Detection and Attribution of climate change for the glaciers on Kilimanjaro: Targeting the processes at regional and local scales
Atmospheric Science
Final Report Abstract
Shrinking glaciers are obvious signs of climate change effects on the world's highmountain regions. The exact mechanisms that transfer global climate change to the local changes in high mountains and to glacier mass are difficult to decipher due to the complexity of the climate system. This applies, in particular, to the question of what local changes are natural or due to human-made climate change. The present project aimed to study such mechanisms for the now very small glaciers on Africa's highest mountain, Kilimanjaro, which are considered a global indicator of climate change in the tropics. Meteorological measurements at high altitude on Kilimanjaro provided the basis, and several climate models of different scales (regional, global) contributed the remaining "big data" set, which makes the above-mentioned decoding possible in the first place. Our results show that (1) the global climate models have to be chosen very carefully as a starting point (for which we developed a new selection method), (2) the local meteorological conditions in the summit zone and their daytime and seasonal variabilities strongly depend on the characteristics of the air flow along the mountain slope (for which we performed regional climate simulations on supercomputers), and (3) the local climate in this highest glaciated zone depends on the degree of the socalled "external anthropogenic forcing", i.e. the strength of the climate impact of human activities (we also used machine learning to reveal this relationship). While moderate emission scenarios in the sense of the Paris Climate Agreement will stabilize the climate at the summit of Kilimanjaro in the coming decades, high emissions will lead to further climatic trends and changes throughout the 21st century. These results confirm that controlling human emissions through climate protection will have a direct impact on the ice masses in the high mountains of our planet.
Publications
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Mesoscale atmospheric circulation controls of local meteorological elevation gradients on Kersten Glacier near Kilimanjaro summit. Earth System Dynamics, 11(3), 653-672.
Mölg, Thomas; Hardy, Douglas R.; Collier, Emily; Kropač, Elena; Schmid, Christina; Cullen, Nicolas J.; Kaser, Georg; Prinz, Rainer & Winkler, Michael
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Tropical Glaciers. Springer Textbooks in Earth Sciences, Geography and Environment, 483-495. Springer International Publishing.
Mölg, Thomas & Kaser, Georg
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Tropische Gletscher: Ostafrika. In: Lozán J.L. et al. (eds) Warnsignal Klima: Hochgebirge im Wandel. Verlag Wissenschaftliche Auswertungen in Kooperation mit GEO Magazin-Hamburg
Prinz R. & Mölg T.
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General Circulation Model Selection Technique for Downscaling: Exemplary Application to East Africa. Journal of Geophysical Research: Atmospheres, 126(6).
Pickler, C. & Mölg, T.
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A mid-troposphere perspective on the East African climate paradox. Environmental Research Letters, 17(8), 084041.
Mölg, Thomas & Pickler, Carolyne
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Manual detection of glacier extents on Kilimanjaro, Mount Kenya, and in the Rwenzori Range in 2021/2022 [dataset]
Hinzmann A., Mölg T., Braun M.H., Cullen N.J., Hardy D.R., Kaser G. & Prinz R.
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Tropical glacier loss in East Africa: recent areal extents on Kilimanjaro, Mount Kenya, and in the Rwenzori Range from high-resolution remote sensing data. Environmental Research: Climate, 3(1), 011003.
Hinzmann, Anne; Mölg, Thomas; Braun, Matthias; Cullen, Nicolas J.; Hardy, Douglas R.; Kaser, Georg & Prinz, Rainer
