 A warming of just basically one degree Fahrenheit of the Southern Ocean is allowing this warmer ocean water to get underneath these giant glaciers in West Antarctica and beginning to warm them from below. And so unlike Greenland, which is sort of melting like a popsicle on a hot summer sidewalk, Antarctica is sort of melting from below. And the reason that's urgent and alarming is because that puts a lot of stress fracture on these giant ice sheets.