New estimates of glacier retreat on Kilimanjaro, Mount Kenya and in the Rwenzori Range from high-resolution satellite imagery

Over the last decades, the retreat of the glaciers on Kilimanjaro has been portrayed as a beacon of climate change. The decline in glacier area within the 20th century, however, is evident for all tropical glaciers in East Africa, including those of Mount Kenya and the Rwenzori Range. Being mainly controlled by the hygric seasonality of these high-altitude regions, they are particularly valuable indicators of climate variability and climate change. While studies have focused on Kilimanjaro and Mount Kenya and have not considered the Rwenzori Range for nearly two decades, there are no current overall estimates of the remaining glacierization in East Africa. Therefore, the present study provides insights into the most recent glacier extents of all three mountain regions from a manual, multitemporal analysis of high-resolution satellite images for the years 2021/2022. Accordingly, the glacierization in East Africa is estimated to be 1.36 km² with a glacier area of 0.97 km² on Kilimanjaro, 0.069 km² on Mount Kenya and 0.38 km² in the Rwenzori Range. Compared to previous estimations, the overall area has declined by more than a half of its early 21^st century extent, with an increased retreat rate in the Rwenzori Range and Mount Kenya. These recent results demonstrate the continuing influence of retreat processes that include high-elevation snowfall changes and, therefore, are related to the changes in climatic conditions on a larger scale.

The 28th IUGG General Assembly (IUGG2023) (Berlin 2023)