Glaciers Recede in East Africa’s “Mountains of the Moon”

Speke Glacier in the Rwenzori Mountains with distinctive Afroalpine vegetation, Tree Senecio (Dendrosenecio adnivalis), in the foreground. (photo: Richard Taylor)
Speke Glacier in the Rwenzori Mountains with distinctive Afroalpine vegetation, Tree Senecio (Dendrosenecio adnivalis), in the foreground. (photo: Richard Taylor)

The Rwenzori Mountains of equatorial East Africa are widely known to be the legendary “Mountains of the Moon” described by Ptolemy in 150 A.D. as ‘the Mountains of Moon whose snows feed the lakes, sources of the Nile’. Indeed, snow and ice on these glaciated mountains that straddle the border between the Democratic Republic of Congo (DRC) and Uganda supply water to lakes that are a source of the White Nile as it flows north from Uganda into the Sudan. The mountains are also a hotspot of biodiversity featuring rare Afro-alpine fauna and flora.

Glaciers on the Rwenzori Mountains have receded rapidly over the last century. The estimated extent of icefields determined by field surveys and remote sensing, has declined from 6.5 km2 in 1906 to 1.0 km2 in 2003. If present trends continue, glaciers are expected to disappear from the Rwenzori Mountains entirely within the next two decades.

150 m retreat of the terminus of the Elena Glacier in the Rwenzori Mountains observed in photographs from (a) 31 January 2005 and (b) 22 April 2007. (photo illustration: Richard Taylor)
150 m retreat of the terminus of the Elena Glacier in the Rwenzori Mountains observed in photographs from (a) 31 January 2005 and (b) 22 April 2007. (photo illustration: Richard Taylor)

A definitive explanation of the causes of deglaciation in the Rwenzori Mountains is hindered by the absence of sustained meteorological observations around the icefields. There is, however, evidence of both rising air temperatures and reduced cloud cover as potential drivers of glacial recession; these influences are related as warmer air requires more water vapour to form clouds. At present, icefields occupy a narrow elevation range between 4800 m above mean sea level (mamsl) – the elevation of the 0°C isotherm – and the mountains’ highest summit at 5109 mamsl. The icefields are consequently highly sensitive to current and projected warming.

The Rwenzori Mountains are very wet with year-round rainfall in excess of 3 metres recorded in forest ecosystems below the glaciated summit. As meltwaters from dwindling icefields provide only a tiny contribution (<0.5%) to alpine rivers, river flow is much more strongly influenced by variability in precipitation than deglaciation. Observed warming in the Rwenzori Mountains serves, however, to intensify precipitation resulting in fewer but heavier rainfalls. This transition has been observed globally but is especially pronounced in the tropics.

Meltwater flow from the terminus of the Elena Glacier in the Rwenzori Mountains. (photo: Richard Taylor)
Meltwater flow from the terminus of the Elena Glacier in the Rwenzori Mountains. (photo: Richard Taylor)

As similarly reported in a GlacierHub post by Tsechu Dolma from the Himalayas, communities around the Rwenzori Mountains in Uganda and the DRC have experienced an increased frequency and intensity of flood events that have destroyed homes, crops, and transport links. In particular, the footbridges which connect communities are sometimes damaged or destroyed, making it difficult for children to attend schools, and farmers to travel to their fields or to markets. Longer droughts associated with the intensification of precipitation have also impaired crop production around the base of the mountains and increased demand for irrigation. Since projected warming as a result of climate change will amplify the risks of floods and droughts, the development of adaptive strategies to mitigate these impacts is critical.

This guest post was written by Richard Taylor a professor at University College London’s Department of Geography.  If you’d like to write a guest post for GlacierHub, contact us at glacierhub@gmail.com or @glacierhub on Twitter. 

Destroyed footbridge formerly used to cross the River Mubuku in the foothills of the Rwenzori Mountains near Kasese Town.
Destroyed footbridge formerly used to cross the River Mubuku in the foothills of the Rwenzori Mountains near Kasese Town. (photo: Richard Taylor)

Documentary “Snows of the Nile’ tracks disappearing Uganda glaciers

Snows of the Nile

Glaciers are melting everywhere, but none so much as the rare equatorial ones that lie on the border between the Democratic Republic of Congo and Uganda in east Africa.

The new documentary Snows of the Nile follows Neil Losin and Nate Dappen, two scientists and photographers whose ambitious expedition is to return to the original sites documented in  historical glacier photographs from the Uganda’s glaciers, the Rwenzoris. Retracing the steps of the Duke of Abruzzi’s legendary 1906 ascent, the images bear witness to a century of climate change. Losin and Dappen, who won a “Stay Thirsty Grant” from Dos Equis (yes, the beer), produced, filmed and edited the documentary.

Uganda’s glaciers, at the heart of Africa, are expected to completely disappear in a decade or two. The Bakonjo people call the Rwenzoris home. They rely on the glaciers not only as a source for water but also as an attraction that generates tourism revenue. Rapid deglaciation results in reduced access to water in rural areas. Women now have to walk longer distances to get water from rivers, lakes and wells, and there is no guarantee that the new sources of water are as clean as the glacial meltwater. Moreover, reduced water availability deepens frequent and prolonged droughts; food security is affected, as rural farmers heavily depend on rain for their crops. Deglaciation also results in a decline of mountain tourism, which leads men to travel long distances in the search for jobs. Moreover, the receding glaciers now contribute less to water flow in the Nyamwamba River, leading to noticeable declines in hydroelectric power.

A group of researchers from a Ugandan university and international organizations just returning from the Rwenzories have predicted the glaciers there may cease to exist in two decades, possibly as early as the mid-2020s, following an expedition to the mountains named the Doomed Glaciers of Africa expedition. Studies have shown that from 1906 to 2003, the area covered by glaciers has reduced from 7.5 square kilometers to less than 1 square kilometer -a small fraction of the original area.

Snows of the Nile and the researchers highlight the fragility of an equatorial glacier, in which all the ice in an the entire mountain range is disappearing. As is the case around the world, the future of the communities who rely on the glacial melt remains uncertain.

Snows of the Nile is available on iTunes and Vimeo.