Earth's population growth is slowing. As standard of living increases people have fewer kids. if the population stays relatively stable, we'll be fine. Climate change is an issue but it can be managed. Nuclear war can hopefully be diverted. There are several paths to the end of the world as we know it that are completely out of our hands. Super volcanoes, pandemics maybe, I'm sure there are others... Those happen rarely.

In our solar system we have pretty much unlimited growth, unlimited energy. If we go to space we can have a society that dwarfs any scifi society out there. We don't have to go. We'll be fine here on Earth for probably hundreds of thousands of years. But society can be much more if we choose to go to space.

Expanding to other stars is unnecessary and difficult if we never develop ftl travel. But even then, we still can go if we so choose. But not in our life time.