Back in the day, 1969 in fact, I remember sitting up late one East Coast evening watching astronaut Neil Armstrong step onto the moon. As he set down a U.S. flag, I remember remarking to a friend: "Damn, the first thing we do when get there is litter!"
These days, humans have put up thousands of satellites orbiting the earth. These provide the backbone for our everyday communications, for our scientific understanding of the planet including tomorrow's weather, and even the GPS in our cellphones and my Garmin watch. Soon we'll need that mapping capacity to direct our self-driving cars. We count on all that stuff floating around up there without even thinking about it.
But apparently all that orbital clutter makes for an new threat, a consequence of our profligate habit of thinking that the universe is so big we can just leave stuff lying around. According to Charlie Stross,
There's an interesting discussion at the blog where I found this about how immanent and how destructive this might be. Evaluating it goes way beyond my expertise though I found the conversation interesting.
Humans evolved to make more and more and more -- because more was good for survival. Having managed to make so much more we're screwing up the planet, apparently we've also spread the malady into near-space.
Maybe it's just my apparently endless head cold doing my thinking, but looking at us through this lens, it's hard not to conclude there's simply too much of us.