The relative roles of CO2 and palaeogeography in determining late Miocene climate: results from a terrestrial model–data comparison

• DOI: 10.5194/cp-8-1257-2012
• Publication Date: 2012-08-16T05:27:59Z
• Authors: C. D. Bradshaw; D. J. Lunt; R. Flecker; U. Salzmann; M. J. Pound; A. M. Haywood; J. T. Eronen
• Keywords: Palaeogeography; Proxy (statistics); Paleoclimatology

Abstract. The late Miocene palaeorecord provides evidence for a warmer and wetter climate than that of today, there is uncertainty in the palaeo-CO2 record at least 200 ppm. We present results from fully coupled atmosphere-ocean-vegetation simulations examine relative roles palaeogeography (topography ice sheet geometry) CO2 concentration determination through comprehensive terrestrial model-data comparisons. Assuming these data accurately reflect climate, palaeogeographic reconstruction used model robust, then indicate that: 1. Both atmospheric contribute to proxy-derived precipitation differences between modern reference climates. However contributions exibit synergy so do not add linearly. 2. vast majority temperature climates can only be accounted if we assume towards higher end range estimates.