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THE ICE IS MELTING
Chapter 2. Signs of Stress: Climate and Water
Lester R. Brown, Eco-Economy: Building an Economy for the Earth
(W.W. Norton & Co., NY: 2001).
Ice melting is one of the most visible manifestation
of global warming. Sometimes the evidence that mountain glaciers
are melting takes novel forms. In late 1991, hikers in the southwestern
Alps on the Austrian-Italian border discovered an intact male human
body protruding from a glacier. Apparently trapped in a storm more
than 5,000 years ago and quickly covered with snow and ice, his
body was remarkably well preserved. In 1999, another body was found
in a melting glacier in the Yukon Territory of western Canada. As
I noted at the time, our ancestors are emerging from the ice with
a message for us: the earth is getting warmer.13
In the Arctic Ocean, sea ice is melting fast. As recently as 1960,
the Arctic sea ice was nearly 2 meters thick. In 2001, it averaged
scarcely a meter. Over the last four decades, the ice sheet has
thinned by 42 percent and it has shrunk in area by 6 percent. Together,
this thinning and shrinkage have reduced the Arctic Ocean ice mass
by nearly half. This rapid melting is expected to continue. A recent
study by two Norwegian scientists projects that within 50 years
the Arctic Ocean could be ice-free during the summer.14
In 2000, four U.S. scientists published an article in Science
reporting that the vast Greenland ice sheet is starting to melt.
Lying largely within the Arctic Circle, Greenland is gaining some
ice in higher elevations on its northern reaches, but it is losing
much more at lower elevations, particularly along its southern and
eastern coasts. This huge island of 2.2 million square kilometers
(three times the size of Texas) is experiencing a net loss of 51
billion cubic meters of water each year, an amount approaching two
thirds of the annual flow of the Nile River as it enters Egypt.15
The Antarctic peninsula is also losing ice. In contrast to the North
Pole, which is covered by the Arctic Sea, the South Pole is covered
by the continent of Antarctica, a land mass roughly the size of
the United States. Its continent-sized ice sheet, which is on average
2.3 kilometers (1.5 miles) thick, is relatively stable. But the
ice shelves, the portions of the ice sheet that extend into the
surrounding seas, are fast disappearing.16
A team of U.S. and British scientists reported in 1999 that the
ice shelves on either side of the Antarctic peninsula are in full
retreat. From roughly mid-century through 1997, these areas lost
7,000 square kilometers as the ice sheet disintegrated. But then
within scarcely one year they lost another 3,000 square kilometers.
Delaware-sized icebergs that have broken off are a threat to ships
in the area. The scientists attribute the accelerated ice melting
to a regional temperature rise of 2.5 degrees Celsius (4.5 degrees
Fahrenheit) since 1940.17
These are not the only examples of melting. Lisa Mastny of Worldwatch
Institute, who reviewed some 30 studies on this topic, reports that
mountain glaciers are melting worldwide-and at an accelerating rate.
(See Table 2-1.) The snow/ice mass is shrinking in the world's major
mountain ranges: the Rocky Mountains, the Andes, the Alps, and the
Himalayas. In Glacier National Park in Montana, the number of glaciers
has dwindled from 150 in 1850 to fewer than 50 today. The U.S. Geological
Survey projects that the remaining glaciers could disappear within
30 years.18
In Europe's Alps, the shrinkage of the glacial volume by more than
half since 1850 is expected to continue, with these ancient glaciers
largely disappearing over the next half-century. Shrinkage of ice
masses in the Himalayas has accelerated alarmingly. In eastern India,
the Dokriani Bamak glacier, which retreated by 16.5 meters between
1992 and 1997, drew back by a further 20 meters in 1998 alone.19
A research report by Lonnie Thompson of Ohio State University indicates
that the ice cap on Kilimanjaro could disappear within 15 years.
This upset Tanzania's Minister of Tourism, Zokia Meghji, who told
parliament that the projected melting was exaggerated, as he tried
to allay fears about the effects on the country's lucrative tourism
industry. In response, Thompson pointed out that his report was
simply based on an extrapolation of the recent historical trend.20
Researchers are discovering that a modest rise in temperature of
1-2 degrees Celsius in mountainous regions can dramatically alter
the precipitation mix, increasing the share falling as rain while
decreasing the share coming down as snow. The result is more flooding
during the rainy season, a shrinking snow/ice mass, and less snowmelt
to feed rivers during the dry season.21
These "reservoirs in the sky," where nature stores fresh water for
use in the summer as the snow melts, have been there ever since
irrigation began, supplying farmers with water for several thousand
years. Now suddenly, in a matter of years, they are shrinking and
some could disappear entirely, sharply reducing the water supply
for irrigation and for cities.
If the massive snow/ice sheet in the Himalayaswhich
is the third largest in the world, after the Antarctic and Greenland
ice sheetscontinues
to melt, it will affect the water supply of much of Asia. All of
the region's major riversthe
Indus, Ganges, Mekong, Yangtze, and Yelloworiginate
in the Himalayas. Melting in this area could alter the hydrology
of several Asian countries, including Pakistan, India, Bangladesh,
Thailand, Viet Nam, and China. Less snowmelt in the summer dry season
to feed rivers could worsen the hydrological poverty already afflicting
so many in the region.22
We don't have to sit idly by as this scenario unfolds. There may
still be time to stabilize atmospheric CO2 levels before carbon
emissions lead to unmanageable climate change. There is an abundance
of wind, solar, and geothermal energy to harness for running the
world economy. (See Chapter 5.) If we were to cut income taxes and
offset this by incorporating a carbon tax that reflected the cost
of climate disruption in the price of fossil fuels, investment would
quickly shift from fossil fuels to these climate-stabilizing energy
sources.
| Table 2-1. Selected Examples of Ice Melt
Around the World |
| Name |
Location |
Measured
Loss |
|
|
|
| Arctic
Sea Ice |
Arctic
Ocean |
Has
shrunk by 6 percent since 1978, with a 14-percent loss
of thicker, year-roundice. Has thinned by 40 percent in
less than 30 years. |
| Greenland
Ice Sheet |
Greenland |
Has
thinned by more than a meter a year on its southern and
eastern edges since 1993. |
| Glacier
National Park |
Rocky
Mtns., United States |
Since
1850, the number of glaciers has dropped from 150 to fewer
than 50. Remaining glaciers could disappear completely
in 30 years. |
| Larsen
B Ice Shelf |
Antarctic
Peninsula |
Calved
a 300-square-kilometer iceberg in early 1998. Lost 1,714
square kilometers during the 1998-99 season, and 300 square
kilometers during the 1999-2000 season. |
| Dokriani
Bamak Glacier |
Himalayas,
India |
Retreated
by 20 meters in 1998, compared with 16.5 meters over the
previous 5 years. |
| Tien
Shan Mountains |
Central
Asia |
Twenty-two
percent of glacial ice volume has disappeared in the past
40 years. |
| Caucasus
Mountains |
Russia |
Glacial
volume has declined by 50 percent in the past century. |
| Alps |
Western
Europe |
Glacial
volume has shrunk by more than 50 percent since 1850.
Glaciers could be reduced to only a small fraction of
their present mass within decades. |
| Kilimanjaro |
Tanzania |
Ice
cap shrunk by 33 percent from 1989 to 2000. Could disappear
by 2015. |
| Quelccaya
Ice Cap |
Andes,
Peru |
Rate
of retreat increased to 30 meters a year in the 1990s,
up from only 3 meters a year; will likely disappear before
2020. |
|
| Source: Updated from Lisa Mastny, "Meling of Earth's
Ice Cover Reaches New High," Worldwatch News Brief (Washington,
DC: Worldwatch Institute: 6 March 2000). |
ENDNOTES:
13. John Noble Wilford, "Move Over, Iceman! New Star From the Andes,"
New York Times, 25 October 1995; James Brooke, "Remains of Ancient
Man Discovered in Melting Canadian Glacier," New York Times, 25
August 1999.
14. Lisa Mastny, "Melting of Earth's Ice Cover Reaches New High,"
Worldwatch News Brief (Washington, DC: 6 March 2000); Wilford, op.
cit. note 1; 50-year projection in Lars H. Smedsrud and Tore Furevik,
"Towards an Ice-Free Arctic?" Cicerone, no. 2, 2000.
15. W. Krabill et al., "Greenland Ice Sheet: High Elevation Balance
and Peripheral Thinning," Science, 21 July 2000, p. 428; usable
flow of the Nile River is 74 billion cubic meters, according to
Sandra Postel, Pillar of Sand (New York: W.W. Norton & Company,
1999), pp. 71, 146.
16. "Melting of Antarctic Ice Shelves Accelerates," Environmental
News Network, 9 April 1999.
17. Ibid.
18. Mastny, op. cit. note 14.
19. Ibid.
20. Lonnie G. Thompson, "Disappearing Glaciers Evidence of a Rapidly
Changing Earth," American Association for the Advancement of Science
annual meeting proceedings, San Francisco, CA February 2001; response
by Zakia Meghji in "Newswire," New Scientist, 26 May 2001.
21. Christopher B. Field et al., Confronting Climate Change in California:
Ecological Impacts on the Golden State (Cambridge, MA: Union of
Concerned Scientists, 1999), pp. 2-3, 10.
22. Robert Marquand, "Glaciers in the Himalayas Melting at Rapid
Rate," Christian Science Monitor, 5 November 1999.
Copyright
© 2001 Earth Policy Institute
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