Head in the sand? Or just screwed on?
"It is a certainty that this will happen, not a million to one long shot. It's probably already on its way. The only question is when will it happen."
True, so let's take our heads out of the sand and think for a moment.
For it to be worth while me getting off my arse and doing something today, it has to be (a) coming within the next couple of decades, (b) big enough to be a problem, and (c) small enough to be something I can deal with.
If we don't have (a) then it simply isn't economic to deal with now. Much smarter to spend the money on economic development and let the more advanced society of 2050 deal with it. (Imagine the folly of a 1950s world trying to deal with it. How much better placed we are now. How much better placed still will we be in 2050.)
If we don't have (b), who cares. Spend (some of) the money on cleaning up the mess.
If we don't have (c), who cares. Nothing can be done.
So, if someone would care to estimate the probability of an object meeting all those criteria, and would care to estimate the cost of dealing with it versus the benefit of spending the money on something else, we can make a rational, evidence-based decision. But, with respect to you all, I don't expect the readership of this esteemed rag to have *those* figures handy, so let's just enjoy the video instead.