[lxgr]

> please recall that the mass of de-orbiting man-made satellites came from the earth in the first place.

Then again, so are CFCs, CO2, radioactive materials...

Just because some elements naturally occur on Earth doesn't mean we're completely insensitive to where they end up. (That said, I have no idea if atmospheric Aluminium is actually a problem or not.)

[VBprogrammer]

I was watching a video the other day which happened to mention that sodium lasers are used to create artificial stars, used for calibration of adaptive optics in ground based telescopes. This works because one particular layer of the upper atmosphere is rich in sodium due to impact with sodium rich debris.

Obviously it requires a more scientific analysis but it does seem to me that burning a lot of shit on the atmosphere might be problematic.