Ice built up along the shore of Lake Michigan as temperatures in January 2019 dipped to around -20 degrees in Chicago, caused by the polar vortex dipping south.

The polar vortex is Earth's frozen guardian—but that guardian is starting to fail. This video dives into the science behind ...

A massive and surprising change is unfolding around Antarctica. Scientists have discovered that the Southern Ocean is getting saltier, and sea ice is melting at record speed, enough to match the size ...