Summary
During the transition from the last glacial maximum to the present warm interglacial a sequence of large, hemispheric, climate changes took place: the Bølling‐Allerød and Younger Dryas in the north and the Antarctic Cold Reversal in the south. Accurate information on the phase relationship of these climate changes between the two hemispheres is a key to understanding the Earth’s climate dynamics. Here, we present a new climate chronology for the transition derived from the very high accumulation Law Dome ice core, East Antarctica. The Law Dome chronology is synchronized with precisely dated Greenland records from GRIP and GISP by aligning global methane signals. The chronology shows unequivocally that the onset of the Antarctic Cold Reversal at Law Dome occurred prior to the Bølling transition. The ACR lead ranges from approximately 100 – 400 years under a range of accumulation rate scenarios. The synchronization also shows that the termination of the Antarctic Cold Reversal occurred approximately 1100 years prior to the onset of the Younger Dryas. The conventional view of the phasing of climate changes during the deglaciation is that the onset of the Antarctic Cold Reversal and the Bølling transition were near synchronous. These results show a definitive southern hemisphere lead and appear incompatible with the hypothesis that the Antarctic Cold Reversal was a direct response to an abrupt change in North Atlantic thermohaline circulation.