Oh what a jolly thread! But you missed out so many!
How about Betelgeuse goes supernova and bakes us with high energy x rays, killing all life on the planet.
Someone tests the worlds first antimatter explosion and it goes horribly wrong
The latest antibiotic-resistant super-bug comes about, which is worse than Ebola, and more contagious, and spreads across the world in days
There are plenty of other massively devastating eruptions you missed out on, such as the one in the canary islands which would trigger a wave so large as to kill most people a few hundred miles inland of the Atlantic basin
Or of course to go with the Mayan Eschatology, the world is unmade, and remade by the gods, and the next incarnation of man is created, or even Itzpapalotl sends the Tzitzimime down to earth to destroy it and remake Tamoanchan?
Who knows!