Since the late 1970s, satellites have been spying on Antarctica’s sea ice, watching the whiteness expand and contract with the seasons. But they’ve never seen the ice quite like it is right now. Or rather, the lack of it—levels have fallen to record lows.
“Every single day so far in 2023, we’ve observed sea ice that’s been below average,” says climate scientist Zachary Labe of Princeton University and the National Oceanic and Atmospheric Administration, who created the graph below. The dark-blue line shows the median area of sea ice between 1981 and 2010, a figure called the “extent” that researchers measure in millions of square kilometers. The red line below all the others is the extent so far in 2023.