Glaciers are melting rapidly due to climate change, threatening water supplies. The Himalayas contain the largest store of glacial ice outside the poles and supply water to over 2 billion people. As glaciers melt, initial floods will be followed by water shortages. Regions heavily dependent on glacial meltwater for agriculture, like parts of South America, are particularly at risk. Wildlife is also threatened by habitat loss as glaciers recede. Water harvesting techniques are helping high-altitude communities adapt to less predictable water availability.
2. TOPIC: RAPIDLY MELTING GLACIERS
Submitted by : HVK 1555
STUDY CIRCLE: ECOSYSTEMS AND
LIVESTOCK
3. • Mass of moving glacial ice
created by the accumulation
of snow.
• glaciers always moving
forward at terminus.
• ice & water move forward.
• Glaciers are ancient rivers of
compressed snow that creep
through the landscape,
shaping the planet’s surface
• They are the Earth’s largest
freshwater reservoir,
collectively covering an area
the size of South America
WHAT IS A GLACIER?
A large glacial lake formed due to melting
of the Imja Tso glacier in the Himalayas
4. • Glaciers form only on land and are distinct from the much
thinner sea ice and lake ice that form on the surface of bodies of
water.
• On Earth,99% of glacial ice is contained within vast ice sheets in
the polar regions, but glaciers may be found in mountain
ranges on every continent.
• Glaciers cover about 10 percent of Earth's land surface.
5. CAUSES OF CLIMATE CHANGE
• The greenhouse effect causes the atmosphere to retain heat
• The ocean releases CO2 into the atmosphere and absorbs
atmospheric CO2 at a slower rate.
• Main greenhouse gases:
• carbon dioxide (CO2), methane (CH4), nitrous oxide (N2O)
• Cutting down forests (deforestation) :changes to land cover
(replacement of darker forests with paler croplands and
grasslands)
• Increasing livestock farming. Cows and sheep produce large
amounts of methane when they digest their food.
7. MELTING GLACIERS
• Projected climate change over the next century will further affect
the rate at which glaciers melt.
• Average global temperatures are expected to rise 1.4-5.8ºC by
the end of the 21st century
• Although only a small fraction of the planet’s permanent ice is
stored outside of Greenland and Antarctica, these glaciers are
extremely important because they respond rapidly to climate
change and their loss directly affects human populations and
ecosystems..
8. • Continued, widespread melting of glaciers during the coming
century will lead to floods, water shortages for millions of
people, and sea level rise threatening and destroying coastal
communities and habitats
9.
10. REGIONS AT RISK
• Ecuador, Peru and Bolivia – where shrinking glaciers supply
water year-round, and are often the sole source of water for
major cities during dry seasons.
• The Himalayas – where the danger of catastrophic flooding is
severe, and glacier-fed rivers supply water to one third of the
world’s population.
• Small island nations such as Tuvalu and some of the Solomon
Islands – where sea level rise is submerging low-lying land and
saltwater is flooding vital groundwater reserves.
11. Earth with a sea level rise of six meters. A new study finds that human activities are
responsible for 87 percent of the sea level rise since 1970 that’s been caused by swelling
volume of the upper ocean
12. NATURE AT RISK
• Royal Bengal tiger – endangered tigers that will lose a large
portion of their worldwide habitat as the Sundarbans succumb to
sea level rise.
• Kittlitz’s murrelet –rare birds specialized to hunt in cloudy
glacier water and nest on top of ice.
• Coral reefs – unique organisms that can be starved of energy
from the sun when sea levels rise.
13. Bengal tigers face a loss of habitat as glaciers retreat.
Their natural habitat in the mangrove forests of the
Sundarbans region of Bangladesh and India is being
drowned as sea level rises and inundates this area.
14.
15. HABITAT LOSS
Animals that dwell on or near glaciers may be pushed towards
extinction by the disappearance of their icy habitats like polar bear
penguins ,seal ,snow leopard etc.
16. • Kittlitz’s murrelett, is a small, diving seabird that forages for food
almost exclusively in areas where glacial meltwater enters the
ocean.
• These birds are already in serious trouble; their global population is
thought to have decreased from several hundred thousand in 1972
to less than 20,000 in the early 1990s.
The Kittlitz’s murrelet is found only in Alaska and portions of
the Russian Far East.
17. Coral reef:
• Corals need light in order to survive, but as sea level rises the deeper water can
block the sun’s nourishing rays.
• This has consequences not only for the corals and marine life, but for the human
communities that rely on these reefs for subsistence.
18.
19. CONTAMINANTS
• Although Persistent Organic Pollutants (POPs) such as
PCB(polychlorinated biphenyls) and
DDT(Dichlorodiphenyltrichloroethane ) are widely banned today,
they were used extensively in the middle of the last century.
• These long-lived pollutants are transported in the air from their
source to cooler areas where they condense and are deposited
in glacial ice.
• Until recently, these compounds had remained trapped in the
ice, but rapid melting has begun to release them back into the
environment
• For example, in one Canadian lake, glacial meltwater is the
source of 50-97% of the various POPs entering the lake17
20.
21. THE HIMALAYAS
• The Himalayas contain the largest store of water outside the polar ice
caps, and feed seven great Asian rivers
• Himalayas is nicknamed “Water Tower of Asia”
• Largest body of glaciers outside of polar regions, occupy 17% of
mountain area
• Glaciers supply freshwater to 500 million people in Himalaya-Hindu-
Kush region and 250 million people in China
• 2 billion people in the river basins depend on the Himalayan glaciers
for their water supply
• There are 3,300 glaciers in the Nepalese Himalayas and 2,300 of
them contain glacial lakes. These lakes are quietly growing because
of rising temperatures, but nobody knows how many are close to
bursting, and there are no early warning systems for the villages
downstream.
22. Nearly all the great rivers of Asia
begin in the Tibetan Plateau
23. WATER SHORTAGE
• Although our planet appears to be a watery oasis when viewed
from space, most of this liquid is far too salty for humans, plants
or animals to consume.
• Only about 2.5% of the water on earth is freshwater, and less
than one-hundredth of one percent is drinkable and renewed
each year through precipitation
• Freshwater is already a limiting resource for much of the planet,
and in the next 30 years population growth is likely to far exceed
any potential increases in available water
24. • The Himalayan glaciers that feed seven of the great rivers of Asia
(the Ganga, Indus, Brahmaputra, Salween, Mekong, Yangtze and
Huang He) and ensure a year-round water supply to 2 billion
people are retreating at a startlingly fast rate. In the Ganga, the
loss of glacier meltwater would reduce July-September flows by
two thirds, causing water shortages for 500 million people and
37% of India’s irrigated land.
25. WATER HARVESTING
• To deal with water shortages
and an unpredictable water
supply, high altitude areas
have developed water
harvesting-methods by
storing water as ice.
• Few techniques are used
26. • 1.Snow water harvesting
• In the mountainous areas of Afghanistan and Iran some
communities pack snow in watertight pits, so that spring and
summer melt can provide the households with drinking water.
• The snow is commonly carried in bags by donkeys, emptied in
the pits where it is compacted and then covered with soil.
• . This particular water harvesting technique is good for domestic
use, but for securing water availability for agricultural production
a larger reservoir is needed
27. • 2.Glacial grafting
• For glacier grafting, villagers transport glacial ice to shaded, high altitude
valleys where it is packed between rocks or in caves .
• The packed ice serves as a seed that spurs the growth of new ice masses
that can grow up to 250 meters in length and contain around 200-400 kg of
ice (approx. 200-400 L of water)
28. • .3. Artificial Icings (Artificial Glaciers)
• This method was developed in Ladakh, Northern India by
Chewang Norphel, the “Iceman of Ladakh” and is being
constructed in more and more villages.
• By diverting meltwater through a network of pipes into artificial
lakes in the shaded side of mountain valleys, he says he has
created new glaciers.
• A dam or embankment is built to keep in the water, which
freezes at night and remains frozen in the absence of direct
sunlight. The water remains frozen until March, when the start of
summer melts the new glacier and releases the water into the
rivers below.
29.
30. • The 'ice stupa' are artificial glaciers built at lower altitudes using pipes,
gravity and cold temperatures
• It was the idea of Sonam Wangchuk, an engineer from Ladakh, in the
Jammu region of north India
• The region receives on average of just 50mm of rainfall each year, and
locals rely on water from glaciers
• To create a ice stupa, pipes connect to a stream of water from higher in the
mountains which flows down
• The pressure created by this difference in heights creates a fountain which
freezes in the winter months