J. P. Steffensen et al., Science 2008, High-resolution Greenland ice core data show abrupt climate change happens in few years

Science, published online June 19, 2008

High-resolution Greenland ice core data show abrupt climate change happens in few years

J. P. Steffensen et al.


Abstract

The last two abrupt warmings at the onset of our present warm interglacial period, interrupted by the Younger Dryas cooling event, are investigated in high temporal resolution from the Greenland NGRIP ice core. The deuterium excess, a proxy of Greenland precipitation moisture source, switches mode within 1 to 3 years over these transitions and initiates a more gradual change (50 years) of the Greenland air temperature as recorded by water stable isotopes. The onsets of both abrupt Greenland warmings are slightly preceded by decreasing Greenland dust deposition, reflecting wetting of Asian deserts. A northern shift of the ITCZ could be the trigger of these abrupt shifts of northern hemisphere atmospheric circulation resulting in 2 to 4K changes in Greenland moisture source temperature from one year to the next.

Link to abstract:  http://www.sciencemag.org/cgi/content/abstract/1157707v1