Algae fills a pool fed by Canada Glacier in the Dry Valleys region of Antarctica. With some experts forecasting the melting of half the Arctic’s summer sea ice by the century’s end, scientists are becoming increasingly concerned about the state of the Earth’s natural air conditioner.
If Greenland’s massive ice sheets were to melt, something that could occur over the very long term, they could raise the sea level by 23 feet (7 meters).