Why do we humans worry about the extinction of our species in a distant future?

Question

Why do we humans worry about the extinction of our species in a distant future?

Answer 1

Instead, many of us believe that we have the capability to extend human existence indefinitely as long as we continue to have the will and the desire to do so.

So, we have an obligation to future generations to do the best we can with the resources we now have available to us.

Answer 2

We are the only creatures that can.  So why not?  If dolphins were exposed to some secret science we don't know about, maybe we wouldn't be the only ones, but that's beside the point.

We think about it too much.  We are a fragile civilization.  We likely wouldn't survive before cockroaches could should some meteor or ice age event occur.  We worry because it's happened before.  We also worry with our religions as some religions predict such things like the end of the world.  Many different reasons, but that is why.

Answer 3

For the same irrational reasons that we worry about not waking up from a general anaesthetic