THE MELTING OF THE WORLD'S ICE.

• Position: Effects of polar and mountain ice melting - Brief Article - Statistical Data Included

In the past century, much of the world's polar and mountain ice has melted, and in the past few decades the melting has accelerated. Ice is essential to global climatic and ecological stability, and as the ice turns to water, several major kinds of effects have been seen. First, as land-based ice on Greenland and Antarctic melts and drains into the oceans, sea-levels are rising--although the larger cause of sea-level rise is the expansion of water as it warms. Higher water combined with storm surges will likely inundate many coastal cities and ecosystems. Second, as glaciers and snow in the mountains melt and increase runoff, human settlements in major river valleys downstream from the mountains (such as the Gauges and Jiang [Pearl] river basins below the Himalayas) will become increasingly vulnerable to floods. Within decades, hundreds of millions of people could be displaced by floods or altered coastlines. As a result, coastal and riverine ecosystems all over the world are likely to be disrupted. Climate m odels also suggest that melting could cause major alterations in ocean currents, including a possible reversal of the warm Gulf Stream that now provides Europe with its mild climate. Ironically, some scientists believe a warming of the world's climate overall could bring a new ice age to Europe.

VULNERABLE RIVER BASINS Many of the world's cities are in watersheds down-stream from mountains where accelerated melting of glaciers or snow could contribute to severe flooding, especially if the basins have been heavily deforested. All of these basins have lost more than 50 percent of their original forest cover. Mountains Number of Large Cities Basin Upstream (over 100,000) in Basin Ganges Himalayas 85 Rhine Alps 68 Danube Alps 62 Yangtze Himalayas 56 Parana Andes 54 Indus Hindu Kush 34 Huang...