I think there is a very real possibility of large scale global disasters caused by volcanic activity. But sadly this guy lost all credibility as a pundit, when he included two wild, doubtful and unsupported assertions in his first few sentences. That, volcanic action caused the extinction of the Neanderthals, which not only is not proved, but goes against the current scientific consensus, that the causes of the extinction are probably complex, and certainly yet to be fully established. Then he said that volcanic activity caused the loss of "world wide crops", thirty nine thousand years ago. Sorry, but though I know that the origins of arable agriculture have been pushed back quite a lot recently, even maybe nearly to twelve thousand and the end of the ice age may be possible, though it is debatable, but world wide thirty nine thousand years ago !

So at that point I gave up.

I do like irony and find life ironic, so quite possible. Dropping a nuke on the San Andreas fault would probably do the trick too. Or some super volcano (Is there one at Yellowstone or something? perhaps I'm thinking some movie)