File:Ice Age Temperature changes.JPG

Source: Wikimedia Commons

http://commons.wikimedia.org/wiki/Image:Ice_Age_Temperature.png

This figure shows the Antarctic temperature changes during the last several glacial/interglacial cycles of the present ice age and a comparison to changes in global ice volume. The present day is on the left.

The first two curves shows local changes in temperature at two sites in Antarctica as derived from deuterium isotopic measurements (&delta;D) on ice cores (EPICA Community Members 2004, Petit et al. 1999). The final plot shows a reconstruction of global ice volume based on &delta;18O measurments on benthic foraminifera from a composite of globally distributed sediment cores and is scaled to match the scale of fluctuations in Antarctic temperature (Lisiecki and Raymo 2005). Note that changes in global ice volume and changes in Antarctic temperature are highly correlated, so one is a good estimate of the other, but differences in the sediment record do no necessarily reflect differences in paleotemperature. Horizontal lines indicate modern temperatures and ice volume. Differences in the alignment of various features reflect dating uncertainty and do not indicate different timing at different sites.

The Antarctic temperature records indicate that the present interglacial is relatively cool compared to previous interglacials, at least at these sites. The Liesecki & Raymo (2005) sediment reconstruction does not indicate signifcant differences between modern ice volume and previous interglacials, though some other studies do report slightly lower ice volumes / higher sea levels during the 120 ka and 400 ka interglacials (Karner et al. 2001, Hearty and Kaufman 2000).

It should be noted that temperature changes at the typical equatorial site are believed to have been significantly less than the changes observed at high latitude.