Geographers investigate lack of snow on Kilimanjaro
Tue, 03 Nov 2009 14:57:00 GMT
Two University of Portsmouth researchers have examined the potential link between changes in surface land-use (including deforestation) on the lower slopes of Mount Kilimanjaro and the loss of ice on the mountain summit.
Nicholas Pepin and Martin Schaefer, of the Department of Geography, spent eleven days surveying the mountain?s glaciers in the summer of 2008. The researchers, who revealed their findings at a news conference in Dar es Salaam, said that their research confirmed that the mountain ice sheets have continued to shrink over the last decade, substantiating earlier reported research which showed a decrease in area from 20 square kilometres in 1880 to two square kilometres in 2000.
They said the continuation of ice loss was likely to be a result of both local and regional factors. The researchers believe that deforestation due to extensive farming is a major contributor.
Deforestation of the mountain`s lower slopes will cause a drying of the local climate. Because the mountain is in the tropics, every day strong upslope winds develop as the sun heats the mountain. These winds transport moisture from the forest zone to the mountain summit which falls as snow. The result is that lots of the moisture at summit level is locally generated by the mountain, and does not come from the free atmosphere. Measurements on the mountain slopes have for the first time quantified the importance of locally generated moisture. Deforestation will reduce this moisture source.
In addition to the clearance of forests to give room for farm land, other factors that contribute to the problem include expansion of human settlements into forest lands, illegal logging and industrial activities. The background influence of large scale climate warming cannot be ignored, but on the whole increasing temperatures are held to be relatively unimportant in causing the rapid loss of ice.
The research on Mt Kilimanjaro is in collaboration with Doug Hardy of the Climate System Research Center at the University of Massachusetts and Dr Bill Duane at the University of Brunei. The researchers installed climate sensors at various elevations of the mountain to monitor the effects of the mountain?s thermal circulation on transporting moisture to the upper reaches of the mountain.