East African Highlands

Most people do not associate Africa with cryosphere regions, yet the East African Highlands may have contained glaciers since the last glacier maximum 11,000 years ago.  Seasonal cryosphere, in the form of snow, exists on the highest peaks of East Africa as well as in the Drakensburg Range of South Africa, the Lesotho Mountains, and the Atlas Mountains in Morocco.  The only existing African glaciers today are on Mt. Kilimanjaro, Mt. Kenya, and three glacier systems in the Rwenzori (“Mountains of the Moon”) between Uganda and the Democratic Republic of Congo.  These glaciers likely covered around 25 km2 in total in the early 1900s; today they cover well under 4 km2, based on the most recent surveys (tracking of the Rwenzori is especially difficult, even by satellite) (Mölg et al. 2013; UNEP 2013).

The Rwenzori in 1906 contained 43 named glaciers, distributed across six peaks and estimated to be half of the glacial area in East Africa at the time (Taylor et al. 2006).  At its maximum during the last glacial period, the Kilimanjaro ice sheet covered over 400 km2 (Young and Hastenwrath 1987).    By 1912, when reliable observations began, Kilimanjaro’s glacier extent was 11.4 km2.  It had diminished to 1.8 km2 in 2011, losing nearly 90 percent of its extent over 100 years; this includes nearly 30 percent loss of the ice extent that was present in 2000 (Thompson et al. 2009; Cullen et al. 2002).    The latest estimates of Rwenzori are under 2 km2, and Mt. Kenya has retreated to about 0.1 km2.  These glaciers therefore are among the most rapidly receding in the world, losing between 80-90 percent of their surface area since observations began in the late 1800s. Few glaciologists expect these glaciers to survive past 2050, and some estimate a disappearance by 2030.

The connection between the retreat of these glaciers and anthropogenic climate change is very complex, as is the climate of East Africa generally.  Influences on the region arise from processes ranging from the Indian Ocean and seasonal monsoon (itself tied to El Nino) to winds off the Sahara and even from Antarctica.  Extensive research on Kilimanjaro indicates that a variety of factors, including changes in precipitation patterns and dryness in the region, seem the greatest factors contributing to glacial melt there over the past few decades (Mölg et al. 2009).    The role of temperature remains an area of active debate among tropical glaciologists, with different processes potentially contributing more or less to the different glaciers (Kaser et al. 2004).   and Kilimanjaro being perhaps an especially unique case (Mölg, et al. 2010).

Although the processes causing these shifts remain an area of debate, tropical glaciologists do broadly agree that climate change has impacted the rate of observed glacial loss in East Africa in the past few decades (Mölg et al 2010), ibid.   Summit ice cover on Kilimanjaro decreased by about one percent per year from 1912-1953, but had risen to 2.5 percent per year from 1989-2007.  Ice core studies on Kilimanjaro show clear evidence of surface glacier melt only in the upper 65 cm of the 49-meter core that spans around 11,000 years.  This may indicate that the climate conditions driving the loss of Kilimanjaro’s ice fields are relatively recent (Thompson, et al. 2009).

This region has generated some debate as to the impact of climate change on the spread of malaria, since the temperature-sensitive mosquito that carries the disease had been observed higher in East African mountain communities a decade ago.  Malaria has since decreased in the region, likely due to greater prevention efforts such as bed net distribution.  The spread of malaria in the late 1990s probably was caused by other factors; yet the mosquito’s range can increase as temperature rises, and local communities remain vigilant (Stern et al. 2011).

Glacier and snow melt form a very small portion of water resources in this region, with recent measurements showing them contributing at 2 percent or less (Taylor et al. 2009).    The rain forests along the sides of these peaks, and rainfall at those altitudes play the greatest role in East African water resource systems.  Whether the total loss of glaciers in the region will have any impact on these rainfall patterns at the forest level, while unlikely, remains open to debate (Mölg et al. 2012)

UNEP in 2012 noted an economic value to the existence of East African glaciers, noting that “…the major effects of the shrinking of these iconic glaciers will be the loss of ice that is part of the attraction to tourists… Glacier loss is likely to mean the loss of tourism revenues that are so vitally important to the economies of Kenya and Tanzania especially.”[1] Indeed, the greatest value of the small remaining African glaciers may lie primarily with their symbolic value to the global human community.

[1] UNEP Global Environmental Alert Service (2012).