Scientists and aerospace engineers alike have long been worried about the consequences of junking Earth’s orbit. On this site the topic was first mentioned shortly after North Korea put an (apparently) useless satellite up there. This is a serious issue, as highlighted by this year’s conference on space debris, which was understandably worried about recent initiatives that consist of launching entire constellations of micro-satellites.
Should we expect the worst to happen? With SpaceX alone planning to plant about 3000 (yes, that’s three thousand) satellites in orbit during the next decade, I think it is a valid concern. Especially as this is done with little (if any) preparation to mitigate orbital pollution.