title: The tropical lapse rate steepened during the Last Glacial Maximum.
abstract: The gradient of air temperature with elevation (the temperature lapse rate) in the tropics is predicted to become less steep during the coming century as surface temperature rises, enhancing the threat of warming in high-mountain environments. However, the sensitivity of the lapse rate to climate change is uncertain because of poor constraints on high-elevation temperature during past climate states. We present a 25,000-year temperature reconstruction from Mount Kenya, East Africa, which demonstrates that cooling during the Last Glacial Maximum was amplified with elevation and hence that the lapse rate was significantly steeper than today. Comparison of our data with paleoclimate simulations indicates that state-of-the-art models underestimate this lapse-rate change. Consequently, future high-elevation tropical warming may be even greater than predicted.
authors.affiliation: Department of Earth, Environmental, and Planetary Sciences, Brown University, 324 Brook Street, Box 1846, Providence, RI 02912, USA.
authors.forename: Shannon E
authors.initials: SE
authors.lastname: Loomis
authors.affiliation: Department of Earth, Environmental, and Planetary Sciences, Brown University, 324 Brook Street, Box 1846, Providence, RI 02912, USA.; Institute at Brown for Environment and Society, Brown University, Providence, RI 02912, USA.
authors.forename: James M
authors.identifier: 0000-0002-1329-4613
authors.initials: JM
authors.lastname: Russell
authors.affiliation: Department of Biology, Limnology Unit, Ghent University, K.L. Ledeganckstraat 35, 9000 Ghent, Belgium.
authors.forename: Dirk
authors.initials: D
authors.lastname: Verschuren
authors.affiliation: Cooperative Institute for Research in Environmental Sciences, University of Colorado at Boulder, Boulder, CO 80305-3328, USA.; National Centers for Environmental Information, National Oceanic and Atmospheric Administration, Boulder, CO 80305-3328 USA.
authors.forename: Carrie
authors.identifier: 0000-0002-1635-5469
authors.initials: C
authors.lastname: Morrill
authors.affiliation: Department of Biology, Limnology Unit, Ghent University, K.L. Ledeganckstraat 35, 9000 Ghent, Belgium.; Department of Earth Sciences, Royal Museum for Central Africa, Leuvensesteenweg 13, 3080 Tervuren, Belgium.
authors.forename: Gijs
authors.initials: G
authors.lastname: De Cort
authors.affiliation: Department of Marine Microbiology and Biogeochemistry, NIOZ Royal Netherlands Institute for Sea Research, P.O. Box 59, 1790 AB Den Burg, Texel, Netherlands.; Faculty of Geosciences, University of Utrecht, P.O. Box 80.021, 3508 TA Utrecht, Netherlands.
authors.forename: Jaap S
authors.identifier: 0000-0002-8683-1854
authors.initials: JS
authors.lastname: Sinninghe Damsté
authors.affiliation: Department of Geology, University of Nairobi, P.O. Box 30197-00100, Nairobi, Kenya.; Institute for Climate Change and Adaptation, University of Nairobi, Nairobi, Kenya.
authors.forename: Daniel
authors.identifier: 0000-0001-6080-5802
authors.initials: D
authors.lastname: Olago
authors.affiliation: Department of Biology, Limnology Unit, Ghent University, K.L. Ledeganckstraat 35, 9000 Ghent, Belgium.; Belgian Biodiversity Platform, Royal Belgian Institute for Natural Sciences, Vautierstraat 29, 1000 Brussels, Belgium.
authors.forename: Hilde
authors.initials: H
authors.lastname: Eggermont
authors.affiliation: College of Science, Swansea University, Singleton Park, Swansea SA32 7QD, UK.
authors.forename: F Alayne
authors.identifier: 0000-0003-1149-9110
authors.initials: FA
authors.lastname: Street-Perrott
authors.affiliation: Department of Earth Sciences, Dartmouth College, Hanover, NH 03750, USA.
authors.forename: Meredith A
authors.identifier: 0000-0001-8163-3907
authors.initials: MA
authors.lastname: Kelly
keywords: Africa; Climate Change; Paleoclimate; Tropics; glaciers; temperature