Until there's no living thing in existence evolution hasn't failed. Humans are one of the most adaptable animals in known existence. We can find ways to survive in many different environments using technology. Our warm-bloodedness already allows us to survive in a wide range of environments naturally. And since we're the only animal that can leave Earth, we're the only species that can escape its fate, and persist.
I only see a few threats to humanity: nuclear conflict, asteroid impact, Yellowstone blowing. I think humans are in the final stages of nuclear conflict being a threat - the world is too interconnected for it to be viable. We really only have to worry about an asteroid impact and Yellowstone. Each of those things can be averted or stifled as our knowledge and technology grow. It's a race against the clock.
"On my business card I am a corporate president. In my mind I am a game developer. But in my heart I am a gamer." - Satoru Iwata
