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Credit: Image credit: Ivan Haigh (University of Southampton, Southampton, UK)
A study finds fluctuations in sea level and ice sheet size during a period when atmospheric carbon dioxide levels were similar to present levels. Among the consequences of rising atmospheric carbon dioxide and anthropogenic climate change are the melting of ice sheets and the associated sea level rise, although the response of the East Antarctic Ice Sheet (EAIS) to a warming climate is unclear. Kim A. Jakob and colleagues reconstructed North Atlantic deep ocean temperatures, global sea level, and ice volume for a period around 2.75 to 2.4 million years ago. During that period, the range of atmospheric carbon dioxide levels was similar to the last few hundred years through the present time. The results revealed glacial and interglacial cycles, with global sea level largely driven by the size of Northern Hemisphere ice sheets. Sea level peaks suggested melting of the EAIS prior to around 2.53 million years ago, but reduced sea levels after that time suggested that the lowering of sea level due to the growth of Northern Hemisphere ice sheets may have acted to stabilize the EAIS by limiting its exposure to warm ocean water. According to the authors, the findings highlight EAIS vulnerabilities under a warming climate.
Article #20-04209: "A new sea-level record for the Neogene/Quaternary boundary reveals transition to a more stable East Antarctic Ice Sheet," by Kim A. Jakob et al.
MEDIA CONTACTS: Oliver Friedrich, Heidelberg University, GERMANY; e-mail: oliver.friedrich@geow.uni-heidelberg.de; Paul Wilson, University of Southampton, UNITED KINGDOM; e-mail: paw1@noc.soton.ac.uk
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Journal
Proceedings of the National Academy of Sciences