The Physical Evidence of Earth's Unstoppable 1,500-Year Climate Cycle

Policy Reports | Energy and Natural Resources | Global Warming

No. 279
Friday, September 30, 2005
by S. Fred Singer & Dennis T. Avery

Glacier Advances and Retreats

"Today, many glaciers are advancing, not retreating."

Historical records tell of glaciers retreating during the Medieval Warming, and advancing again like huge bulldozers during the Little Ice Age. Glacial moraines can be dated through carbon-14 from lichens and organic material in the debris where they mark their glaciers’ farthest advances. The moraines tell us the glaciers’ most recent advances occurred during the Little Ice Age — but the piles of rocky rubble often contain datable material from more than one advance.

Jean Grove, one of the top authorities on the Little Ice Age, recently did a review of the scientific literature, dating the age’s beginning “before the early 14th century” in regions surrounding the North Atlantic.”70 She says “field evidence clearly shows that glaciers on all continents expanded and fluctuated about forward positions during recent centuries.”

The UN Intergovernmental Panel on Climate Change, in its 2001 report, published data showing that one-half of the world’s glaciers had stopped shrinking, and that many of these had recently been growing.71

In the Arctic, the 18 glaciers with the longest observation histories were examined in 1997.72 More than 80 percent of them had lost mass since the end of the Little Ice Age. Surprisingly, however, there’s no evidence the Arctic glaciers have shrunk faster during the CO2-enriched 20th century. In fact, the researchers say the glaciers have been losing less mass per year as time goes by.73 The Arctic glaciers thus tell us their region is not currently warming. The glaciers retreated during the Medieval Warming for “at least a few centuries before 1200,” and then advanced three times during the Little Ice Age: the early 15th century, the middle 17th century and the last half of the 19th century.

On the Arctic island of Novaya Zemlya, the glaciers retreated rapidly before 1920 — but the retreat then slowed.74 After 1950, more than half of the glaciers stopped retreating, and many tidewater glaciers began to advance. The island’s temperatures in the last four decades have been lower than the previous 40 years — in both the winter and the summer.

In the Alps, Austria’s Gernot Patzelt says 55 glaciers have lost 50 percent of their area and 60 percent of their ice since 1850. He says they lost 20 percent of their area from 1855 to 1890, held constant from 1890 to 1925, lost another 26 percent from 1925 to 1965, held constant from 1965 to 1980, and have lost another 5 percent since 1980. The melting surges represent a lagged record of the surges in the Modern Warming.75

In Italy, the Ghiacciaio del Calderone, in the Italian Apennines, is the southernmost glacier in Europe. Historic records indicate that it has currently lost about half the mass it held in 1794, the earliest record of its surface area.76 Maurizio D’Orefice of the Italian Geological Service says the Calderone lost ice volume very slowly from 1794 to 1884 and then melted more rapidly until 1990.

"Most glaciers advanced during the Little Ice Age."

South American glaciers on the eastern side of the Andes — in Peru, Chile and Patagonia — all advanced during the Little Ice Age.77 (The eastern side is protected from the vagaries of the Pacific Decadal Oscillation.) The Peruvian glaciers were most extensive in the 17th century, those in Patagonia (farther from the equator) during the 19th century.

Tropical Glaciers also show the Little Ice Age and the Modern Warming. The University of Innsbruck’s Georg Kaser says the glaciers of South America, Africa and New Guinea all reached their greatest extents during the Little Ice Age.78 They’ve been receding “since the second half of the 19th century,” just as the end of the Little Ice Age would lead us to expect. The 1930s and 1940s brought a marked loss of the tropical glaciers’ ice masses. Around 1970 the melting generally slowed, and some glaciers even advanced. Then the 1990s again brought “marked glacier recession on all tropical mountains under observation.”

In New Zealand, the moraines of more than 130 glaciers show three particular periods of glacial advance during the Little Ice Age, with the farthest advances in 1620, 1780 and 1830.79 The Mueller Glacier on Mount Cook and the Tasman Glacier also reached their greatest extent during the Little Ice Age.80

In the South Shetland Islands, glaciers just north of Antarctica advanced during the Little Ice Age, based on the age of lichens81 and analysis of lake sediments.82

On the Antarctic’s Scott Coast, the Wilson Piedmont Glacier advanced at approximately the same time as the main phase of the Little Ice Age, based on carbon-14 dating of the organic material in the glacier’s raised beaches.83

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