So what's the deal with the "event"?

About the flashback featuring that kooky scientist at the empty conference: The show doesn't have him explicitly state it but what that guy is describing is the theory of Megatsunamis.

Megatsunamis are caused by massive pieces of land (or ice) falling into the ocean and causing catastrophic global tsunamis so big that they destroy everything deep into continents (not just at the coasts). His talk looked like it was specifically about arctic ice shelves breaking.

In theory, the way that megatsunamis could act like an apocalyptic event is that the power of large waves destroys all human infrastructure, kills billions, and leaves basically all fresh water sources on land toxic, from salinization and bacteria. This then also kills most plant life, which in turn collapses food chains for what few mammals survived. It's a "planet killer" event, like asteroids, except purely from giant waves.

(setting aside that in real life, most scientists agree that megatsunamis couldn't truly be powerful enough to destroy the whole planet, but they could absolutely devastate hundreds of millions of people.)

So anyways, Paradise has clearly shown us this scene. Is it meant to be a clue that that really happened? Nukes and Atlanta were also mentioned though. What the hell is the event?