Is it all for not?

Last night on the TV I was watching the "doomsday channel" which was showing a number of doomsday scenarios that could occur. There were times I was laughing so hard that I missed some of the dialog, I mean this one scenario was we knew Earth was going to be blown up in 75 years and what we would do about it. The show went on on how we would build a spacecraft for maybe 250,000 people and propel it to some other galaxy with nuclear power. And then it showed rich people building their own space ship as they did not want to miss out.
Now first off, who the hell would do the work knowing the world was going to end and they themselves were not going to be saved? This thought would not leave my brain as the show went on and on up to the final moments of earth. But then I started to wonder.
Don't you ever get the feeling that if we were to fix the problems of the world, clean energy, food, wars and such some massive problem would show up and wreck it all? This is the"ultimate ironic moment" we are talking about here. I think many people get this feeling and that is why these problems are so hard to fix. If it wasn't for our sense of humour, I'm sure we would all go nuts don't you think?
7 billion lol.