Maybe this is just a joke that sailed over my head, but this is obviously false and doesn't mean anything of the sort. Existential for whom? All you can definitely conclude is that the Earth won't explode if the climate increases by 15 degrees. You can guess that life would survive, but there were no humans back (or large mammals at all) back then. There's no reason to think we would make it.

> The people controlling the media won’t allow it. This is common knowledge.

This is just rank conspiracism. I know of no evidence to suggest that the media are somehow controlling events (?), laws (?), the "narrative" (?), simply to prevent nuclear reactors from being built. How? For what purpose?

And claiming "this is common knowledge"? Maybe that was just another joke, because normally when one says a conspiracy theory is true, one also claims that this is secret information that has to be carefully mined out of various data sources, because if everyone knows something is happening it's usually not a very good conspiracy.