Of course, some of the most difficult to track debris was put up there in the name of science- the Telford needles, pieces of tether, and shreds of solar sails. If the big net experiment from a couple of weeks ago had gone awry, we'd have another difficult to track fabric-like bit of junk shredding itself into smaller yet still dangerous pieces up there.
https://en.wikipedia.org/wiki/List_of_space_debris_producing...
The linked bi-directional plasma solution seems really elegant to me. And is feasible even for objects several meters in size. With fewer possible mishaps than say laser ablation.
More detail here:
The quest To Conquer Earth's Space Junk Problem
Debris in high orbits isn't a big issue; there's too much space. Debris in low orbits falls out of the sky on a timescale of ~decades, thanks to aerobraking. So it should be constant, given a constant inflow of debris...
However, that is only true so long as collisions remain rare. Once there's too much debris, Kessler syndrome will cause it to 'breed' and close the orbitals for decades.
The above also doesn't account for super-popular high orbits, i.e. geosynchronous. A sufficient amount of debris in that orbit could close off that one for millennia (or until cleaned), but at least there are alternatives.
Also Geo orbit (while popular) is only useful if you get a fairly large degree of it all to yourself. My current understanding (correct me if I'm wrong) is that most satellites operate at fairly large distances from each other in Geo about 0.5 degrees apart is normal. Mostly because the antennas sending signals from have a wide beam at the point they hit the satellite and affect adjacent satellites. So they have to distance the Adjacent satellites far enough apart so as to be effective in communications. This isn't a problem for different frequencies, so you might stack a K and C band satellite on top of each other. But most of the Geo beasts have full capacity for the spectrum they are legally allowed to use.
Also, I'm speaking strictly about COMM satellites. I haven't done any practical application on anything else.
The final stage boosts the payload into its orbit then separates. Of necessity the final stage tends to be in a very similar orbit to the final payload, except weighing much more. For example, most sightings of the Sputnik spacecraft were actually sightings of the much brighter upper stage tagging along in orbit behind it. Ah but the stage is not necessarily done doing stuff yet, just not stuff it was intentionally designed to do. The stage will often have leftover propellant in it, and it was common to simply abandon the stage in place (on orbit) after its work was done. As a consequences, a lot of upper stages blew up on orbit after delivering payloads, creating yet another shower of debris into Earth orbit.
And finally you have the payload itself, which was very commonly simply abandoned in place once it became derelict.
Multiply all of that by the low operational lifespan of early satellites coupled with a high replacement cadence and you have a reason why Earth orbit got crudded up with debris in a short window of time.
Today we are considerably more sensible about the problems of space debris so our launches are much cleaner. Instead of every launch creating a new mess in orbit every launch generally just inserts 1 or 2 pieces of large, easily trackable components (the payload and the upper stage, if it wasn't deorbited). For LEO launches the upper stage is typically deorbited immediately, for GTO launches the upper stage typically takes a handful of years to orbitally decay and re-enter.
For this reason orbital debris has typically been on a flat or decreasing track over time during any given year. However, there are a few notable events in the past which have generated exceptional amounts of debris. One example is Project West Ford, which put thousands of tiny needles into orbit, which should have re-entered promptly except that some of the needles clumped up, leading them to have long-term stable orbits (which will last hundreds of years most likely), polluting some significant chunks of Earth orbit. Then you have the Iridium/Kosmos-2251 collision and the Chinese ASAT test, both of which injected huge quantities of debris into orbit.
In general, all of these things can be cleaned up given application of modest resources, and the fact that we are no longer polluting Earth orbit with debris as rapidly as we once were means that we should be able to sustain far higher levels of space activity with far lower risks due to orbital debris than today.
Or is it more of a thing that it only becomes more of a noticeable problem for us as humans when we are affected. Meaning that the only reason we have a problem with it now as opposed to some previous timespan is that we are sending more and more objects/satellites/etc into orbit and they are being damaged/destroyed/affected, so we therefore write about it and try and come up with ways to stop it?