IF THE EARTH GETS WARMER, WILL THE ICE CAPS melt? That's a matter of hot debate among scientists who worry about possible climatic change. The Antarctic ice sheet alone is larger than the continental U.S. and holds a mass of water that if melted would raise world sea levels by about 60 m (200 ft.).
Coastal residents could take comfort in the prevailing view that Antarctica hasn't thawed for 14 million years, but that view is being challenged. A report in Nature suggests large portions of the ice cap may have melted just 3 million years ago.
The evidence centers on...