This d13Catm data set covers the temporal range (24.4 kyr to 0.4 kyr BP) of the individual data sets and is obtained from a Monte Carlo bootstrap approach providing d13Catm values in yearly evolution. This approach allowed for detection of analytical outliers, which are incompatible with the low-pass filtering inherent to the bubble enclosure process in polar ice. With this method, we were able to derive a robust d13Catm record. For details on the method see the Supplementary Information of the paper.