Abstract The Antarctic and Greenland ice contains an almost direct record of past atmospheric CH 4 . The record over the last 200 years reveals a spectacular 150% increase of the CH 4 atmospheric mixing ratio since pre-industrial times. At the scale of a glacial-interglacial cycle the record shows a remarkable correlation with climatic changes, with high (low) CH 4 levels during warm (cold) periods. A striking feature of the glacial-interglacial CH 4 record is the presence of large and abrupt (at the scale of a century or less) changes during the last glaciation and glacial-interglacial transition. The classical interpretation for the origin of CH 4 changes prior to the industrial era involves mainly the wetland source. In the context of gas hydrates the question is to know whether the past ice-core record contains fingerprints of catastrophic hydrate release (CHR). We currently conclude that the available record shows no evidence for CHR but additional ice-core analyses are necessary to reach a more definitive conclusion.