Geologist: Icefield shows global warming

Posted: Friday, January 05, 2001

The glaciers of the Juneau Icefield have something to tell the world about global warming.

"We're on the edge of the best worldwide climate change indicator in the world, the Juneau Icefield," geologist Maynard Miller told about 80 people Thursday night at a Juneau World Affairs Council meeting at Dimond Courthouse. "Global warming is no longer an issue of contention, it's here."

Miller has drilled, blasted, measured and monitored the glaciers of the Juneau Icefield for more than 50 years, and what he's found - particularly on the Lemon Creek Glacier, offers insight into global weather patterns.

"Glaciers are the most delicate instruments for measuring climate change," he said. "And the Lemon Creek Glacier is a key glacier in this whole analysis."

Despite his experience, Miller has been wrong before. In the 1950s, after studying about 350 years of systematic global warming and cooling cycles, Miller and others predicted a worldwide cooling trend for the latter half of the 20th century. Miller identified a distinct warming and cooling pattern on 90-year cycles that has been consistent for hundreds of years. The coldest period of the 20th century was around 1910, and temperatures should have peaked in the 1950s and bottomed out in the late 1990s.

For decades, industry and many scientists pointed to this data to refute global warming. But instead of cooling, temperatures increased. Last year, scientists found previously unheard-of indicators of global warming such as open water at the North Pole.

Miller said conditions at the highest elevations of the Juneau Icefield are analogous to those at the North Pole. And last winter, instruments on the icefield recorded temperatures averaging about zero, 35 degrees warmer than normal.

"Natural climate trends have not taken over; they've been superseded by another effect that's not natural," Miller said.

Because Juneau is on the border between colder continental weather systems and warmer, moisture-laden maritime weather systems, a slight shift can have a profound effect. Miller and his researchers have found that the freezing levels have shifted over time to higher elevations, as is seen this year. Snowfall is heaviest at the freezing level, lighter at higher altitudes and falling as rain at lower levels. Snowfall is increasing now in different areas of the icefield than before, areas that feed the Taku Glacier, for example.

"The source areas that feed the Mendenhall, Eagle and Herbert glaciers are at lower elevation, and they're getting rain, not snow. So they're not getting fed," Miller said.

It's well documented that weather patterns are shifting all over the world, Miller said. That means spreading deserts in some areas, increased rainfall in others. In Northern Africa, Lake Chad has lost 95 percent of its water in the past 25 years. The Great Salt Lake in Utah has grown. Sea levels have risen and will continue to rise, Miller said.

"We're going to lose large parts of New Orleans, Boston, Bombay," Miller said. "Many of the great cities of the world."

The land in northern areas such as Juneau is rising, and this rebound and uplift may offset the rise in sea level, Miller said.

Deforestation and the increase of greenhouse gases such as carbon dioxide in the atmosphere are the cause, said Miller. Released by automobiles and industry, they aren't going to go away.

"Congress is not going to do anything about it. Our whole civilization depends on energy," Miller said. "The Kyoto conference (of 1997) asks to cut back (emissions) to 1990 levels. It's not going to happen."

Miller served eight years in the Idaho Legislature and said he's well acquainted with the political process. The reality, Miller said, is that a world hungry for energy will continue to demand it. The price of Alaskan oil may be down this week, but over the long term, Alaskans possess a valuable commodity. Alaska also has a wealth of potential hydroelectric power, a direction that may be more appealing in the near future.

France has the cleanest air in Europe, Miller said, the result of shifting away from burning coal and oil for energy. Instead, in 1978, the country went nuclear. The problem with nuclear energy is the waste, he said. The problem with burning hydrocarbons is irreversible atmospheric change.

Riley Woodford can be reached at

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