vast majori

It is also worth considering, that of the planned 12k satellites, only 4k will be in a higher orbit where long-living space junk can be created. The vast majority of the satellites will be in an orbit about 200 miles over ground where there is some minimal atmospheric drag, cleaning up any possible. Even without any other action taken, these satellites will reenter the atmosphere after 5-10 years on their own. Those satellites in the higher orbits require some care though. They wouldn't deorbit on their own and any space junk from collisions would stay around an extremely long time. For those sent up by SpaceX, there would be plenty of space, but if there are enough competing companies, things could get quite crowded. Of all people though, I would think that Elon is the most considerate about long-term environmental impact. After all, he doesn't want to block the path for his own Mars rockets.