Enlarge / "Wait, this global warming thing is gonna last how long?!?!" (credit: pxhxk) Mass extinctions aren’t fun times. There’s a reason (usually more than one, actually) species disappear in droves. That makes untangling these reasons a challenge. The geological crime scene investigation is tough given that clues can be elusive after millions of years, and the events are complex. The extinction that wiped out (most of) the dinosaurs, for example, saw both a massive asteroid impact and long-lived volcanic eruptions that covered most of what is now India in lava flows.