I actually considered disease when creating this article, and it is one of the more problematic ones.

Even then though, a new plague is bound to devastate the dense human population eventually, but it won't kill us off.

Humans have several advantages that have kept us alive for so long. A huge one, and one considered to be why we outlived the neanderthals, is that we occupy pretty much every environment on earth. With a sort-of exception of Antarctica, humans occupy every continent.

While a plague could easily travel in our globalized world, it couldn't travel quickly enough to prevent countermeasures like countries closing their borders and developing vaccines. I played a disease simulator game online awhile back, can't remember the name, but I think it illustrates how difficult it would be to spread a deadly virus across the world. In the simulation, Madagascar almost always closes off their borders before the virus truly takes hold, which is pretty close to what you can expect in a real life situation. If one island nation survives then humanity survives.

Now, I have been using 10000 years as an example for my articles, and a lot can happen in 10000 years; almost all of these doomsday scenarios are likely to happen, but none of them could wipe out humanity on their own. The likelihood of them overlapping in such a way that all of humanity dies is exceedingly unlikely.

To our knowledge, we are the most intelligent and adaptive species that has ever lived. So early in our existence we have already begun space travel, which may save us until the eventual death of the universe as a whole. If we stay on Earth though we can likely expect to live millions of years like any other apex predator. Basically for as long as we can still breathe the air.