Quaternary Science Reviews 20 (2001) 583}589 Manfred Mudelsee Institute of Meteorology, University of Leipzig, Stephanstr. 3, D-04103 Leipzig, Germany Abstract The phase relations (leads/lags) among atmospheric CO2 content, temperature and global ice volume are key to understanding the causes of glacial-interglacial (G-IG) climate transitions. Comparing the CO2 record with other proxy variables from the Vostok ice core and stacked marine oxygen isotope records, allows the phase relations among these variables, over the last four G-IG cycles, to be estimated. Lagged, generalized least-squares regression provides an efficient and precise technique for this estimation. Bootstrap resampling allows account to be taken of …