Pronounced summer warming in northwest Greenland during the Holocene and Last Interglacial

Jamie M. McFarlin*, Yarrow Axford, Magdalena R. Osburn, Meredith A. Kelly, Erich C. Osterberg, Lauren B. Farnsworth

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

23 Scopus citations

Abstract

Projections of future rates of mass loss from the Greenland Ice Sheet are highly uncertain because its sensitivity to warming is unclear. Geologic reconstructions of Quaternary interglacials can illustrate how the ice sheet responded during past warm periods, providing insights into ice sheet behavior and important tests for data-model comparisons. However, paleoclimate records from Greenland are limited: Early Holocene peak warmth has been quantified at only a few sites, and terrestrial sedimentary records of prior interglacials are exceptionally rare due to glacial erosion during the last glacial period. Here, we discuss findings from a lacustrine archive that records both the Holocene and the Last Interglacial (LIG) from Greenland, allowing for direct comparison between two interglacials. Sedimentary chironomid assemblages indicate peak July temperatures 4.0 to 7.0 °C warmer than modern during the Early Holocene maximum in summer insolation. Chaoborus and chironomids in LIG sediments indicate July temperatures at least 5.5 to 8.5 °C warmer than modern. These estimates indicate pronounced warming in northwest Greenland during both interglacials. This helps explain dramatic ice sheet thinning at Camp Century in northwest Greenland during the Early Holocene and, for the LIG, aligns with controversial estimates of Eemian warming from ice core data retrieved in northern Greenland. Converging geologic evidence for strong LIG warming is challenging to reconcile with inferred Greenland Ice Sheet extent during the LIG, and the two appear incompatible in many models of ice sheet evolution. An increase in LIG snowfall could help resolve this problem, pointing to the need for hydroclimate reconstructions from the region.

Original languageEnglish (US)
Pages (from-to)6357-6362
Number of pages6
JournalProceedings of the National Academy of Sciences of the United States of America
Volume115
Issue number25
DOIs
StatePublished - Jun 19 2018

Keywords

  • Eemian
  • Greenland
  • Holocene thermal maximum
  • Last Interglacial
  • Paleotemperature

ASJC Scopus subject areas

  • General

Fingerprint

Dive into the research topics of 'Pronounced summer warming in northwest Greenland during the Holocene and Last Interglacial'. Together they form a unique fingerprint.

Cite this