Glacier Expert Joins Colleagues Documenting Loss of World's Ice

Feb. 16, 2006

Newswise — Changes in glaciers in the world's largest and highest mountain system may have the most immediate effects on nearly half of the world's population, a University of Idaho glaciologist said here Thursday.

Vladimir Aizen, a UI professor of glaciology, said changes in the flow of freshwater from 100,000 glaciers in the Central Asia Mountain System will affect nearly 2.5 billion people.

He spoke at a media briefing organized by the American Association for the Advancement of Science during its annual meeting in St. Louis.

Rising temperatures are causing dramatic changes in the world's glaciers, scientists studying ice fields in Greenland, Chile and Asia agreed during the briefing.

Aizen said changes in water flow caused by climate change could have dramatic influence on water supplies.

Better information is needed about both the record of past climate shifts stretching back 200,000 years recorded in Central Asia's mountain glaciers, Aizen said. That data can guide future decisions and trillions of dollars of investment to build reservoirs or other means of coping with changing water regimes.

Aizen said rising temperatures can be expected to narrow the time between the rivers' annual peaks of runoff from rain and snow and the historically later peak of glacial meltwater. The delay kept river flows higher for a longer period each summer.

Narrowing the runoff season creates larger, more damaging mountain floods that will last for shorter times, outstripping the capacity of many hydropower and irrigation systems to parcel the water out for agriculture and lengthening the arid season.

The U.S. Department of Energy funded Aizen to begin preliminary studies of changes in snowpack in central Idaho's rugged Salmon River country. He has also conducted expeditions funded by the National Geographic Society, National Science Foundation and others to the Himalayas, Pamirs, Tibet and elsewhere in central Asia.

At St. Louis, NASA researcher Eric Rignot of the Jet Propulsion Laboratory said data gathered last year shows low elevation glaciers in Greenland are flowing two to three times faster than predicted. Rignot and University of Kansas researcher Pannir Kanagaratnam are scheduled to publish their study in the AAAS journal, Science, Friday.

The briefing Thursday touched on themes Aizen, Rignot and Gino Casassa of Chile's Centro de Estudios Cientificos will examine during a symposium Saturday titled "What?s Happening to All the World?s Ice?"

Aizen recently received a $500,000 grant from NASA to use historical records reaching back a century or more and satellite images from the 1970s to track changes in central Asia's ice.

Working closely with colleagues at the University of Maine, and internationally with colleagues from Japan, Germany, Switzerland, China and elsewhere, Aizen hopes to recover a one kilometer long ice core from Asia's Pamir Mountains.

That core will offer a highly detailed view of perhaps 200,000 years of climate records. Because the high mountains receive abundant snowfall, a chemical analysis of its layers can pinpoint seasonal variations thousands of years ago.

"This information will be critical in making decisions that will influence the fate of the world's most populous countries," Aizen said.

Mountain ranges including the Himalayas, Pamirs, Tien Shan, Altai and the Tibetan Plateau hold the largest volume of ice outside the polar icecaps. The icefields feed some of the world's great rivers including the Yangtse, Mekong, Ganges, Ob and Amur that influence people directly and indirectly.

The flows of the Yangtze, Ganges and Huang Rivers directly affect the water supply and well being of large populations. The shrinking Aral Sea is fed by the Amudarya and Sirdarya. The Ob and Yenisey River flows influence the Arctic Ocean and could alter its circulation, and with it, global patterns.

Other researchers recently reported data they said showed the Gulf Stream, which brings warm Caribbean waters to the North Atlantic and moderates Europe's climate, is slowing.