Dominique Raynaud is a glaciologist and paleo-climatologist. His career at the CNRS has been mainly dedicated to studying the air trapped in the ice of Antarctica and Greenland and decoding his climate messages. His contributions cover areas such as the past altitude of ice caps using the air content of ice as a paleoaltimeter and a tool to constrain ice core chronologies, the isotopic composition of trapped air (18O and 15N), the study of the N2/O2 ratio, pioneering measurements of atmospheric CO in ice. His most famous contribution, with his team at the Laboratoire de Glaciologie et Géophysique de l'Environnement (LGGE), concerns the reconstruction of the composition of CO2 and CH4 and the understanding of the link between greenhouse gases and climate on the scale of glacial-interglacial cycles and putting into perspective their increase since the beginning of the industrial era. Dominique Raynaud was Director of the LGGE from 1995 to 2002. He has been a member of the Groupement intergouvernemental d’experts sur l’Évolution du Climat (GIEC) since 1992 and as such co-winner of the 2007 Nobel Peace Prize.