Confirmed by science: our species is doomed.

[jeff47]

29. Humans will not go extinct.

Yes, sounds like a "rah-rah go people" statement, but it's really a measure of our adaptability and just how difficult extinction is.

Let's say climate change turns out to be 10 times worse than we currently fear. About 7 billion people die. Still not extinct - there's about 150 million people left.

Massive asteroid impact, like what killed the dinosaurs? Similar result - billions die. Still have plenty of people to carry on the species.

Viruses or other diseases? Nope. Again, can kill billions. But such an epidemic will cause society to break down, and we'll cluster into isolated groups. Some of those groups will survive.

Nuclear war? See: Asteroid Impact.

Eventually, our sun will become a red giant that will envelop the Earth. That's obviously bad for our species on Earth, but we already have the technology to build artificial habitats and attach them to spacecraft. We don't do it now because we don't have sufficient motivation to send people on a multi-generation one-way trip. The sun going red giant would provide that motivation. Plus we'll have a few million years of technology development to make it more practical.

There's really only three cases I can think of where extinction could be in the cards:

1) Annihilation by extra-terrestrials. If they can get to our planet, they probably have the technology to hunt down every last one of us, if they were so motivated.

2) All the stars go out. In a few hundred quadrillion years, every star will have burned out. That could be a problem. Depends on our ability to build artificial habitats at that time. If we don't have sufficient ability to generate power in the absence of any stars, we won't be able to keep ourselves alive.

3) Heat death of the universe. Eventually, protons decay. So in a few hundred sextillion years, the very matter that makes up the universe will have broken down. We obviously can't outlast that.