Sustainable mountain development in East Africa in a changing climate

temperature, evaporation, precipitation and humidity (Campell, 2008; Taylor et al., 2009; Mölg et al., 2009; Hastenrath, 2010; UNEP, 2012). According to Taylor et al. (2006), the glaciers on the Rwenzori Mountains have decreased from a total of 6.5 km² in 1906 to about 1 km² in 2003. From 1987 to 2003, the total area of the glaciers decreased by about 50 per cent. If the current rate of recession continues, these glaciers will disappear within the next two decades. The same study argues that the rapid recession of Rwenzori’s glaciers can be attributed to the increase in temperature of 0.5 °C per decade documented since the 1960s in areas close to the mountain range. An increase in temperature is also believed to be the reason for the shrinking of Mount Kenya’s glaciers (Campell, 2008). On Mount Kilimanjaro, a reduction in precipitation is seen as the main reason for the shrinking of its glaciers in recent decades (Mölg et al., 2009). Records indicate that precipitation has declined in East Africa and that the higher altitudes, in particular, have become drier. Data from three weather stations on the southern slope of Kilimanjaro show that precipitation decreased by up to 39 per cent between 1911 and 2004 (Hemp, 2005). Globally, water from melting glaciers provides fresh water to millions of people. However, in East Africa, receding glaciers are of little concern for future water supply. Water from glaciers is relatively insignificant for total river flows in the region. For example, a study by Taylor et al. (2009), found that meltwater from the glaciers onSpeke andElana in theRwenzoriMountains contributes less than 2 per cent of the discharge of the Mubuku River. Similar findings are likely for the glaciers on Mount Kenya and Kilimanjaro. The main source of fresh water in the Mubuku River is rainwater, which the area receives in abundance – about 2,340- 2,600 mm a year (Taylor et al., 2009).

Mount Kenya, Kenya

Glacial retreat Melting glaciers have provided the most compelling evidence of climate change globally. East Africa is the only subregion of Africa where glaciers are found and only on the highest summits. They are scattered across the peaks of Mount Kilimanjaro, Mount Kenya and the Rwenzori Mountains (Mount Stanley, Speke and Baker). It is not without reason that the media and scientists alike are calling this the last chance to see the glaciers of Africa. Since the 1990s, Africa’s glaciers have lost 80 per cent of their surface area and, if the current rate of recession continues, it is very likely that they will disappear within a few decades (UNEP, 2014). Six square kilometres of glaciers is all that is left (Kohler and Masseli, 2012). The glaciers started to retreat at the beginning of the 1880sduetoreductionsinprecipitationandcloudcover – this resulted in lower rates of snow accumulation and higher levels of solar radiation which further increased the rate of melting (Hastenrath, 2010). Scientific studies of current glacial retreat do not agree, however, on the main drivers, which include air

by 30 per cent or more by 2050. Several studies presented in the IPCC’s Fifth Assessment Report (Niang et al. 2014) find that Kenyan rivers such as the Mara, the Nyando and the Tana can expect an increase in water flow during the second half of this century. Similarly, a study by Rockström et al (2009), which assesses the impact of climate change on water availability towards 2050, finds that water availability will increase in most of the subregion. Uganda, Burundi and Rwanda, however, may experience a reduction in water availability, to between 500 and 1,000 m³ per capita per annum, but this will largely be due to their rapid population growth. Ethiopia is also likely to experience a decrease in water availability, but this will remain between 1,300 and 1,500 m³ per capita per annum. A study by Williams and Funk (2011) finds that the eastern part of the Ethiopian Highlands will experience reduced precipitation due to climate change and, as a consequence, the river flow of the Blue Nile River will decline towards the end of the century (McCartney and Girmba, 2012). Similar findings have been reported by Abdo et al. (2009).

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