A good excuse to implement a UN World Tax huh?
Let's not, say we did, and keep our tax dollars.
Heck, let's see if Australia will let us set up a couple of asteroid observatories there, since the majority of uncharted ones are most likely in the Southern Hemisphere field of view.
Then, we can figure out a way to deal with any potentially real threats.
But in the mean time, we can still send up Affleck just to make sure...