FABLED ICE FIELD ’ SET TO VANISH ’
FABLED ICE FIELD ’ SET TO VANISH ’
2006-05-17 at 9:46:00 am #15470
Fabled ice field ‘set to vanish’
A fabled tropical ice field in Africa could disappear in two decades because of climate change, a study says.
The finding comes from the first survey in a decade of glaciers in the
Rwenzori Mountains, East Africa, often referred to as the “Mountains of
A British-Ugandan team says an increase in air
temperature over the last four decades has contributed to a substantial
reduction in glacial cover.
Details of the work appear in the journal Geophysical Research Letters.
Tropical glaciers are very sensitive indicators of tropical climate.
They indicate quite clearly that the climate is changing
Richard Taylor, UCL
The Rwenzori Mountains straddle the border between Democratic Republic of Congo and Uganda.
They are home to one of four remaining tropical ice fields outside the
Andes and are renowned for their spectacular and rare plant and animal
Their legendary status may stretch back to a reference
by the 2nd Century AD Greek geographer Ptolemy, who wrote of
snow-capped equatorial peaks that fed the Nile: “The Mountains of the
Moon whose snows feed the lakes, sources of the Nile”.
Some researchers think conceptual maps prepared by
Ptolemy are a good fit for the Rwenzori, which feeds Lake Albert, which
in turn feeds the White Nile.
An analysis of data from field surveys and images from
the LandSat satellites shows the combined area of the Rwenzori glaciers
has halved from around two sq km to just under one sq km since 1987.
Weather data collected from field stations shows that
increased air temperature is the main driver behind the loss of glacial
Trends point to an air temperature rise of roughly half a degree
Celsius per decade since the 1960s without any significant change in
Dr Richard Taylor of University College London and
colleagues extrapolated the data on glacial shrinkage since 1906 and
found that the glaciers would disappear within 20 years if trends
“The observed increases of about 0.5C per decade are much greater than
you would expect,” Dr Taylor told the BBC News website. “You would
expect, consistent with warming trends for the East African region,
about 0.1-0.2C per decade.”
Rainfall data for the region extends back 100 years, but
temperature records go back no further than the 1960s. Consequently,
the researchers were unable to say whether they are observing a
There were no field stations higher than 1,800m
(6,000ft) above sea level, which meant the scientists had to infer
temperature and rainfall data from information gathered at lower
altitudes. However, this was relatively straightforward and reliable,
Dr Taylor explained.
Loss of cover
The UCL scientist added: “Tropical glaciers are very sensitive
indicators of tropical climate. They indicate quite clearly that the
climate is changing.”
Local biodiversity is not expected to suffer in the
short term, but habitats for rare vegetation could be constrained in
the longer term.
The largest conglomerations of equatorial ice are in
the Andes in South America, representing over 90% of glacial cover in
Of the four outside the Andes, about two sq km of ice
remains on Irian Jaya, 0.4 sq km on Mount Kenya, three sq km on
Kilimanjaro and 0.96 sq km in the Rwenzori.
The disappearance of the glaciers would have a
negligible effect on Nile waters, to which the major contribution comes
from rainfall at lower altitudes.