Mathijs H writes:*
On 4 October 1957, Sputnik 1 entered the Low Earth Orbit (LEO) to circle earth. Since then national space agencies have placed 6,000 satellites in the LEO, which has turned into a commons in which one agency's debris threatens other agencies' satellites. This space debris problem is well-known, and different mitigation, coordination and remediation initiatives are underway.
The urgency of the problem is obvious in Johnson et al.'s study, where the "best case scenario" (a 200-year halt to launches) leads to a stabilization of debris until 2055, but an increase afterwards. The cause -- cascading effects -- results when one collusion generates more objects, and in doing so increases the risk of new collisions. That exponential growth rate means that total debris will rise above the rate of decay (due to atmospheric drag).
It is clear that action is necessary, and the biggest space agencies seem to feel responsible in doing so. Examples of these actions are the Clean Space Initiative of ESA, NASA's orbital debris program, and the Inter-Agency Space Debris Coordination Committee (IADC). These actions, unfortunately, are not going to fix the problem. The first steps (mitigation and monitoring) need to be augmented with remediation, but it seems undecided who is going to do it. This existing coordination problem will not get easier when private companies increase space activities and the cost of this common pool resource problem.
Bottom Line: The space debris problem is urgent. Initiatives are taken, but not enough. Involvement of private companies will make action more complex to coordinate, and therefore the problem more difficult to solve.
* Please comment on these posts from my environmental economics students, to help them with unclear analysis, other perspectives, data sources, etc.