Kilimanjaro Ice Core Records: Evidence of Holocene Climate Change in Tropical Africa

Abstract

Six ice cores from Kilimanjaro provide an ∼11.7-thousand-year record of Holocene climate and environmental variability for eastern equatorial Africa, including three periods of abrupt climate change: ∼8.3, ∼5.2, and ∼4 thousand years ago (ka). The latter is coincident with the “First Dark Age,” the period of the greatest historically recorded drought in tropical Africa. Variable deposition of F^– and Na⁺during the African Humid Period suggests rapidly fluctuating lake levels between ∼11.7 and 4 ka. Over the 20th century, the areal extent of Kilimanjaro's ice fields has decreased ∼80%, and if current climatological conditions persist, the remaining ice fields are likely to disappear between 2015 and 2020.