GLIMS Workshop 2004, Oslo, Norway: Agenda
Human Impacts of Rapid Glacier Responses to Global Climate Change
A multinational consortium of scientists is meeting this week in Oslo,
Norway, to discuss glacier responses to global climate change and other
non-climate-related forcings. There is general agreement within the group,
called GLIMS (Global Land Ice Measurements from Space), that glaciers in
most parts of the world are continuing a fast-paced retreat phase and that
global climate changes are the underlying forcing factor. The practical
impacts are profound and relate directly to people in many countries.
However, the patterns of global climate change and glacier responses are
complex and variable from region to region. The GLIMS meeting is being
held to recognize the complexities and arrive at a better understanding of
why regional differences in glacier responses exist. A public forum on
recent GLIMS results and future directions will be held in Oslo from 2-3 PM
on August 20 at Norwegian Water Resources and Energy Directorate,
Middelthuns gate 29, Oslo. Three speakers will look at glacier changes and
impacts occurring in: (1) Norway (Rune Engeset, Norwegian Water Resources
and Energy Directorate), (2) both polar regions (Gordon Hamilton,
University of Maine), and around the world (Jeffrey S. Kargel, U.S.
Geological Survey, Flagstaff, Arizona). The International Glaciological
Society (IGS) will be holding a separate but related meeting, in Geilo,
Norway, next week to discuss specifically the issue of glaciers in the
Arctic, where many ice caps are retreating and where complex and rapid
changes are occurring to the Greenland Ice Sheet.
The GLIMS consortium is organized and led by the U.S. Geological Survey,
funded through NASA and other funding and research agencies around the
world, and is being carried out in direct cooperation with the Zurich-based
World Glacier Monitoring Service (WGMS). GLIMS is using primarily
satellite-based cameras, notably ASTER (a Japanese camera flying aboard an
America satellite, Terra) to track changes to the world's glaciers. In
addition, traditional field-based methods of glacier monitoring are being
used to validate the satellite image analysis and to extend the satellite
studies to include measurements that can only be made from the ground.
While ASTER is providing what amounts to a snapshot of the world's glaciers
in the early 21st century, topographic maps, air photos, field glaciology
data, and older satellite images provide a key storehouse of information
allowing a long time series of glacier changes to be amassed in many
regions of the world.
Most scientists in the consortium are reporting evidence for retreat or
vertical downwasting and loss of ice mass in most glaciers within their
regions of study. Glaciers in the United States, in Himalayan nations, the
European Alps, and many other regions are undergoing rapid and even
accelerating decay. The collapse or partial collapse of several ice
shelves and acceleration of land-based glaciers in Antarctica and Greenland
point out complex trigger mechanisms that first induce ice shelves to break
apart and then cause the ice that once fed those ice shelves to drain more
rapidly. Enhanced rates of melting are the underlying cause. There are
other regions, notably Norway, where the patterns are more complex: some
glaciers have been advancing while others have been retreating. Some
tidewater glaciers in Alaska are experiencing dramatic fluctuations,
including some glaciers that have made news-worthy advances, though the
great majority continue a pattern of decay that has characterized the last
century. Land-terminating surging glaciers are also common in some
regions, such as in Alaska and Svalbard (Arctic Ocean); these complicate
the analysis of the global record of glacier changes. The cases of
surging, advancing, or stable glaciers have to be examined case by case for
special mechanisms that explain their advance in a general global
environment where the great majority of glaciers are shrinking. In some
cases, as in Norway, the advancing or stable glaciers are made
comparatively healthy because of recent increases in the supply of moisture
from the ocean, and consequently larger than normal amounts of snow
accumulation. In coastal regions of Scandinavia this effect has balanced
the effect of increased mean temperatures. Glaciers in the interior of
Scandinavia are more affected by the recent high summer temperatures and
the effects of increased melt. Since 2001, very high mass losses have been
observed. Climate scenarios for the region suggest increasingly large net
loss of ice and thus further glacier retreat. The Norway anomaly is thus
consistent with global climate models that consider various scenarios for
future increases in greenhouse gases due to human activities and natural
processes. These same climate models highlight certain regions where the
next few decades will see both sharp increases in temperature and
decreasing or stable rates of precipitation, thus guaranteeing
exceptionally rapid decay of their glaciers. Chile (north of Patagonia)
and Afghanistan and other parts of central Asia are two such areas.
These latest findings extend observations made over the decades by
glaciologists around the world and extend the results compiled in sources
such as the USGS series Satellite Image Atlas of the World and the
Zurich-based World Glacier Monitoring Service's series of Glacier Mass
Balance Bulletins. The GLIMS data, using an evolution of measurement
parameters established by WGMS, are being compiled and assessed through the
National Snow and Ice Data Center (Boulder, Colorado, USA), while
individual regional analyses are being conducted by individual scientists
and through the global GLIMS consortium involving over 25 countries. GLIMS,
the USGS Cryosphere program, and the WGMS are operating within a framework
established by the Global Terrestrial Observing System's (GTOS)
Glacier-Network (GTN-G), established to support the goal of achieving
sustainable development. GLIMS employs satellite and supporting ground
observations to expand so-named "tier-5" coverage within the terrestrial
observing system's strategy. The first formal and extensive printed
compendium of GLIMS results will be presented in a future book being
organized at the GLIMS meeting in Oslo.
The practical impacts of changing glaciers on water supplies, agricultural
production, human well being, political stability, and natural ecosystems
are, like the climate forcings, very complex and regionally varied; they
are made even more complex by the uneven distribution of population and
wealth, national borders and international and ethnic cultural differences,
and by regional armed conflicts. Already, there have been significant
impacts on human activity and natural ecosystems in areas affected by the
last century of glacier change. For the following discussion, the IPCC SRES
A2 model is used as a middle-estimate baseline climate model, though most
other models give qualitatively similar patterns.
HYDROPOWER. Looking toward the next 50-100 years, climate projections
reported by the IPCC, coupled with recent regional changes in glaciers,
give a good idea of where we can expect rapid changes in glacier ice mass
and dynamics. In some regions, such as Norway and Iceland, increasing
precipitation and rising glacier meltwater production will drive increasing
potential for hydropower generation at least for the next 50 years;
however, a very recent sudden trend toward glacier recession in Norway
suggests that glaciers might become less significant as a component source
of water runoff, such that seasonality of runoff may increase. IPCC
climate projections for some other regions, such as the European Alps and
the Andes in Peru, Bolivia, and Chile north of Patagonia, disappearing
glaciers might contribute to a reduction of hydropower potential and force
an increasing reliance on artificial reservoirs to supply water to urban
centers and agricultural lands.
REGIONAL POLITICAL STABILITY AND GLOBAL SECURITY. IPCC projections for
Central Asia, already desperately dependent on glacier meltwater, will see
most glacier sources of economic viability largely disappear, thus
furthering a regional drought that already has been linked to agricultural
failure and two decades of unstable political dynamics in Afghanistan. The
IPCC climate projections and recent trends in glaciation suggest that
Kashmir, Pakistan, Uzbekistan, and even Tajikistan and Kyrgyzstan will
suffer increasing water deprivation as precipitation falls, temperatures
rise, and glaciers tend to disappear gradually over the 21st century.
Thus, regional and global security issues will be linked increasingly to
glacier mass balance and anthropogenic/natural climate change in Central
Asia. In regions farther east in Asia, the critical role of the changing
monsoon must be understood as a cause of accumulation of glaciers in the
eastern and central Himalaya, which could become a principle water source
for Central Asia, supplementing the glaciated mountains of Kyrgyzstan as a
source of water for parched nations such as Uzbekistan. Regional
engineering water works, if they can be designed to avoid the environmental
crises such as that which has plagued the Aral Sea drainage basin since the
Soviet era, may be required to deal with increasingly arid conditions and a
change of seasonality of water availability caused by melting and gradual
disappearance of glaciers from Central Asia. However the hydrological
problems will be solved in Central Asia and elsewhere, it will be necessary
to understand the roles of natural and anthropogenic climate change on
glacier mass balance if regional water issues are to be dealt with and
progress and peace are to replace political instability that may reasonably
be predicted in the absence of knowledge and planning.
ECOSYSTEMS. In many mountainous arid regions, such as western China, Peru,
and the "stans," receding alpine glaciers will cause a deterioration of
desert riparian ecosystems and agriculture in glacier-watered valleys. In
more humid alpine regions, such as in Alaska and parts of the Himalaya,
receding glaciers will open new alpine valleys, passes, and peaks for
expansion of adjacent ecosystems or human exploitation. In presently
heavily glaciated mountains, opening of key mountain passes and clearing of
ice from valleys may cause increasing genetic integration of currently
isolated populations of land-lumbering mammals.
GLACIER HAZARDS. The general wastage of glaciers in the Himalaya, European
Alps, Andes, Caucasus, Cascades, and Alaskan mountain ranges will cause
shifting patterns of glacier hazards due to glacier lake outburst floods,
ice avalanches, volcanic lahars, and ice damming of rivers.
(1) GLOFs: The types of unstable moraine-dammed lakes and
supraglacial lakes-- and the attendant glacier lake outburst flood (GLOF)
hazards-- that are so characteristic in Bhutan and Nepal will likely become
more common among wasting valley glaciers of Tajikistan, Pakistan, Indian
and Pakistani sectors of Kashmir, and Kyrgyzstan. A characteristic Alaskan
style of ice marginal lake formed where tributary glaciers detach from main
trunk glaciers will likely also become common throughout the Himalaya and
the Tien Shan, thus presenting a relatively new type of GLOF hazard in
those regions. In Alaska, ice marginal and supraglacial and moraine-dammed
lakes will continue to be a major hazard, but some lakes will disappear and
other develop as glaciers continue a long trend of retreat and wasting. In
some regions, such as Peru and the European Alps, where once-mighty
glaciers have already wasted to small remnants, lingering GLOF hazards will
progressively diminish and disappear.
(2) SURGES. Surging glaciers will remain common in Alaska, but the
maximum extent of their surge fronts, and hence the infrastructural threat
posed by these glaciers will tend to recede as the glaciers themselves lose
mass over the long term. However, development will have to take into
strict account the evolving hazards posed by surge-type glaciers.
(3) ICE-DAMMED RIVERS. Another type of glacier hazard-- the
glacier-dammed river-- is generally becoming less widespread and less
severe around most of the world, wherever glaciers are receding. However,
there remain very substantial dangers of this happening, for instance near
Namche Barwa (7782m, Tibetan Himalaya), which has a glacier today that
nearly dams the Yarlong Tsangpo River. In the recent past (1250 yr) this
river has been dammed deeply two or more times by glaciers; in 750 AD it
made a dam 600 ft high. Because this mountain is in the zone of monsoonal
influence, it is possible that despite rising temperatures, increasing snow
accumulation may cause the re-advance and redamming of the river. The slim
but real potential still exists whereby the Delta River in Alaska could be
dammed by glacier surges, thus flooding the Alyeska Pipeline and Richardson
Highway. The Copper River, Alaska, also could be dammed by glacial
re-advances; however the actual likelihood of this every happening again is
remote because the glaciers are losing mass at this time and probably will
continue to do so.
(4) ICE AND GLACIER DEBRIS AVALANCHES. Another type of glacier hazard
includes the destabilization of ice-cored moraines and thawing of the beds
of hanging glaciers, which can cause ice and debris avalanches, such as
that which killed over 100 people in the Russian Caucasus in 2002. This
type of hazard will increase dramatically in some regions, as glacier
downwasting removes support for high moraines, as climate warming thaws ice
cementing these moraines, and as warming thaws and loosens hanging glacier
ice from steeply sloping mountain bedrock.
(5) LAHARS. The threat of lahars due to volcano-glacier interactions
may diminish as the ice load melts and reduces the amount of ice available.
However, this very unloading process potentially can induce volcanic
eruptions. The hazard of lahars threat does not disappear until glaciers
are completely eliminated from a volcano's summit and flanks.
SEALEVEL. Outstanding questions remain about ice sheet mass balance in
Greenland and Antarctica, but the latest indications are that the balance
might have recently shifted to negative from a state of near balance; it
is something that will be watched very closely by the global glaciological
community. Small ice caps and subpolar glaciers contribute significantly
to sea level rise and will continue to do so. Sealevel rise in the 21st
century is projected to be about 0.11 to 0.77 m (4 to 30 inches) and will
include a substantial component due to melting land ice. Sea level rise
toward the upper end of this scale will pose serious issues for coastal
cities, barrier islands, deltaic agriculture, and coastal wetlands.
SUMMARY. Glacier changes include both beneficial and deleterious effects
for humans. The benefits and losses are disparate around the globe. It is
difficult to integrate and quantify the net effect on human welfare and
global planetary health, but this integration is an important objective for
the future. However, judged from fundamentals, it would seem that any
massive, rapid changes in the Earth system, such as that now affecting the
cryosphere, on the whole are destabilizing to natural ecosystems and human
economies and political structures. While the Earth system tends to be
resilient on the long term, especially for slow changes, such resiliency
and rebound often occurs at the terrible expense of entire species. Humans
should not assume that it will be the Earth's other species, or any
particular group of other nations, that will pay the entire price of
unintended consequences of glacier change caused by climate changes and of
human activities that are accelerating those changes.
CONTACTS FOR THIS PRESS RELEASE:
Global changes:
Dr. Jeffrey S. Kargel, U.S. Geological Survey GLIMS project
coordination,
Flagstaff, AZ86001, USA, email1: jkargel@usgs.gov,
email2:jeffreyskargel@hotmail.com, telephone1: +1 (928) 556-7034,
telephone2: +1 (928) 527-4196, cell phone: +1 (928) 853-7795.
Dr. Richard S. Williams, U.S. Geological Survey Cryosphere Program
manager, CONTACT INFO HERE
Dr. Bruce Molnia (Glaciers in Alaska), CONTACT INFO HERE
For additional expert assistance:
Dr. Alan Gillespie
W. M. Keck Remote Sensing Lab
Earth & Space Sciences 35-1310
University of Washington
Seattle, WA 98195-1310
206 685 8265
206 685 2379 fax
Dr. Andreas Kaab,
University of Zurich
Zurich, Switzerland
email: kaeaeb@geo.unizh.ch
Dr. Rune Engeset, Research Scientist. Norwegian Water Resources and Energy
Directorate. Box 5091 Maj., N-0301 Oslo, Norway. E-mail: rue@nve.no.
Telephone: +47 2295 9261. Cell phone: +47 99038868.
Internet resources:
GLIMS website: http://www.glims.org
Recent GLIMS powerpoint presentation: www.glims.org/Publications/
2004-March_ASTER-ScienceTeamPasadena/2004March-ASTER_SciTmPasadena-2.pdf
Glacier Network website: http://www.fao.org/gtos/gt-netGLA.html
WGMS site: http://www.geo.unizh.ch/wgms/index.html
Glacier Hazards website: http://www.geo.unizh.ch/gaphaz/home.html
USGS Cryosphere site:
http://geochange.er.usgs.gov/pub/poster/glacier.html
USGS Satellite Image Atlas site: http://pubs.usgs.gov/fs/fs133-99/
National Snow and Ice Data Center: http://nsidc.org/
Norwegian Water Resources and Energy Directorate: http://www.nve.no
Intergovernmental Panel on Climate Change: http://www.ipcc.ch/
Global climate change resources:
J.T. Houghton et al. (Editors), Climate Change 2001: The Scientific
Basis, Published for the Intergovernmental Panel on Climate Change,
Cambridge University Press, 2001.
Supporting graphics (one page each, to be linked through GLIMS website):
Figure 1: Global map showing locations of collaborating GLIMS
institutions
Figure 2. A century of glacier retreat in the Chugach Mountains, Alaska
Figure 3. Vertically wasting, but stably positioned glaciers in the
Himalaya