Elevated Southern Hemisphere moisture availability during glacial periods
Date
2024
Authors
Weij, R.
Sniderman, J.M.K.
Woodhead, J.D.
Hellstrom, J.C.
Brown, J.R.
Drysdale, R.N.
Reed, E.
Bourne, S.
Gordon, J.
Editors
Advisors
Journal Title
Journal ISSN
Volume Title
Type:
Journal article
Citation
Nature, 2024; 626(7998):319-326
Statement of Responsibility
Rieneke Weij, J. M. Kale Sniderman, Jon D. Woodhead, John C. Hellstrom, Josephine R. Brown, Russell N. Drysdale, Elizabeth Reed, Steven Bourne and Jay Gordon
Conference Name
Abstract
Late Pleistocene ice-age climates are routinely characterized as having imposed moisture stress on low- to mid-latitude ecosystems1-5. This idea is largely based on fossil pollen evidence for widespread, low-biomass glacial vegetation, interpreted as indicating climatic dryness6. However, woody plant growth is inhibited under low atmospheric CO2 (refs. 7,8), so understanding glacial environments requires the development of new palaeoclimate indicators that are independent of vegetation9. Here we show that, contrary to expectations, during the past 350 kyr, peaks in southern Australian climatic moisture availability were largely confined to glacial periods, including the Last Glacial Maximum, whereas warm interglacials were relatively dry. By measuring the timing of speleothem growth in the Southern Hemisphere subtropics, which today has a predominantly negative annual moisture balance, we developed a record of climatic moisture availability that is independent of vegetation and extends through multiple glacial-interglacial cycles. Our results demonstrate that a cool-moist response is consistent across the austral subtropics and, in part, may result from reduced evaporation under cool glacial temperatures. Insofar as cold glacial environments in the Southern Hemisphere subtropics have been portrayed as uniformly arid3,10,11, our findings suggest that their characterization as evolutionary or physiological obstacles to movement and expansion of animal, plant and, potentially, human populations10 should be reconsidered.
School/Discipline
Dissertation Note
Provenance
Description
Published online: 7 February 2024
Access Status
Rights
© The Author(s), under exclusive licence to Springer Nature Limited 2024