Extinction
The Yellowstone supervolcano erupts and sets off a chain event in the Ring of Fire causing a worldwide catastrophe.
With the increasing instability of Earth's temperature due to Climate Change, the Yellowstone supervolcano erupts thousands of years before expected and the resulting action causes a near worldwide extinction. With the enormous eruption of the Yellowstone volcano, the Ring of Fire surrounding the Pacific ocean is activated and follows with several larger than normal eruptions. The magma and resulting fires kill almost a billion people while the fallout ash suffocates livestock, crops, animals, and people alike. The two billion or so people that survive soon die out from starvation along with several other species. Earthquakes destroy former cities all across Asia and North America, while the Amazon forest burns non stop for years. The Arctic ice melts and never returns causing the global sea levels to rise and flood major coastal cities.