Introduction

The Pliocene epoch (~2.6-5.3 million years ago) is one of the best resolved examples of a climate state in long-term equilibrium with current or predicted near-future atmospheric CO2 concentrations, characterised by a globally warmer climate, reduced continental ice volume, and reduced ocean/atmosphere circulation intensity. PlioVAR aims to co-ordinate a synthesis of late Pliocene terrestrial and marine data at orbital and sub-orbital scale resolution over marine isotope stages M2-KM3 (glacial to interglacial transition) and the intensification of northern hemisphere glaciation (McClymont et al., 2017). A specific focus is on integrating records with a robust stratigraphy in order to accurately characterise the spatial and temporal variability of Pliocene climate and underpin future data/model comparisons.

Key findings

KM5c

McClymont et al. (2020) (Climate of the Past) synthesises ocean temperatures during a 20 kyr timeslice of KM5c (3.195-3.215 Ma) when both seasonal and regional distributions of solar insolation were similar to modern. With atmospheric CO2 concentrations in KM5c also similar to today and those projected for 2100 CE by IPCC Representative Concentration Pathway (RCP) scenarios RCP2.6 and RCP4.5, the interval can be used as an analogue of future climate change and associated changes in the marine system. A list of sites and data used in this paper can be found in the KM5c SST database.

Onset and Intensification of Northern Hemisphere Glaciation

McClymont, Ho et al. (2023) (Reviews in Geophysics) assesses the spatial and temporal variability of ocean temperatures and ice-volume indicators through the late Pliocene and early Pleistocene (from 3.3 to 2.4 Ma) over the onset and intensification of Northern Hemisphere Glaciation (iNHG). These analyses demonstrated the complex, non-uniform and globally asynchronous nature of climate changes during this time period and the way in which shifting ocean gateways and ocean circulation changes may have pre-conditioned the later evolution of ice sheets with falling atmospheric pCO2. A list of sites and data used in this paper can be found in the iNHG database.

Organisation

PlioVAR is being driven by Erin McClymont, Heather Ford and Sze Ling Ho, with contributions from the regional synthesis leaders (see below). If you have new data or publications which have emerged in recent months or which will come out in the future, please contact us so that we can include it into our future synthesis work.