MELTING GLACIERS

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MELTING GLACIERS
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Global Warming

• According to the recent IPCC report, the mean
  global surface temperature has increased by
  0.74OC over the last 100 years (1906-2005)
• 11 of the 12 warmest years have been recorded in
  the past 12 years

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Findings of the IPCC Assessment Report (2007)

• There has been a significant decline in the
  mountain glaciers and snow cover, which has
  contributed to the increased sea levels
• From 1961 to 2003, the global mean sea level rose
  by 1.8 (0.5) mm per year
• The global temperature of the oceans increased by
  0.10oC from surface to depth of 700m from 1961-
  2003 and 80 of the heat added to the climate
  system is being absorbed by the ocean
• Other long term climatic changes that have been
  observed include extreme droughts, intensity of
  tropical cyclones, changes in the salinity of the
  ocean and wind patterns

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Changes in the precipitation pattern IPCC
Report (2007)

• Precipitation has significantly increased () in
  eastern North and South America, northern and
  central Asia and northern Europe
• There has been decline (-) in precipitation in
  the Mediterranean, some regions in southern Asia,
  southern Africa and Sahel

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Melting of the Greenland Ice Sheet

• According to NASA scientists, the Greenland ice
  sheet is melting faster than it is being
  replaced, contributing to sea level rise
• The loss of ice from Greenland doubled between
  1996 and 2005
• From 1996 to 2000, the largest acceleration and
  mass loss came from southeast Greenland
• From 2000 to 2005, the trend extended to include
  central east and west Greenland
• It is estimated that 69 per cent of the ice-mass
  loss in recent years came from eastern Greenland

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Greenland ice is declining faster than expected

• Between 2003 and 2005 the low coastal areas of
  Greenland lost 155 gigatons of ice per year due
  to excess melting while the high elevation
  interior gained 54 gigatons annually from excess
  snowfall
• Between 2004 and 2006, the rate of melting
  accelerated, with the massive ice sheet melting
  two and one-half times faster than the previous
  two-year period
• Greenland lost roughly 164 cubic miles of ice
  from April 2004 to April 2006more than the
  volume of the North American Great Lake Erie

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Greenland Ice Sheet

• Dramatic ice mass losses concentrated in the
  low-elevation coastal regions, with nearly half
  of the loss coming from southeast Greenland

NASA Earth Observatory
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Greenland Ice Sheet

• Greenland is now losing 20 percent more mass
  than it receives from new snowfall each year.

NASA Earth Observatory
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Greenland Ice Sheet
University of Colorado, CIRES
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Melting of ice in Greenland

• 2001-2003
• A significant increase in the melting area
  has been observed along the edge of the ice cap
  in Greenland.

NASA Earth Observatory
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Retreat of Ice and Snow in Greenland

• Ice loses in Greenland range from 5 to 25
  centimeters of water equivalent per year

NASA Earth Observatory
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Calving of Helheim Glacier, Greenland
The glaciers peak rate of flow has increased
from 8 km/yr in 2000 to 11 km/yr in 2005
Helheim glacier, located in southeast Greenland,
is now one of the fastest moving glaciers in the
world
1986-2006 These images show the retreat of
Helheim glaciers calving front

• This May 2005 picture of Helheim Glacier,
  demonstrates high calving activity associated
  with faster glacial flow

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Dramatic changes in Arctic Sea Ice
Imagine an ice-free Arctic
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Evidence of extensive snowmelts in West
Antarctica

• January 2005 Areas of extensive snowmelt (shown
  in yellow and red) have been discovered by a team
  of NASA and university scientists in response to
  warmer temperatures in west Antarctica .
• The combined area affected is as big as
  California.

NASA Jet Propulsion Laboratory
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Breakup of Larsen ice shelf (Antarctic Peninsula)
220 metres thick Larsen B shelf existed for at
least 400 years prior to breakup
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Disintegration of the Larsen B Ice Shelf,
Antarctic Peninsula

• The ice shelf disintegrated suddenly in March
  2002 due to warm summer temperatures

NASA Earth Observatory
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Breakup of Antarcticas Ross Ice Shelf

• An iceberg (B-15J) of size of a small United
  States state cracked off the Antarcticas Ross
  Ice Shelf in March 2000
• On February 1, 2007, three new icebergs were
  formed due to the break up of the original
  iceberg

NASA Earth Observatory
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Breaking Off Filchner Ice Shelf Antarctica
Filchner Ice Shelf is the largest ice shelf on
the planet
In 1986 the front edge of Ice Shelf broke off
into three enormous icebergs
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Calving of Ninnis Glacier Antarctica
22 January 2000 The Ninnis Glacier Tongue soon
after the initial calving
5 February 2002 Iceberg split into two sections
and started moving away from Ninnis Glacier
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Cracks on Drygalski Ice Tongue Antarctica
The ice tongue was discovered in 1902
21 February 2005 Drygalski calved an iceberg
Image shows cracks formed by time and ocean
currents
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Shrinking Lake Chad shared by Nigeria, Niger,
Chad and Cameroon
Persistent drought has shrunk the lake to about a
tenth of its former size

• 1972 Larger lake surface area is visible in
  this image

• 2001 Due to regionally drying climate and human
  demand for fresh water, Lake Chad is fraction of
  what is once was

• 2004 In many places, the green of wetlands is
  being replaced by drifting sand dunes (tan
  ripples mixed with green)

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Shrinking Breidamerkurjökull Glacier Iceland

• 1973-2000 Images show glacier has receded and
  the glacial lake at its tip has enlarged

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North America Angangueo
Ice dam in the Hubbard Glacier,United
States

• 1985 Hubbard Glacier

• 1986 Images show Degradation of forest area

• 1986 Hubbard Glacier blocks Russell Fjord

• 2001 Between 1984 and 1999, 38 per cent of
  forests were degraded

• 2002 Hubbard Glacier blocks Russell Fjord again
• 2003 Glacier has retreated

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Hubbard Glacier advances United States
North America Angangueo

• 1986 Images show Degradation of forest area

• 2001 Between 1984 and 1999, 38 per cent of
  forests were degraded

10 Aug 2002
14 Aug 2002
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North America Angangueo
Retreat of Columbia Glacier, Alaska and Arapaho
Glacier, Colorado, United States

• Since 1980, the Columbia glacier has retreated
  about 15 kilometers but its retreat has not been
  directly linked to rise in global temperatures
• Arapaho glacier has thinned by 40 meters since
  1960

• 1986 Images show Degradation of forest area

• 2001 Between 1984 and 1999, 38 per cent of
  forests were degraded

NASA Earth Observatory
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North America Angangueo
Athabasca Glacier, Canada

• Athabasca glacier has receded more than 1.5
  kilometres in last 125 years
• It has lost half of its volume

• 1986 Images show Degradation of forest area

• 2001 Between 1984 and 1999, 38 per cent of
  forests were degraded

NASA Earth Observatory

• About 8000 cubic kilometres of ice have been lost
  by glaciers worldwide since 1960.

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North America Angangueo
Glacier National Park, Montana, United States

• Only 37 glaciers exist compared to 147 glaciers,
  150 years ago

• 1986 Images show Degradation of forest area

• 2001 Between 1984 and 1999, 38 per cent of
  forests were degraded

10 Aug 1972-14 July 1974

• The glaciers are one-third their size in 1850
• Scientist predict that all the glaciers will
  disappear by 2030

7 July 2001
NASA Earth Observatory
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North America Angangueo
Glacier National Park, Montana, United States

• 1986 Images show Degradation of forest area

• 2001 Between 1984 and 1999, 38 per cent of
  forests were degraded

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North America Angangueo
Glacier National Park, Montana, United States

• 1986 Images show Degradation of forest area

• 2001 Between 1984 and 1999, 38 per cent of
  forests were degraded

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North America Angangueo
Ayles Ice Shelf, Ellesmere Island, Canada

• 1986 Images show Degradation of forest area

• 2001 Between 1984 and 1999, 38 per cent of
  forests were degraded

• Ayles Ice Shelf on Ellesmere Island, broke
  free on August 13, 2005 and drifted out to the sea

NASA Earth Observatory
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Declining Rwenzori Mountain Glaciers in East
Africa
This decline is attributed to increased air
temperature and decreased accumulation and
convective cloud activity
1987-2002 Images show a gradual decrease of the
glacial area, especially on the peaks
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Disappearing Icecap of Mt. Kilimanjaro, Tanzania
Africas highest mountain with a forest belt
having rich diversity of ecosystems

• 1976 Glaciers covered most of the summit

• 2000 The glaciers had receded alarmingly

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Retreat of Gangotri Glacier, India

• Gangotri glacier has retreated more than 850
  metres, in the last 25 years
• It has retreated more than 76 metres from 1996 to
  1999

NASA Earth Observatory
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Glacial Lakes and Glacial Lake Outburst Floods

• Glacial lakes are formed due to the melting of
  ice and snow from glaciers
• Due to the faster rate of melting from the
  glaciers, possibly due to global warming, water
  is accumulating at an increasing rate in these
  lakes
• Sudden outburst results in Glacial Lake Outburst
  Flood (GLOF) downstream causing destruction of
  life and property

Glacial Lakes in the Bhutan-Himalaya Region
Jeffrey Kargel, USGS/NASA JPL/AGU
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Retreat of Upsala Glacier, Argentina
January 2004 position

• The Upsala glacier has retreated more than 4
  kilometres since late 1960s to mid 1990s and
  continues to retreat

NASA Earth Observatory
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Retreat of San Quintin Glacier, Chile

• The San Quintin Glacier appears to be losing
  mass and retreating

NASA Earth Observatory
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MELTING GLACIERS
UNEP Atlas of Our Changing Environment
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