Get closer, though, and you’ll find not a simple cap of frozen water, but an extraordinarily complex interplay between the ocean, sea ice, and ice sheets and shelves. Unfortunately, these abrupt changes can self-perpetuate and become unstoppable as humans continue to warm the planet. A major driver of Antarctica’s cascading crises is the loss of floating sea ice, which forms during winter. But since then, the coverage of sea ice has fallen not just precipitously, but almost unbelievably, contracting by 75 miles closer to the coast. During winters, when sea ice reaches its maximum coverage, it has declined 4.4 times faster around Antarctica than it has in the Arctic in the last decade.