‘Black ice’ is an ongoing phenomenon on the ice sheets in Greenland and Antarctica: in recent years, particularly in Greenland, the ice has been covered with a large amount of dark ‘dirt’ or ‘dust’. During the summer months, part of the western section of the ice sheet turns from brilliant white to inky gray as algae bloom across the surface. Some of it is also soot, which originated during forest fires in North America and was carried to Greenland by the winds. When part of the ice cap melts during the summer season, water flows through a drainage system, consisting of various channels and rivulets, to the sea. Soot and dark dust, on the other hand, remain behind on the ice, darkening the surface of the ice sheet more and more: as it becomes less reflective, it absorbs more heat than before and warms up, accelerating the melting of ice and snow. Read more on Livescience.com