You'd be willing to destroy your career to publish a warning no one will need?
I think it's reasonable to assume that if it's not worth breaking the NDA, it's likely not an existential threat for the vast majority of humanity.
Now, does that mean that people who currently work upper-middle class knowledge work jobs aren't in for an exceedingly harsh economic reality check? Absolutely not.
But that's not really as serious as an existential threat to humanity.
On the one hand, you've potentially got an indeterminate number of future comfortable years based on a subjective assessment of how long you think it takes catastrophe to materialize, with the downside that you can't warn anyone and so no one will stop the coming catastrophe.
On the other hand you've got the immediate assurance of your current career being gone and high likelihood that you'll struggle financially as a result, with the upside that you can provide a warning to the public that they will almost certainly ignore and catastrophe comes anyway.
Given the risk/reward assessment of those two options, what do you pick?
Listen, I understand that, owing very likely to our differing backgrounds, you and I think differently.
Where threats are concerned, I'm a simple soldier and as such I see things simply.
I would raise the alarm without a second thought. I honestly don't know how anyone could reasonably believe they would have any other option?
Please understand, it's a job. I spot a threat to my unit, I report it up the chain of command.
It's not about whether or not there is a negative impact on me. It's not even about whether or not it serves a greater good; nor whether there is an ultimate benefit to my unit; nor whether I get brownie points when whatever you deem divine evaluates my soul in the hereafter.
It's my job to report. So I report.
I've never once considered the things you're talking about now when I was in any such situation. It was just a job.
Here's the thing, it kind of made me just automatically think a certain way. I know that if I see an existential threat, I'm reporting it. I believe anyone would. Not for benefit. Just because that's what you do. If you see a mass shooting in progress, you call the cops. I don't think there is a single person who thinks about negative impact or greater good. It's just automatic.
I was only saying that if the NDA would prevent them from reporting, then, to my mind, the threat is likely not existential. But, again, I do make room for the possibility that not everyone thinks like me. I just think it's very likely that people think exactly as I do when faced with that level of threat.
Maybe I'm wrong? That's fine.
The downside risk to yourself doesn't have to be existential for the upside to not be worth it.
Coming at this from a completely different angle, other people may see their duty to the law and the agreements they've signed as being more morally binding over their behaviors than their social obligation to raise the alarm. Not everyone uses the same formula to calculate which duty is most important.