Just want to point out that estimating low probability events such as the ones on this thread (solar flares, natural and man made disasters, virtual Armageddon, et cetra ) is almost impossible.

The "Black Swans" book has a good strategy for handling things that can't be pinned down as to likely hood.
NNT (the author) also admonishes against (SME's)experts who are more often wrong than right.
Look at finance for a lesson in wrong estimates.

Most of you do it instinctively here on ETS.
Don't worry about if it will happen, just plan to mitigate the outcome.

No one can really tell or calculate if (one of the previously mentioned events) is 5% or 75% likely.

We are better informed now in the day of internet communications, it has always been more likely than the public judged, we just didn't know.

Focus on being adaptable and prepared.
And no you are not paranoid, just informed.
Those feelings are a natural reaction to just how fragile civilization actually is.

Ultimately it is a question of WHEN not IF some of these things will happen.

Preparation, planning and skills are the only edge you have under you personal control.

Blue Sky's and good luck.