Arctic sea ice plays an important role in Earth’s climate. Unlike glaciers and icebergs, which form from freshwater, sea ice forms when seawater freezes. Usually covered with snow, this ice cools the area around the north pole. The bright-white surface of sea ice reflects sunlight back into space like a giant mirror. During summer, when the ice melts, the ocean’s dark waters become exposed. The result: Less light gets reflected. Seawater heats up as it now absorbs this incoming energy, warming the near-surface temperature of the Arctic Ocean even more