A Historic El Niño Is Coming That Could Cost the World Trillions

Every few years, weather nerds and agriculture analysts will talk about an upcoming El Niño, and then they mostly pass by with relatively few headlines. But sometimes El Niños end up being massively destabilizing -- leading to devastating droughts, flooding, and other catastrophes. And this year's emerging El Niño could end up being one of the big ones, with forecasters predicting record-breaking intensity. But what exactly is an El Niño, and what does it mean that this year's could be so big...