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 low-elevation 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

NASA Earth Observatory

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

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

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 glacier’s calving front

Calving of Helheim Glacier, Greenland

The glacier’s peak rate of flow has increased from 8 km/yr in 2000 to 11 km/yr in 2005

Dramatic changes in Arctic Sea Ice

Imagine an ice-free Arctic

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

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

North America: Angangueo

• 1986: Images show Degradation of forest area

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

Ice dam in the Hubbard Glacier,United States

• 1985 –Hubbard Glacier

• 1986 –Hubbard Glacier blocks Russell Fjord

• 2002 –Hubbard Glacier blocks Russell Fjord again

• 2003 – Glacier has retreated

North America: Angangueo

• 1986: Images show Degradation of forest area

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

Hubbard Glacier advances United States

14 Aug 2002

10 Aug 2002

North America: Angangueo

• 1986: Images show Degradation of forest area

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

Retreat of Columbia Glacier, Alaska and Arapaho Glacier, Colorado, United States

NASA Earth Observatory

• 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

North America: Angangueo

• 1986: Images show Degradation of forest area

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

Athabasca Glacier, Canada

• Athabasca glacier has receded more than 1.5 kilometres in last 125 years

• It has lost half of its volume

NASA Earth Observatory

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

North America: Angangueo

• 1986: Images show Degradation of forest area

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

Glacier National Park, Montana, United States

• The glaciers are one-third their size in 1850

• Scientist predict that all the glaciers will disappear by 2030

NASA Earth Observatory

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

10 Aug 1972-14 July 1974

7 July 2001

North America: Angangueo

• 1986: Images show Degradation of forest area

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

Glacier National Park, Montana, United States

North America: Angangueo

• 1986: Images show Degradation of forest area

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

Glacier National Park, Montana, United States

North America: Angangueo

• 1986: Images show Degradation of forest area

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

Ayles Ice Shelf, Ellesmere Island, Canada

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

1987-2002: Images show a gradual decrease of the glacial area, especially on the peaks

This decline is attributed to increased air temperature and decreased accumulation and 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

NASA Earth Observatory

• Gangotri glacier has retreated more than 850 metres, in the last 25 years

• It has retreated more than 76 metres from 1996 to 1999

Glacial Lakes and Glacial Lake Outburst Floods

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

Glacial Lakes in the Bhutan-Himalaya Region

Retreat of Upsala Glacier, Argentina

NASA Earth Observatory

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

January 2004 position

Retreat of San Quintin Glacier, Chile

NASA Earth Observatory

The San Quintin Glacier appears to be losing mass and retreating

UNEP Atlas of Our Changing Environment

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MELTING GLACIERS