This data set contains methane (CH4) concentration data derived from the Greenland Ice Sheet Project II (GISP2) ice core. The methane concentration was measured from trapped gases in in samples from 309 depths in the upper 2810 m of the GISP2 ice core. The time period extends to 110,000 yBP. The data set consists of Depth (m), Methane (ppbV) and Gas Age (ka). Data are available in ASCII format via ftp from the World Data Center for Paleoclimatology.