These can burst their ice and soil dams
sending walls of water down valleys at speeds close to that of a modern
anti-tank missile.
Rising temperatures and the thawing of
frozen land or 'permafrost' is triggering the expansion of existing- and the
emergence of new- water bodies in places like Siberia.
These are bubbling methane into the
atmosphere with emissions so forceful they can keep holes open on the lakes'
icy surfaces even during sub zero winter months.
Methane is a powerful global warming gas
and new estimates indicate that the quantities emerging from these so called
thermokast lakes is up to five times higher than had previously been supposed.
Meanwhile less snow and sea ice are
leading to more of the sun's heat being absorbed by the land and the polar
oceans which in turn may speed up global climate change.
These are among the 'feedbacks' which
some experts fear could trigger even faster or more abrupt climatic changes
with even wider-ranging impacts on people, economies and wildlife.
Adaptation
Some communities are already adapting to
climate change. For example hunters in parts of Greenland are abandoning
traditional dog sleds in favour of skiffs as a result of less predictable sea
ice.
A key railway line in China, built on
permafrost, has been designed with special cooling technology to reduce the
risks of subsidence.
However the report acknowledges that many
indigenous peoples lack the financial resources and technology needed to
adapt. While, many parts of the world currently remain ill prepared for the
likely pace of climatic change.
Achim Steiner, UN Under-Secretary General
and UNEP Executive Director, said today: "This report is about ice and
snow and may to some people seem to address issues from remote and far away
places. But the report underlines that fate of the world's snowy and icy
places in a climatically challenged world should be cause for concern in every
ministry, boardroom and living room across the world. Indeed the findings are
as relevant to people living in the Tropics and temperate climes- and in
cities from Berlin to Brasilia and Beijing to Boston- as they are for the
people living in Arctic or in ice-capped mountain regions".
"The report comes in 2007, a year in
which climate change came in from the cold in terms of science, likely impacts
and costs. Indeed the Intergovernmental Panel on Climate Change has concluded
that the bill may be less than 0.1 per cent of global GDP a year. So
overcoming the climate change challenge is the bargain of the century,"
he added.
"The missing link is universal
political action. Today's report should empower the public to take their
leaders to task?should encourage them to ask how much hotter it has to get
before we act on a fair and forward-looking emissions reduction deal in Bali
this December," said Mr Steiner, who was speaking at the launch in
Tromso.
Helen Bjoernoey, the Minister of the
Environment for Norway, said: " This report gives us an overall picture
of the changes in snow and ice cover and the consequences for human beings and
nature, not only in the polar and mountainous areas, but all over the world.
To me it is particularly alarming to realize that climate change can be a
reinforcing process-global warming results in further global warming".
"As documented in the report,
melting of ice and snow will in itself have severe consequences on nature and
society. But it will also reduce the reflection of sun beams from the surface
of the Earth and in this way contribute to further global warming. Recent
scientific findings indicate that these changes may occur at a faster rate
than reflected in the IPCC 4th Assessment Report. So, there is reason for deep
concern," she said.
"The challenge of global climate
change can only be met through global political action. Norway has adopted as
an aim to limit the global temperature increase to a maximum of 2 degrees
Celsius. And we will work for having this limit adopted as a framework for
negotiations on future commitments under the UNFCCC. Norway is prepared to
take its share in this global effort. We will work actively towards a positive
result at this year's Bali meeting, which can pave the ground for adoption of
an agreement on global emission reductions at the latest in 2009," said
Ms Bjoernoey.
The Global Outlook for Ice and Snow,
involving UNEP and a network of some 70 of the world's best experts, has been
compiled in part to support the International Polar Year (IPY) running from
2007 to 2008.
The peer reviewed report builds on and in
some areas extends the work of the Intergovernmental Panel on Climate Change
(IPCC) whose fourth assessment reports were issued between February and May
this year.
The report also flags up areas in need of
further scientific clarity which the IPY, a major international science
initiative of the World Meteorological Organisation and the International
Council for Science of which UNEP is a partner, aims to resolve.
These include the likely fate of the
Antarctica and Greenland ice sheets where 98 to 99 per cent of the world's
freshwater ice on the Earth's surface is held.
A total meltdown of the Greenland ice
sheet would trigger an estimated seven metre rise in sea levels. Even just a
20 per cent melting of Greenland and a five per cent melting of Antarctica
would result in a four to five metre sea level rise.
This is a possibility over the coming
centuries if greenhouse gases are not reduced in the 21st century and this
might happen sooner if warming air and warming seawater continue to
destabilize parts of the ice sheets.
The melting of these sheets in
conjunction with those on mountain glaciers and ice caps, along with the
thermal expansion of the oceans, have so far led to a sea level rise of just
under 20 cm between 1870 and 2001?with sea levels rising by just over three
millimetres annually between the early 1990s and 2006.
Resolving just how much of the ice may
melt has direct consequences for people living in low lying areas and islands.
Based on today's population a one metre
sea level rise would, without adaptation measures, expose some 145 million
people to flooding with Asia most affected.
Areas of concern include many small
islands and populations living in the mega deltas of the Ganges-Brahmaputra,
the Mekong and the Nile in Africa. Low lying Bangladesh is singled out as a
country of particular concern.
The overall economic costs to
communities, livelihoods, industry and infrastructure could be nearly $950
billion under a one metre sea level rise scenario.
Christian Lambrechts of UNEP's Division
of Early Warning and Assessment said the new report was designed to support
the IPY in other ways.
"We hope that this Global Outlook
will demonstrate that the planet's ice and snow is intimately connected to all
life on Earth and not just those living or working in polar and mountain
regions," he added.
Joan Eamer of UNEP Grid-Arendal in
southern Norway said: "The Global Outlook is unique in the sense that it
brings together all the different forms of ice and snow that occur in the
world?collectively known as the cryosphere- and links them to the climate, to
nature and to people both now and in the future".
Pal Prestud of CICERO?the Centre for
International Climate and Environmental Research in Oslo and Chairman of the
Steering Committee for the new report, added: "One issue that rings
loudly throughout the report is the need for greater certainty with regards to
that fate of ice sheets. There are signs that these are breaking up, not just
slowly melting and to date we do not fully understand the processes behind
this".
"We can state with confidence that
sea level rise is increasing, but we lack the ability to predict how much the
ice sheets will in the end contribute to this over the next 10 years let alone
the next 50 years?all we can say is that their potential to dramatically
increase sea levels is enormous and far above the current UN Intergovernmental
Panel on Climate Change predictions," he added.
Snow
Seasonal snow cover is the main source of
runoff in the dry season in many mountain regions?globally over a billion
people depend on it for their water supplies for domestic, agricultural and
industrial uses including in some cases hydro-electric power generation.
Snow is also economically important for
winter sports, agriculture and animal husbandry such as reindeer herding and
survival of caribou. Snow that has melted and refrozen into ice can become too
hard for these animals to graze for their key food source?lichens.
"There have been catastrophic
declines in the Peary caribou on Arctic islands of North America and they are
now considered endangered. The formation of ice layers, following rain during
the winter..?has been identified as the chief cause of the declines,"
says the report.
Satellite monitoring shows that, since
the late 1960s, snow cover in the Northern Hemisphere has been decreasing by
1.3 per cent per decade.
The Western United States, particularly
in the spring in the Pacific North West, is among the regions seeing the
biggest decrease.
Here the 'depth' or quantity of water
from snow melt has fallen by between 50 per cent and 75 per cent over recent
decades.
Melting of snow in the Rocky Mountains of
British Columbia form the headwaters of the Columbia River. It supplies water
for larges areas of western Canada and north-west United States including for
important irrigation and hydroelectric schemes.
The Global Outlook for Ice and Snow says
that unchecked climate change will aggravate the changes. For example a 2
degree C temperature rise in the Cascade Range of mountains of the Pacific
North West of the United States could "reduce temperate snow cover by
over 20 per cent".
Similar impacts are likely in the Andes,
the Alps and the Pyrenees which in turn will decrease summer water run off.
For every one degree C rise in temperature, the snow line is predicted to move
up the mountains?by 120 metres in Chile for example and by 150 metres in the
Alps.
The report notes that the declines in
snow will not be uniform with some climate models indicating reductions of
snow of between 60 per cent and 80 per cent in middle latitudes like Europe by
the end of the century?but increases in Siberia and the Canadian Arctic by the
same time as a result of increased precipitation.
Changes in patterns of snow are likely to
impact on tourism and recreation including skiing and snowmobiling.
"Other less widespread winter sports
such as dog mushing, sledding and snowshoeing can be important to local
economies and are impacted when snow arrives anomalously late, too little or
not at all," says the report.
Frozen Ground or Permafrost and the
Increase in Methane Bubbling Lakes
Permafrost or frozen ground is important
for the stability of buildings and infrastructure. Subsidence is one
manifestation of thawing permafrost.
These soils also contain large quantities
of ancient greenhouse gases which could be released into the atmosphere as a
result of widespread thawing.
"The upper part of permafrost in
boreal and arctic ecosystems is estimated to contain around 750 to 950
gigatonnes of organic carbon," says the report. Currently there are
around 750 gigatonnes of organic carbon in the atmosphere.
Some models predict that permafrost
could, by the end of the century, be thawing in "practically all areas
south of the Brooks Range in Alaska and in most of a sub artic Canada. In
Russia the most severe permafrost degradation is projected for northwest
Siberia and the European north. Almost all permafrost along the southern
coasts of Greenland will be thawing by the end of the 21st century".
The area of permafrost in China is
expected to decline by 30 per cent to 50 per cent during this century.
Some countries are already adapting
infrastructure to cope with projected permafrost thawing. The design of the
Qinghai-Tibet railway already factors in the likely impact of a 2.6 degree C
temperature rise by incorporating cooling techniques.
"The impacts of climate changes on
stability will also need to be considered in the design of the proposed
China-Russia oil pipeline," says the report.
Thermokast Lakes
The report also flags up the curious case
of lakes forming in places like Siberia as a result of the thawing of ice rich
permafrost. Bubbles of methane, estimated to be up to 43,000 years-old, are
being released to the atmosphere.
In Siberia, the amounts of methane being
released maybe five times higher than was previously supposed.
"If significant permafrost warming
and thawing occurs as projected, tens of thousands of teragrams of methane
could be emitted from lakes?an amount that greatly exceeds the 4,850 teragrams
of methane currently in the atmosphere," says the report.
Sea Ice
Sea ice is important in relation to ocean
circulations such as the Gulf Stream and is also important for the food chain
and also for wildlife such as polar bears and walruses as well as fisheries.
The livelihoods and cultures of coastal
Arctic indigenous people are inextricably linked with sea ice.
Nearly four million people live in the
Arctic including indigenous peoples. Impacts are already being felt. Hunters
in Qeqertarsuaq, Western Greenland, are replacing dog teams with motor boats
because of a lack of solid ice.
Overall the extent of sea ice in the
north has decreased by 2.5 per cent per decade in March and close to nine per
cent in September over the past quarter century. At just over 10.5 per cent,
the biggest decline has been in the Greenland Sea.
In Antarctica the trend is less clear cut
with a weak 'non-significant' overall increase in its extent, for example, in
the Ross Sea of 4.8 per cent per decade but a decrease in, for example, the
Bellingshausen Sea of 5.3 per cent per decade.
Sea ice extent in both polar regions is
expected to decline by a quarter by 2100 with the Arctic largely ice-free in
the summer by the same date. But the report also points to possible abrupt
changes or 'tipping points' that could bring an ice-free Arctic in the summer
months forward by 60 years.
The Northern Sea Route along the Siberian
coast is currently navigable for 30 days but this could increase to 120 days
during the century?a new economic opportunity for the region-but one, along
with greater access to oil and gas fields and fisheries, that will require
careful environmental management.
Glaciers
Many glaciers are already receding in
response to climate change. The report says that a three degree C rise in
summer air temperatures could see the Alps lose about 80 per cent of their
glacier cover.
Heavily glaciated areas like Argentina
and Chile's Patagonia region and the St Elias Mountains in Alaska could see
the collapse of these ice bodies.
The formation of lakes as a result of
melting glacier and the risks of glacial lake outburst floods or GLOFs is also
highlighted. Such lakes have potential to release up to 100 million cubic
metres of water at speeds of up to 10,000 metres a second down vulnerable
valleys.
Mountain regions at risk include the
Himalayas, Tien Shan and the Pamirs of Tajikistan but also the Andes and the
European Alps.
In July 1998 a GLOF in the Shahimardan
valley of Kyrgyzstan and Uzbekistan killed over 100 people. Another in August
2002 in the Shakhdara valley of the Tajik Pamir mountains claimed 23 lives.
Meanwhile in Asia the lives of some 2.4
billion people?40 per cent of the current global population?are influenced by
the summer meltwaters of glaciers in the Himalayas-Hindu Kush, Kunlun Shan,
Pamir and Tien Shanan mountain regions.
These glaciers could shrink by between
just over 40 per and up to around 80 per cent by 2100 under current climate
models with some mountain ranges completely devoid of glacial coverage.
Rivers at risk include the Syr Darya, Amu
Darya, Indus, Ganges, Brahmaputra, Yangtze and Huang He or Yellow river where
some 1.3 billion people could be at increased risk of water shortages and many
more at risk of losing irrigation water for crops as well as disruptions to
industry and power generation.
African glaciers have lost over 80 per
cent of their area indicating major changes in climate and other phenomena
such as rainfall.
River and Lake Ice
Freshwater ice is an important component
of many river and lakes in the Northern Hemisphere including North America's
Red River; Finland's Lake Kallavesi and Tornionjoki river and the Angara river
in south east Siberia.
Long term records indicate that rising
air temperatures in the autumn and spring have produced a 10 to 15 day delay
in 'freeze up' and a similar advance in break up.
Models indicate that continued climate
change might change the timing and magnitude of spring melting affecting
spring 'ice jam' flooding in communities. Climate change might actually reduce
these dramatic events in the far north?but this could lead to the extensive
wetlands on Arctic river deltas drying out and turning to shrubland.
There is also concern over the impacts on
fish and other biodiversity and links between transport and indigenous
peoples. Currently many remote communities use frozen lakes and rivers as
routes to traditional hunting, fishing and trapping areas or for accessing
larger human settlements.
Notes to Editors
The Global Outlook for Ice and Snow was
launched today at World Environment Day 2007 held in Tromso, Norway. It, along
with downloadable pictures, is available at http://www.unep.org/geo/geo_ice
The book is available for purchase at
www.earthprint.com priced USD 40
World Environment Day, commemorated each
year on 5 June, is one of the principal vehicles through which the United
Nations stimulates worldwide awareness of the environment and enhances
political attention and action. The World Environment Day slogan selected for
2007 is Melting Ice ? a Hot Topic? In support of International Polar Year, the
WED theme selected for 2007 focuses on the effects that climate change is
having on polar ecosystems and communities, and the ensuing consequences
around the world.
The main celebrations will be held in
Tromsψ, Norway, a city with a living polar history which also hosts a centre
for polar research. The highlights of the celebrations include an ecumenical
service led by Archbishop Desmond Tutu in the Arctic Cathedral, the awards
ceremony for the winners of UNEP's 16th International Children's Painting
Competition on the Environment, with prizes presented by Crown Prince Haakon
of Norway, a scientific conference on the theme of climate change at Tromsψ
University, the Sophie Prize awards ceremony, and an art exhibition, as part
of UNEP's art and environment initiative.
For more information see www.unep.org/wed/2007
and www.wed.npolar.no
A full programme of events can be found
at www.regjeringen.no
For More Information Please Contact Nick
Nuttall, UNEP Spokesperson, on Tel: +254 20 7623084, Mobile: +254 733 632755,
Alternative Mobile: +254 727 531 253 E-mail: nick.nuttall@unep.org
