As part of the Greenland Ice Sheet Project, this investigation will carbon-14 date atmospheric gases trapped in relatively small (a few kg) samples of polar ice cores. The technique would be to place the ice in a vacuum system and the sublime the ice onto the surface of a -80C degrees cold trap. The gas released by this procedure would be passed through a multipass trap held at liquid- nitrogen temperature, which would enable all the carbon dioxide to be recovered. The CO2 sample so obtained would be accurately diluted and converted into a graphite target for 14C determination by accelerator mass spectrometry. The atmospheric gases other than CO2 (and N2O) would be trapped on a molecular sieve and be available for other studies related to the paleoclimatology of the northern hemisphere.