GFI/BCCR Seminar: Assessing Late Pliocene warming and climate variability with multi-proxy data and climate model simulations

Ulrich Saltzman

Assessing Late Pliocene warming and climate variability with multi-proxy data and climate model simulations

Abstract
The talk will present results from the international PRISM/PLioMIP programme which focusses on the global reconstruction of climate and environments of the warm late Pliocene world, ca 3.6–2.6 million years ago, using geological data and models. The Late Pliocene is widely regarded as an accessible geological interval to understand climate processes of a warmer world. The talk will present a global data set of confidence-assessed, proxy-based surface temperature estimates and vegetation reconstructions to assess the ability of eight global climate models to simulate warm climates of the Pliocene Epoch. We show that model-predicted terrestrial and sea surface temperatures reveal a substantial cold bias in the Northern Hemisphere high latitudes. Particularly strong data–model mismatches of mean annual temperatures exist in northern Russia (up to 18°C) and the North Atlantic. Our model sensitivity tests identify insufficient temporal constraints and age resolution hampering the accurate configuration of model boundary conditions as an important factor impacting on data-model discrepancies. Our data-model comparison highlights the need for high resolution studies to further understand the mechanism and variability of climate in a warmer-than-present world.