Antarctic glaciers retreating more quickly than expected?

As you read the amusing exercise in unbalanced reporting below, keep in mind Cryosphere's latest graph (below) of the Antarctic ice cover -- which shows that the overall Antarctic ice extent is very nearly 1 million square KM above the 20 year normal... Mustn't laugh! Only a Warmist would pretend not to know that as bits of the Antarctic ice break off, other bits grow. There's nothing static in nature

Retreat of glaciers in Antarctica due to climate change is happening more rapidly than expected, according a report by the USGS and the British Antarctic Survey release last Friday. The findings come on the heels of a study published last week in Geophysical Research Letters finding that Arctic sea ice could be completely gone in September by the late 2020’s — three times more quickly than previous estimates. (See this post in CEJournal for more information about that study.)

USGS geologist Jane Ferrigno and her colleagues are using satellite images, aerial photography and other data in an ongoing effort to map coastal areas of Antarctica. Their report, the first of several, examines Antarctica’s Larsen and Wordie Ice Shelves, and glaciers in the Antarctic Peninsula.

A total of 7,264 individual measurements on 174 changing ice coastlines using data from 1940 to 2005 reveals dramatic changes: 82 percent of the ice coastlines studied have been in retreat, ranging from hundreds of meters to kilometers in extent. Only 18 percent have been static or have advanced.

In addition, Ferrigno and her colleagues documented for the first time that the Wordie Ice Shelf has completely disappeared. They also report that the Jones Ice Shelf has vanished, and the Mueller Ice Shelf is in retreat.

The most dramatic changes, however, have been the calving of an iceberg measuring more than 6,000 square kilometers from the Larsen C Ice Shelf; the rapid retreat between 1986 and 2000 of the Larsen B Ice Shelf; and the quick breakup of the remaining northern part of Larsen “B” in 2002.

The researchers pin the blame on dramatically rising temperatures. They cite research showing that the Antarctic Peninsula has been warming at a rate of 3.7~1.6°C per century, which is “an order of magnitude larger than the global mean warming rate of 0.6~0.2°C.”

“This continued and often significant glacier retreat is a wakeup call that change is happening in our Earth system and we need to be prepared,” Ferrigno, lead author on the study, said in a statement released by the USGS. “Antarctica is of special interest because it holds an estimated 91 percent of the Earth’s glacier volume, and change anywhere in the ice sheet poses significant hazards to society.”

The retreat of ice shelves is a possible precursor to the deglaciation of the West Antarctic Ice Sheet, the researchers say. If that were to happen, sea level could rise 5 meters with catastrophic consequences for coastal areas around the world that are home to many tens of millions of people.

Ice shelves are believed to hold back glaciers, thereby slowing their march to the sea. So the worry is that with their disintegration, the West Antarctic Ice Sheet could begin to collapse. Indeed, the researchers on the report point out that after the collapse of adjacent ice shelves, many tributary glaciers began flowing to the sea faster, and the glacier surface began to drop, “confirming the buttressing role of the ice shelves.”

A paper published recently in Nature said the process could actually take a thousand or more years. So it will be interesting to see how the observations described in the USGS/BAS report square with the modeling in the Nature paper. (See this post in CEJournal for an analysis of news coverage of the Nature paper.)

The researchers conclude with one of the most astonishing warnings I have read in a paper of this kind: “The map portrays one of the most rapidly changing areas on Earth, and the changes in the map area are widely regarded as among the most profound, unambiguous examples of the effects of global warming on Earth"


Posted by John Ray. For a daily critique of Leftist activities, see DISSECTING LEFTISM. For a daily survey of Australian politics, see AUSTRALIAN POLITICS Also, don't forget your daily roundup of pro-environment but anti-Greenie news and commentary at GREENIE WATCH . Email me (John Ray) here

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