New paper finds another non-hockey-stick in the Mediterranean Sea

A paper published today in The Holocene reconstructs temperatures in the central Mediterranean Sea over the past 2,500 years and finds another non-hockey-stick demonstrating warmer temperatures during the Medieval Warming Period and Roman Warming Period than at the end of the record in the year 2000.

d18O is a proxy for temperature and precipitation and shows warmer temperatures during the Medieval Warming Period and Roman Warming Period than at the end of the record in 2000. Graph source is a pre-print of the paper below.

Climate of the past 2500 years in the Gulf of Taranto, central Mediterranean Sea: A high-resolution climate reconstruction based on δ¹⁸O and δ¹³C of Globigerinoides ruber (white)

1. Anna-Lena Grauel1
2. Marie-Louise S Goudeau2
3. Gert J de Lange2
4. Stefano M Bernasconi1

1. ¹Geological Institute, ETH Zurich, Switzerland
2. ²Institute of Earth Sciences - Geochemistry, Geosciences, Utrecht University, The Netherlands

1. Anna-Lena Grauel, Department of Earth Sciences, University of Cambridge, Downing Street, Cambridge CB2 3EQ, UK. 

Abstract

We present a high-resolution isotope stratigraphy based on Globigerinoides ruber (white) over the past 2500 years in the Gulf of Taranto, central Mediterranean. G. ruber (white) reflects summer conditions in the Gulf of Taranto but is influenced by two major surface water masses: the Western Adriatic Current (WAC) and the Ionian Surface Water (ISW) and their variations on a decadal to multicentennial scale. Our analysis of the δ¹³C and δ¹⁸O of G. ruber (white) allows the distinction of several climatic periods: the ‘Roman Warm Period’ (RWP) (450–0 BC), with relatively wet and warm conditions and a higher influence of the WAC; the ‘Roman Classical Period’ (RCP) (AD 1–200) characterized by salinity increase resulting from circulation changes; the ‘Dark Ages Cold Period’ (DCP) (AD 500–750), where wetter conditions in the Gulf of Taranto region are coherent with an increase dominance of the WAC; the ‘Medieval Warm Period’ (MWP), with wet and warm conditions in the first, and a gradual drying in the second half; and finally, the transition from the MWP to the ‘Little Ice Age’ (LIA), which is characterized by continuing dry conditions.