http://news.bbc.co.uk/2/hi/science/nature/3077422.stm
Last Updated: Thursday,
4 September, 2003, 12:31 GMT 13:31 UK
Kazakhstan's
glaciers 'melting fast'
By Alex Kirby
BBC News Online environment correspondent
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#1:
"I think we have to say that climate is affecting the glaciers"
Dr Stephan Harrison, University of Oxford
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#2:
"The Tien Shan range runs across China, Kazakhstan and Kyrgyzstan"
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#3:
"The glaciers keep the plains alive"
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#4:
"Many Kazakhs face a drier future"
The political stability of a key central Asian state could be
imperilled by climate change, researchers say.
They say glaciers are melting so fast in parts of Kazakhstan
that the livelihoods of millions of people will be affected.
They found the area's
glaciers were losing almost two cubic
kilometres of ice annually during the later 20th Century.
With regional temperatures
rising, they believe climate change
is responsible.
The scientists, led
by Dr Stephan Harrison of the University
of Oxford, reported their findings at the annual conference
in London of the UK's Royal Geographical Society and Institute
of British Geographers.
They concentrated
on the Zailiiskiy Alatau range of the northern
Tien Shan mountains, which stretch through Kazakhstan and its
neighbour Kyrgyzstan, and into China (the name means "the
celestial mountains").
The mountains, which
run for 2,000 km (1,250 miles) along the
north-west edge of the Tibetan plateau, form an important
climatic barrier between the Siberian and central Asian air
masses.
Long observation
period
There are 416 glaciers
in the region, covering 510 square km
(197 square miles).
Dr Harrison and his
colleagues, from the University of Newcastle,
UK, von Humboldt University, Germany, and the Kazakh Academy of
Sciences, say they have been losing nearly two cubic km of ice
a year between 1955 and 2000.
Between 1974 and 1990,
the glaciers lost 1.28% of their
volume each year.
The Tuyuksu glacier,
30 km (18 miles) south of Kazakhstan's
largest city, Almaty, has been monitored by the country's
scientists since 1902, with less detailed observations dating
back to the 1870s.
Since 1923 it has receded
by nearly a kilometre, losing about
51 million cubic metres of ice.
The team says these
changes have serious implications
for river runoff, and therefore for Almaty's water supply.
Many of the rivers
which supply the irrigation schemes essential
to agriculture are fed by glaciers and permafrost in the upper
ranges of the Tien Shan, so the livelihoods of millions of people
will be affected.
The authors say not
only Kazakh agriculture and development
will be jeopardised but the political stability of a swathe
of central Asia, as many of the rivers and glaciers cross state
frontiers.
Warming up
Kazakhstan uses about
90% of its water for irrigation, with
an efficiency of only 40-60%, and it is adding 9,000 hectares
(22,000 acres) to the irrigated area every year.
The scientists say
the glaciers' "consistent pattern of retreat
over the latter part of the 20th Century... is associated with
a small but pervasive rise in mean annual temperatures".
Dr Harrison said: "The
effects of global warming on glaciers
are not just of interest to scientists, as glacial retreat
has profound political, economic and social repercussions."
He told BBC News Online:
"I think we can be certain the reason
why the Tien Shan glaciers are melting is climate change.
Uncontaminated
evidence
"We have the climate
records themselves, which go back to early
last century. Sceptics often argue that records of this sort
are contaminated by the proximity of urban centres.
"But these records
are from glaciers 3,000 m (9,800 feet) up,
nowhere near any towns or cities.
"They're confirmed
by the evidence from tree rings, which
preserve a record of climate conditions as they grow, and
by the meteorological records.
"Taking all three
together, I think we have to say that
climate is affecting the glaciers."
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