Practice 10　　Glaciers in Antarctica are melting faster and a

Practice 10　　Glaciers in Antarctica are melting faster and across a much wider area than previously thought, a development that threatens to raise sea levels worldwide and force millions of people to flee low-lying areas. Researchers once believed that the melting was limited to the Antarctic Peninsula, a narrow tongue of land pointing toward South America. But satellite data and automated weather stations now indicate it is more widespread. The melting also extends all the way down to what is called west Antarctica. By the end of the century, the accelerated melting could cause sea levels to climb by 3 to 5 feet-levels substantially higher than predicted by a major scientific group just two years ago. Making matters worse, the ice shelves that hold the glaciers back from the sea are also weakening.　　For years, the continent at the bottom of the world seemed to be the only place on the planet not experiencing climate change. Previous research indicated that temperatures across much of Antarctica were staying the same or slightly cooling. The big surprise was exactly how much glaciers are melting in western Antarctica, a vast land mass on the Pacific Ocean side of the continent that is next to the South Pole and includes the Antarctic Peninsula. The glaciers are slipping into the sea faster because the floating ice shelf that would normally stop them—usually 650 t0980 feet thick—is melting. And the glaciers' discharge is making a significant contribution to increasing sea levels.　　Together, all the glaciers in west Antarctica are losing a total of around 114 billion tons per year because the melting is much greater than the new snowfall. That's equivalent to the current mass loss from the whole of the Greenland ice sheet, New research found that melting glaciers will add at least 7 inches to the world's sea level—and that's if carbon dioxide pollution is quickly capped and then reduced.