A year on thin ice: Four seasons in a radically changed Arctic

2019-04-04 03:19:10

"THAW #10 by Timo Lieber"/www.timolieber.com By Fred Pearce CHANGE is afoot at the top of our world. Spring has sprung, marking a crucial moment in the Arctic’s annual cycle. Each year, the ice sheet reaches its maximum extent in March, then begins to shrink as temperature warm up. But this year, something is different. The floating sea ice, which at its peak normally extends as far as the eye can see and feels as solid underfoot as a continental shelf, is rotten. For the third year in a row, its maximum March extent is at a record low, following a winter of heatwaves. February temperatures were above freezing. These are the symptoms of a new Arctic that is being created – perhaps the most profound change to the look of our planet for millions of years, with consequences for the rest of the planet. In all likelihood the Arctic Ocean will soon be ice-free in the summer, surrounded by snow-free lands. “We are in a new Arctic regime,” says marine biologist Antje Boetius. Follow us as we take you through a year on thin ice. In the world’s most northern settlement, an international research town in Svalbard called Ny-Ålesund, the sun sets in the last week of October and doesn’t rise again until mid-February. The polar night ushers in freezing temperatures that are essential for the region’s annual cycle (see video and diagram). As the mercury plummets, ice starts to grow out over the ocean’s dark waters, covering it in a floating ice shelf. Winter has come. Historically,