MELTING GLACIERS
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
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
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
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
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
2006—more than the volume of the North American Great Lake Erie
Greenland Ice Sheet
Dramatic ice
mass losses
concentrated
in the lowelevation
coastal
regions, with
nearly half of
the loss
coming from
southeast
Greenland
NASA Earth Observatory
Greenland Ice Sheet
Greenland is
now losing 20
percent more
mass than it
receives from
new snowfall
each year.
NASA Earth Observatory
Greenland Ice Sheet
University of Colorado, CIRES
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
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
Calving of Helheim Glacier, Greenland
The glacier’s peak rate
of flow has increased
Helheim
from 8 km/yr
glacier,
in 2000
located
to
in
11
southeast
km/yr in 2005
Greenland,
1986-2006:
These
isimages
now one
of the
show
thefastest
retreat
moving
glaciers
in the
of Helheim
glacier’s
world
calving front
 This May 2005 picture
of Helheim Glacier,
demonstrates high calving
activity associated with
faster glacial flow
Dramatic changes in Arctic Sea Ice
Imagine an
ice-free
Arctic
Evidence of extensive snowmelts in
West Antarctica
NASA Jet Propulsion Laboratory
•
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.
Breakup of Larsen ice shelf
(Antarctic Peninsula)
220 metres thick
Larsen B shelf
existed for at
least 400 years
prior to breakup
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
Breakup of Antarctica’s Ross Ice Shelf
• An iceberg (B-15J) of
size of a small United
States state cracked
off the Antarctica’s
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
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
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
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
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)
Shrinking Breidamerkurjökull Glacier
Iceland
• 1973-2000:
Images show
glacier has
receded and the
glacial lake at its
tip has enlarged
Ice dam in the Hubbard Glacier,
North America: Angangueo
United States
• 1985show
–Hubbard
• 1986: Images
Glacier
Degradation
of forest
area
• 1986 –Hubbard
Glacier blocks
• 2001: Between
Russell Fjord
1984
and 1999, 38 per cent
of forests
were –Hubbard
• 2002
degraded
Glacier blocks
Russell Fjord again
• 2003 – Glacier has
retreated
Hubbard Glacier
advancesAngangueo
United States
North America:
• 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
Retreat of Columbia
Glacier,Angangueo
Alaska and
North America:
Arapaho Glacier, Colorado, United States
•
Since 1980,
the Columbia
glacier
has
• 1986: Images
show
retreated
Degradationabout
of forest
15
kilometers but
area
its retreat has
not been
directly linked
to rise1984
in
• 2001: Between
global
and 1999, 38
per cent
temperatures
of forests were
• Arapaho
degraded
glacier has
thinned by 40
meters since
1960
NASA Earth Observatory
North America:
Athabasca
Glacier,Angangueo
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.
Glacier
National
Park, Angangueo
Montana,
North
America:
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
Glacier
National
Park, Angangueo
Montana,
North
America:
United States
• 1986: Images show
Degradation of forest
area
• 2001: Between 1984
and 1999, 38 per cent
of forests were
degraded
Glacier
National
Park,Angangueo
Montana,
North
America:
United States
• 1986: Images show
Degradation of forest
area
• 2001: Between 1984
and 1999, 38 per cent
of forests were
degraded
NorthEllesmere
America: Island,
Angangueo
Ayles Ice Shelf,
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
Declining Rwenzori Mountain Glaciers
in East Africa
This
declineImages
is
1987-2002:
attributed
to increased
show a gradual
air
temperature
decrease
of the and
glacial
decreased
area, especially on the
accumulation
and
peaks
convective cloud
activity
Disappearing Icecap of
Mt. Kilimanjaro, Tanzania
Africa’s highest mountain
with a forest belt having
rich diversity of
ecosystems
• 1976: Glaciers covered
most of the summit
• 2000: The glaciers had
receded alarmingly
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
Glacial Lakes and Glacial Lake
Outburst Floods
Glacial Lakes in the Bhutan-Himalaya Region
Jeffrey Kargel, USGS/NASA JPL/AGU
•
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
Retreat of Upsala Glacier, Argentina
January 2004 position
The Upsala glacier has retreated more
than 4 kilometres since late 1960’s to
mid 1990’s and continues to retreat
NASA Earth Observatory
Retreat of San Quintin Glacier, Chile
The San Quintin Glacier appears
to be losing mass and
retreating
NASA Earth Observatory
MELTING GLACIERS
UNEP Atlas of Our Changing Environment
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