Tuesday, February 26, 2013

New paper finds sea levels rose twice as fast to 8 meters higher than the present during last interglacial

A new paper published in Geophysical Journal International finds that during the last interglacial, global sea levels rose more than twice as fast as the present rate, to more than 8 meters higher than the present. According to the authors, the maximum 1000-year-average rate of sea level rise during the last interglacial exceeded 6 mm/yr, which is double the rate claimed by the IPCC of 3.1 mm/yr, and 5 times the rate claimed by NOAA of ~ 1.2 mm/yr. The paper adds to many other peer-reviewed studies demonstrating there is nothing unusual, unnatural, or unprecedented regarding current sea level rise, and that there is no evidence of a human influence on sea levels.

Full paper here

note higstand figures and 1000-yr-average global sea level rise derived from text in section 3.1 using the average of the two most likely estimates.

A probabilistic assessment of sea level variations within the last interglacial stage

Robert E. Kopp 1, Frederik J. Simons2, Jerry X. Mitrovica3, Adam C. Maloof2 andMichael Oppenheimer 2,4

+Author Affiliations
1Department of Earth and Planetary Sciences and Rutgers Energy Institute, Rutgers University, Piscataway, NJ 08854, USA. E-mail: robert.kopp@rutgers.edu
2Department of Geosciences, Princeton University, Princeton, NJ 08544, USA
3Department of Earth and Planetary Sciences, Harvard University, Cambridge, MA 02138, USA
4Woodrow Wilson School of Public and International Affairs, Princeton University, Princeton, NJ 08544, USA

Summary

The last interglacial stage (LIG; ca. 130–115 ka) provides a relatively recent example of a world with both poles characterized by greater-than-Holocene temperatures similar to those expected later in this century under a range of greenhouse gas emission scenarios. Previous analyses inferred that LIG mean global sea level (GSL) peaked 6–9 m higher than today. Here, we extend our earlier work to perform a probabilistic assessment of sea level variability within the LIG highstand. Using the terminology for probability employed in the Intergovernmental Panel on Climate Change assessment reports, we find it extremely likely (95 per cent probability) that the palaeo-sea level record allows resolution of at least two intra-LIG sea level peaks and likely (67 per cent probability) that the magnitude of low-to-high swings exceeded 4 m. Moreover, it is likely that there was a period during the LIG in which GSL rose at a 1000-yr average rate exceeding 3 m kyr−1, but unlikely (33 per cent probability) that the rate exceeded 7 m kyr−1 and extremely unlikely (5 per cent probability) that it exceeded 11 m kyr−1. These rate estimates can provide insight into rates of Greenland and/or Antarctic melt under climate conditions partially analogous to those expected in the 21st century.

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