Introduction to ‘Antarctic cryosphere and Southern Ocean climate evolution (Cenozoic–Holocene)’

Antarctic region has profoundly affected the global climates of the Cenozoic, influencing sea levels, atmospheric composition and dynamics, and ocean circulation. According to IPCC-2007 (IPCC, 2007) worst-case scenario projections, global annual mean temperatures by 2100 are likely to exceed those that have been experienced by the Earth in the last 40 myr when the Antarctic Ice Sheet may have first developed. This implies that the Ice Sheet may become unsustainable, with huge implications for global sea levels. A greater understanding of past changes in this region is crucial in forming a better view of future global environmental change and to predict the role of the Antarctic ice sheet in the future. For several decades international efforts have been made to determine the glacial and climate history of Antarctica and the Southern Ocean. Sediment cores drilled in and around Antarctica have been extracted onboard ships and over the floating perennial ice that borders the ice sheets (e.g., see Florindo et al. (2003b) for a review of the recent history of circum-Antarctic drilling by the Ocean Drilling Program and the Cape Roberts Project, and see Hambrey and Barrett (1993) for a more comprehensive review of earlier drilling in the Ross Sea region). In addition, there have been numerous terrestrial geological expeditions to ice-free areas and nunataks close to the margin of the ice sheet. This special issue of Palaeo3 has developed largely from papers presented in an all day session of presentations and posters at the EGU meeting in Vienna (02–07 April, 2006), and at the XXIX SCAR open science meeting in Hobart, Tasmania (08–20 July, 2006). These papers present results on geoscience data aimed at improving our understanding of the behaviour of the Antarctic Ice Sheet and the climate of the region. Like the past three special issues on the theme of Antarctic Climate Evolution ([Florindo et al., 2003a], Florindo et al., 2005 In: F. Florindo, D.M. Harwood and G.S. Wilson, Editors, Long Term Changes in Southern High-latitude Ice Sheets and Climate, the Cenozoic History, Global and Planetary Change vol. 45 (1–3) (2005), pp. 1–260.[Florindo et al., 2005] and [Barrett et al., 2006]), this special issue is linked to the Antarctic Climate Evolution (ACE) project. It is an initiative of the Scientific Committee on Antarctic Research (SCAR) to investigate the climate and glacial history of Antarctica by linking climate and ice sheet modelling studies with geophysical surveys and geological studies on and around the Antarctic continent (www.scar.org/researchgroups/geoscience/ace; http://www.ace.scar.org).Published1-72.2. Laboratorio di paleomagnetismoJCR Journalreserve