Geologist Maynard Miller sees the Juneau Icefield as the canary in the mine of global warming, chirping a loud warning.
"What happens on Andes glaciers and in Patagonia parallels what is happening here," he said.
Miller is convinced that the 5,000-square-mile icefield is a harbinger of changes to come around the world as a result of what many know as "the greenhouse effect," the warming of the earth and its lower atmosphere caused by solar radiation trapped by carbon dioxide.
"We are not just looking at the Mendenhall and 37 other big glaciers," said Miller, founder of the Juneau Icefield Research Program and a professor with the Glaciological and Arctic Sciences Institute at the University of Idaho.
"It's the fifth largest icefield in the western hemisphere. We are looking at trends that are globally significant."
Every summer since 1946, Miller has visited Juneau to collect icefield data. More than 1,000 papers and professional reports have been produced by students accompanying him in the program, helping resolve the complex link between glacial behavior and climate change.
Miller's study has revealed, for example, that the Lemon Creek Glacier has receded substantially since 1759. It has also revealed that the Lemon Creek Glacier's surface has dropped overall by about 82 feet from 1953 to 1999. In 1996 and 1997, no new snow was retained on its surface.
"Maynard probably has more specific knowledge about global warming in Juneau than anyone else because of his 50 years of research," said Scott Foster of the University of Alaska Southeast. Miller is a visiting fellow with the UA system.
The public has been slow to accept climatic change as scientists see it, Miller said.
"Fifty years ago, people didn't know what you were talking about. But when I made the first American ascent of St. Elias (67 miles northwest of Yakutat) in 1946, I saw the remarkable recession of the ice in Icy Bay. That got me interested, and I picked an area that was prototypical, the Juneau Icefield."
Miller is not alone in his concern. The U.S. Environmental Protection Agency and the Forest Service also are studying the phenomenon of global warming, changes in climate believed to be due to human activity such as burning fossil fuels.
During the 20th century, the EPA says, the average temperature in Anchorage increased by 3.9 degrees Fahrenheit, from 30.6 to 34.5 degrees. And, over the last 41 years of available data, precipitation has increased by about 10 percent in many parts of Alaska.
"These past trends may or may not continue into the future," according to the EPA's Web site.
Over the years, Miller and 30 to 50 students per season have installed 12 weather stations and made 5,000 aircraft sorties, plus trips on over-snow vehicles. During the Cold War, the federal government considered the research applicable only to whether periscopes could pierce the pack ice in the Arctic, Miller said. Russia's launching of Sputnik in 1962 pressured the United States to encourage more careers in science, and the National Science Foundation began funding Miller. Lately, NASA has opened its wallet.
"The Arctic is the most acutely sensitive region in the world in terms of climate changes, because of the sea ice and permafrost. For the first time in 100 years, last summer there was open water at the North Pole," Miller, 80, said. "Things are changing fast."
"We don't have to prove global warming exists any more. We now know it can affect growing corn in East Africa and floods on the Mississippi and in Mozambique. We must maintain monitoring of these glaciers as total fields - not just receding faces," Miller said. "We need to monitor the intensity and rapidity of changes on this (icefield) system."
According to the Environmental Protection Agency's Web site on global warming, sea level is rising more rapidly along the U.S. coast than worldwide. Studies by EPA and others estimate that a 1-foot rise in sea level along the Atlantic and Gulf coasts is likely by 2050 and could occur as early as 2025. Sea level will probably continue to rise for several centuries, even if global temperatures were to stop increasing a few decades hence.
Direct geographical impacts of sea level rising include loss of beaches and beach properties, ecologically productive wetlands that harbor shrimp and waterfowl, and barrier islands that help shield the mainland from storm surges. Indirect economic impacts include loss of revenue from tourism, reduced property values and increased costs for repairing infrastructure, such as coastal roads damaged by storm surges, according to the EPA.
Southeast Alaska, however, has an unusual "resource," called glacial rebound, to battle rising seas, said Chris Meade, a forester with the EPA's Juneau office. Land here rises slowly as glaciers shrink and lower the huge amount of weight they place on the Earth's crust, which is essentially floating on a layer of molten rock.
"Southeast Alaska is likely to buck the national trend. Sea level will rise in most of the United States but will actually fall in Southeast because, as glaciers recede, the land tends to rebound as the weight of the glaciers is lifted," Meade said.
The Mendenhall Wetlands are rising about 0.34 inch every 10 years, said Ben Kirkpatrick, a Juneau employee of the Habitat and Restoration Division of the Alaska Department of Fish and Game.
The EPA estimates sea level may rise a total of 10 inches by 2100 along much of Alaska's coast. But the agency estimated the rate of uplift would match or exceed the effects of climate change.
A separate study by the National Oceanic and Atmospheric Administration says the annual trend in Juneau from 1950 to 1986 is a lowering of the sea level by about half an inch.
The level of certainty about what will happen to the climate in the next 50 or 100 years is low, Meade said. Scientific climate records have been kept in most of Alaska for fewer than 150 years, making "averages" and long-range conclusions suspect.
"It's not all negative," he said. "Canada might actually benefit in an agricultural sense from a warmer climate. Pacific Northwest forests might benefit because of greater growth during warmer summers. Salmon spawning streams might be more productive so we would have greater number of smolts - but then we don't know what conditions would be like for them when they reach the ocean."
Meade believes global warming will have "a bigger impact on Arctic Alaska as it changes the ice pack, permafrost and sea life" than it will have on Southeast Alaska.
"We already have a wet and cool climate and are sheltered somewhat from changes by maritime influences. Of course, there might be more rain," he said.
Ann Chandonnet can be reached at achandonnet@juneauempire.