More evidence of Antarctic melting reported.

• Author: Mastny, Lisa
• Position: ENVIRONMENTAL INTELLIGENCE

Scientists have released the most compelling evidence yet that certain glaciers in Antarctica are melting rapidly. In April, researchers with the British Antarctic Survey (BAS) and the U.S. Geological Survey reported that 87 percent of 244 marine glaciers they surveyed on the Antarctic Peninsula have retreated markedly in the last 50 years.

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The three-year effort, reported in Science magazine, is the most comprehensive study to date of ice loss on the peninsula, a narrow chain of mountains stretching towards South America. To assess glacial trends, the researchers analyzed more than 2,000 aerial and satellite photographs dating back to the 1940s. The study suggests that marine glaciers are retreating by about 50 meters a year, although one (the Widdowson Glacier) has lost more than a kilometer of ice annually in the past five years. The loss is relatively new, scientists say, as most of the glaciers were growing as recently as 50 years ago.

The researchers also report accelerated loss of the large floating ice shelves along the peninsula's eastern side. Although this melting does not affect sea levels because the shelves already displace water, enhanced flow from glaciers further inland--many of which were held back...