family:Arial;”>Is a New Ice Age Under Way?
by Laurence Hecht
“Watch out, Al Gore. The glaciers will get you!” With that appended note, my friend, retired field geologist Jack Sauers, forwarded to me a report that should have been a lead item in every newspaper in the world. It was the news that the best-measured glacier in North America, the Nisqually on Mount Rainier, has been growing since 1931.
The significance of the fact, immediately grasped by any competent climatologist, is that glacial advance is an early warning sign of Northern Hemisphere chilling of the sort that can bring on an Ice Age. The last Little Ice Age continued from about 1400 to 1850. It was followed by a period of slight warming. There are a growing number of signs that we may be descending into another Little Ice Age—all the mountains of “global warming” propaganda aside.
Our current understanding of the long-term climate cycles shows that for the past 800,000 years, periods of approximately 100,000 years’ duration, called Ice Ages, have been interrupted by periods of approximately 10,000 years, known as Interglacials. (We are now about 10,500 years into the present Interglacial.)
What Causes Ice Ages
These cycles are not mere statistical correlations, as some Wall Street prognosticator working at the modern PC version of a ouija board might spin out. They are determined, with great scientific precision, to correlate with long-term, cyclical changes in the Earth’s orbital relationship to the Sun. Three fundamental orbital relationships are involved, each of which contributes to the amount of sunlight received in high latitudes of the Northern Hemisphere. When these cycles combine to reduce the incoming solar radiation (insolation) during summer months, over a number of years, the ice sheets which permanently cover Greenland, parts of Alaska, northern Canada, Scandinavia, and elsewhere, begin to advance.
At a certain point, the growth process becomes self-feeding, partly because the high reflectivity of ice and snow reduces the local temperature, partly for reasons that are not fully understood. The glaciers thicken and expand until they become continental ice sheets, one to two miles thick, creeping ever southward. Geological evidence shows that in the last Ice Age, the southern boundary of the continental ice sheet, known as a terminal moraine, stretched down the center of Long Island, through New York City, across New Jersey and Pennsylvania to Southern Illinois and Missouri, then up the Plains States through Montana and Washington State. All of this real estate was buried under one to two miles of ice.
Geologically and climatologically speaking, we are due for another such glacial advance. It might not happen in our lifetimes, but radical shifts in the climate of northern regions can take place suddenly, and in some places may already be taking place.
Some of the indicators:
• Since 1980, there has been an advance of more than 55% of the 625 mountain glaciers under observation by the World Glacier Monitoring group in Zurich. (From 1926 to 1960, some 70-95% of these glaciers were in retreat.)
• A comparison of the U.S. Department of Agriculture’s 1965 and 1990 Plant Hardiness Zone Maps, shows a southward change of one zone, or 10°F, between 1965 and 1990.
• Careful measurements of the oxygen isotope ratios in German oaks, which are rigorously calibrated to temperature data, show a 1°C temperature decline from 1350 to 1800 (the lowpoint of the Little Ice Age). Temperature thereafter increased by 1°C from 1800 to 1930, and has been declining since then.
• From weather stations in the Alps, and in the Nordic countries, we find the temperature decline since 1930 is also 1°C.
• Satellite measurements have shown growth in the height and breadth of the huge Greenland ice sheet, the largest in the Northern Hemisphere
That brings us to the Nisqually glacier, up on the 14,410-foot Mount Rainier, near Tacoma, Wash. Just 85 feet shy of Mount Whitney, the highest point in the lower 48 states, Mount Rainier has 26 glaciers, and is the largest single peak system in the United States.
In 1931, fearful that the receding glacier would provide insufficient runoff for their newly completed hydroelectric facility, Tacoma City Light began careful measurements of the glacier. Since the mid-1800s, the glacier had receded about 1 kilometer. Annual to semi-annual measurements, continued by the U.S. Geological Survey and private contractors for the National Park Service, provide the longest continuous series of glacier measurements in North America.
The details are described in a report by government specialists, which appeared in the September 2000 issue of Washington Geology:
“The greatest thickening during the period of measurement occurred between 1931 and 1945, when the glacier thickened by about 50% near 2,800 meters of altitude. This and subsequent thickenings during the mid-1970s to mid-1980s produced waves that advanced its terminus. Glacier thinning occured during intervening periods. Between 1994 and 1997, the glacier thickened by 17 meters at 2,800-m altitude, indicating probable glacier advance during the first decade of the 21st century.”
That’s the story from Mount Rainier. Retired geologist Sauers, who has been observing conditions in the Cascade Mountains of western Washington for a lifetime, says “I’m preparing for an Ice Age.” Perhaps we all should.