Winter sea ice in the Arctic just hit a record low

The extent of sea ice blanketing the Arctic this winter fell to the lowest level on record, researchers announced this week, an ominous signal about the effects of climate change in the world’s fastest-warming region.

March is usually the peak season for Arctic sea ice; after months of ceaseless polar darkness, conditions are frigid and much of the ocean is frozen over. But just 5.53 million square miles of ice had formed as of March 22 this year — the smallest maximum extent in the 47-year satellite record, according to the National Snow and Ice Data Center. Since then, the ice has already begun to melt again.