Download Climate change effects on Mount Kenya`s Glaciers

ENVIRONMENTAL PROBLEMS and DEVELOPMENT
Climate change effects on Mount Kenya’s Glaciers
MIHAI VODĂ, VICTOR SOROCOVSCHI, RAMONA RAŢIU, RADU NEGRU
Faculty of Geography
Dimitrie Cantemir University
Targu Mures, Bodoni Sandor 3-5, 540545
ROMANIA
Abstract: - Mount Kenya is the second highest mountain in Africa and one of the few equatorial mountains with an ice
cap, attracting a lot of tourists each year. Rising air temperature represents the primary driver of glacier future
disappearance in the high areas of the mountain. The present warming and associated glacier retreat are unprecedented at
high elevations in the Mount Kenya. The continuing retreat of glaciers, many having persisted for thousands of years,
signals a recent and abrupt change in the Earth's climate system.
Key-Words: - climate change, glaciers, tourism, mountains, vulnerability.
1 Introduction
2 Climate change
Climatic change has sensitive indicators
represented by the low latitudes high mountains glaciers,
near the Equator. Ice is still found on Mount Kenya, where
Dr. Mihai Voda conducted research expeditions and
observed the glaciers retreat from 2000 till 2007 [7]. The
last seven years annual temperatures where among the
highest ever measured, contributing to the ice recession in
the glaciated high areas of Mount Kenya.
Mount Kenya is the second highest mountain in
Africa (5199 m or 17,330 ft) and one of the few
equatorial mountains with an ice cap, attracting a lot of
mountaineers, hikers and tourists. The mountain is
located in the Mount Kenya National Park, which is a
designated protected area around the mountain above
3200 m altitude.
The Kenya Wildlife Service manages the park.
The national park covers an area of 700 square
kilometers and was established in 1949. Deforestation
and pollution have already made a big gap on the top
glaciers of Point Lenana, Bation and Nelion. Mount
Kenya lost 92 % of its ice cap in the last century. This
mountain is very important in the hydrological system
of Kenya, being the origin for many rivers that are
major sources of water and hydrological power.
One Mount Kenya glacier is already completely
lost. But the loss of ice could menace many species, like
leopards and monkeys, adapted to the Mount Kenyas'
"microclimates," ranging from forest to heather and
icepack.
The results of recent climate change impact studies
confirm the assumption that the negative impacts of
climate change do not occur equally in spatial respect.
This is due to the fact that different types of landscapes
differ in their vulnerability to climate change in terms of
the main climate parameters “temperature” and
“precipitation”.
A general rise in mean temperatures leads to a
moderate increase in natural areas with vegetation
because of a higher ventilation and cooling due to
evaporation. In contrast, the temperature rise leads to a
disproportionate rise in the cores of naked mountains.
Regions are thus affected by climate change to a
large extent depends on the vulnerability of the types of
landscape that exist within the region.
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2.1 Glaciers vulnerability
Most studies from the climate change community
can be referred to as an end point vulnerability
assessment when examining climate vulnerability
research.
Future vulnerability is the residual of climate
change impacts minus adaptation efforts. This requires
information about the dynamism of vulnerability and
adaptation effects over time, which is still a difficult
issue to tackle especially over long time scales.
A different concept is the vulnerability ‘starting
point approach’, which focuses on the current system
and its vulnerability [1].
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ENVIRONMENTAL PROBLEMS and DEVELOPMENT
12oC in July-August. There are two rainy seasons on the
mountain from April-June and October-December.
Mount Kenya is an important water catchment
area and many rivers such as the Naro Moru emerge
from the melting glaciers.
Temperature distribution in a glacier depends on
air temperature, accumulation, solar radiation, clouds,
surface albedo, wind, meltwater runoff, percolation
and refreezing of meltwater, ice flow and other
parameters. On any given glacier, many of these
parameters are known with uncertainties.
The latter approach assumes the future is
inherently uncertain and hence it is impossible to
generate credible information about how vulnerable
areas will develop over time.
Moreover, the climate change community has also
developed its own understanding of vulnerability, which
in some cases is defined as the ability of a system to
resist extreme events and changes in climate.
2.2 Retreating glaciers
In East Africa glaciers began to recede only in the
1880's, concomitant with a climatic dislocation also
manifest in the sudden drop of water level in the great
lakes.
The cause for the onset of glacier retreat is seen in
increased net shortwave radiation accompanying
decreased cloudiness and precipitation associated with a
drastic change of circulation over the equatorial Indian
Ocean [3].
On Mount Kenya, the largest glaciers are extended
to the Southwest of the mountain, because of the strong
diurnal circulation and because of the differential
insulation resulting from the location of the mountain in
the northern hemisphere.
The Barlow Glacier on the Northwest face of Point
Piggot, the Kolbe Glacier, located Northeast of Point
Lenana and the Melhuish Glacier to the Southwest of
Point Melhuish are some of the glaciers that have melted.
Of the 18 ice entities at the end of the 19th century, 8
disappeared altogether, and all suffered substantial loss.
The Mount Kenya Lewis Glacier fluctuated from
an area of 0.60 square km in 1890 to 0.26 square km in
1982. In the same period, the elevation of the terminus
rose from 4,465 m to about 4,600 m. Maximum ice flow
velocity was estimated to about 15 m per year at the
early part of the 20th century, while in 1982 the observe
velocity was only about 3 meters per year [6].
"At this rate they will be gone in 10 years," said
Levente Szasz, member of the ten-day Dimitrie
Cantemir University expedition. Local tourism would
be affected too: thousands of tourists have visited the
Mount Kenya glaciers in the past years.
The Krapf Glacier, Gregory Glacier, Lewis Glacier,
Darwin Glacier (drastic decay from 1978 to 2006),
Tyndall Glacier (stretching from 1949 to 2004), Cesar
Glacier, Joseph Glacier and Northey Glacier have been
presented in the Hastenrath photo documentation of the
retreating glaciers.
The mountain annual temperature range is about
2oC, with the lowest values in March-April and highest
in July-August. Kenya has a climate with average
annual temperatures of about 26oC. Diurnal
temperatures range very large on Mount Kenya,
amounting to about 20oC in January-February and about
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2.3 Climate change and tourism
Tourism has attracted attention as both an
important contributor to climate change through its
greenhouse gas emissions, and as an industry that is
potentially at high risk given the predicted changes in the
global climate. The First Conference on Climate Change
and Tourism convened by the World Tourism Organisation
signals rising interest in the link between the two global
phenomena, although the main research focus at this
stage seems to be on the threat of a changing climate on
tourist destinations.
Tourism's role as contributor to climate change
has largely been neglected, with only few studies having
investigated energy use and greenhouse gas emissions
associated with tourist activities [2].
The main actors in tourism are the tourists
themselves, who make their travel decisions and exert
considerable market power.
Little is known, however, about whether tourists
are aware of how their travel impacts on global climate,
and conversely what impact a changing climate may
have on tourist destinations.
Moreover, there has been no research on the
willingness of tourists to mitigate such effects.
Almost all tourism experts believed that
climate change is an issue for tourism. Generally, tourism
experts focused on the impact of a changing climate on
tourism [2].
At the moment the mountain attracts several
thousand climbers annually, both local and
international. It is this popularity that has contributed to
the deterioration of the environment and the litter
accumulation. The solution might be ecotourism
activities implementation.
Kenyan nature reserves have obtained actual
effects in promoting sustainable development of
ecotourism among local communities nearby Mount
Kenya. Increasing community interest in a continuously
participation is the key for ecotourism planning in
Mount Kenya National Park.
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ENVIRONMENTAL PROBLEMS and DEVELOPMENT
seasonal variations affected Mount Kenya Glaciers.
The penetration depth of seasonal temperature
variations, is determined by the period of variations and
the properties of the glacier: density, heat capacity and
thermal conductivity [8].
Therefore, daily temperature variations are 20
times smaller at approximately 0.6m depth, and the
yearly thermal wave penetrates down to 15-20 m,
while thermal disturbance can reach 150 m depth
within approximately 160 years [12].
3 The causes
Global warming is seen as the main culprit.
Others point to a natural decrease in humidity that
began in the late 1800s. Human activity is having an
impact on the Mount Kenya’s glaciers.
Throughout the tropics, all the glaciers are
receding. Whether the cause is decreased humidity or
increased temperature, the results are the same.
In the Andes precipitation has increased in the
last hundred years, but the glaciers are still retreating.
It seems that rising air temperature, not reduced
precipitation, represents the primary driver of glacier
retreat in the tropics and subtropics [10].
The large-scale dynamics of the tropical
climate system have changed. Horizontal temperature
variations are small above a relatively shallow
atmospheric layer near the Earth's surface.
This condition results from the lack of a strong
Coriolis effect to balance pressure differences resulting
from temperature variations, and thus the tropical
atmospheric mass is redistributed so as to nearly
eliminate horizontal temperature gradients [9].
Of the meteorological variables controlling
glacier mass balance (temperature, precipitation,
cloudiness, humidity, etc.), only temperature exhibits
large-scale spatial homogeneity, suggesting that it is the
primary variable driving the retreat of most tropical ice
fields.
A decrease in annual precipitation of the order
of 150 mm and associated cloudiness and albedo
variations during the last quarter of the 19th century,
followed by a temperature rise of a few degrees
centigrade during the first half on the 20th century, are
identified as the major climatic forcing of the observed
glacier response [6].
Glaciers observations are essential in
monitoring climatic change in the tropics. The photo
documentation made during the Dimitrie Cantemir
expedition in 2000 made possible the comparison with
the glaciers photographs taken from the same positions
during the Dimitrie Cantemir University 2007
expedition.
The results are obvious: Mount Kenya Glaciers
are melting faster than ever. Gregory and Krapf
Glaciers almost disappeared and Lewis Glacier, the
biggest of them all, retreated to higher altitudes with a
lot of lost ice from the southern and eastern side.
The tropical Lewis Glacier (Fig.1) retreated by
more than 800 m between 1893 and 2004 and lost
almost 16 m water equivalent of its thickness between
1979 and 1996 [11].
Mount Kenya guides said, in December 2007,
that they have never seen such an intensive melting
process as in the last seven years. It seems that the
annual rise of the global air temperature and the
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Fig.1 Shrinking Lewis Glacier, Mount Kenya [11]
Because Mount Kenya glaciers experience
surface melting, their temperature is close to the
melting point, and a small fall or rise in air
temperature, as during the last seven years, could have
a significant impact on the heat and mass balance at
the surface and consequently in the whole glacier
within a relatively short period of time.
4 Conclusion
The recent, rapid, and accelerating retreat of
glaciers on a near-global scale suggests that the
current increase in the Earth's globally averaged
temperature may now have prematurely interrupted
the natural progression of cooling in the late
Holocene [4].
These observations suggest that within a
century human activities may have nudged globalscale climate conditions closer to those that prevailed
before 5,000 years ago, during the early Holocene. If
this is the case, then Earth's currently retreating glaciers
may signal that the climate system has exceeded a
critical threshold and that most low-latitude, highaltitude glaciers are likely to disappear in the near
future [10].
A large and unusual warming is underway at
high elevations in the tropics. Although the factors
driving the current enrichment (warming) may be
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[10] Thompson, L.G., E. Mosley-Thompson, H.
Brecher, M.E. Davis, B. Leon, D. Les, T.A. Mashiotta,
P.-N. Lin, and K. Mountain, Evidence of abrupt tropical
climate change: past and present. Proceedings of the
National Academy of Sciences, 103(28), 2006, 1053610543.
[11] UNEP/GRID-Arendal. Shrinking Lewis Glacier,
Mount Kenya [Internet]. UNEP/GRID-Arendal Maps
and Graphics Library; June 2007 [cited 2008 Oct 24].
Available
from:
http://maps.grida.no/go/graphic/shrinking-lewis-glaciermount-kenya.
[12] Zagorodnov, V., Nagornov, O., Thompson, L.G.,
E., Influence of air temperature on a glacier's active-layer
temperature. Annals of Glaciology, 43, 2006, 285-289.
debated, the tropical ice core confirms that it is
unusual from a 2,000-yr perspective.
Whether it is interpreted as a function of
temperature,
precipitation,
or
atmospheric
circulation, the important message clearly preserved in
these high-elevation ice fields is that the large-scale
dynamics of the tropical climate system have
changed.
During the rainy seasons, the peak area of
Point Lenana is often covered in snow, with depth on
the glaciers of one meter or more. As a result of
insulation conditions, the southern slopes of the
mountain become snow free during the DecemberMarch season, whereas in July-October the north
face becomes bare.
Above 4,500 m altitude most of the annual
precipitation falls in solid form. The maximum
rainfall altitudinal belt lies around 2,700 – 3,100 m
with amount decreasing towards the peak area. The
wettest sector is on the outcast slopes Mount Kenya,
with up to 2,500 mm per year, whereas the driest part
to the north may receive less than 1,000 m per year.
Yet, it seems that rising air temperature represents the
primary driver of glacier retreat in high areas of Mount
Kenya.
References:
[1] Adger, W. N., S. Huq, Brown, K., Conway, D. and
Hulme, M., Adaptation to climate change in the
developing world. Progress in Development Studies 3,
2004, 179-195.
[2] Becken S., How Tourists and Tourism Experts Perceive
Climate Change and Carbon-offsetting Schemes, Journal
of Sustainable Tourism, Vol.12, No.4, 2004, pp. 332-342.
[3] Hastenrath, Stefan. Recession of equatorial glaciers:
A photo documentation. Sundog Publishing, Madison,
WI, 2008.
[4] Hansen, J. E., Ruedy, R., Sato, M., Imhoff, M.,
Lawrence, W., Easterling, D., Peterson, T. & Karl, T.,
Geophys. Res D Atmos. 106, 2001, 23947-23963.
[5] Jones, P. D. & Moberg, A., Hemispheric and largescale surface air temperature variations: An extensive
revision and an update to 2001. J. Climate 16, 2003,
206-223.
[6] Mountain Club of Kenya, Guide to Mount Kenya and
Kilimanjaro, Nairobi, 4rd. Edition, 1998.
[7] Negru, R., Voda, M., Trasaturi geomorfologice si
glaciare în Mount Kenya, Terra, Vol.1-2, 2002, pp.126-129.
[8] Paterson, W.S.B., The physics of glaciers. Third
edition. Oxford, Elsevier, 1994.
[9] Sobel, A. H., Nilsson, J. & Polvani, L. M., The weak
temperature gradient approximation and balanced
tropical moisture waves, J.Atmos. Sci. 58, 2001, 36503665.
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