[en] On October 12, 2007, the Nobel peace price was awarded to Al Gore and to the less mediatized IPCC (intergovernmental panel on climate change). This awarding to a group of scientists may look surprising. However, it just reflects the fear that climatic change represents a threat for the international safety. It shows that any mastering action of this global warming involves a very strategical sector, the energy sector, and disturbs our ways of producing, of consuming and of transporting ourselves. It is of prime importance to maintain the dialogue between the supporters of the two opposite visions of the world with contradictory interests, since the climate topic is a strong source of potential conflicts. This is one of the missions of the IPCC, a group of experts elected by their peers to establish a state-of-the-art of the scientific knowledge about climate change. This original scientific institution intercedes here not as a judge but as a warrant of the truthfulness of the informations in domains where the knowledge remains fragile and disputed. This dossier presents the contribution of the IPCC (GIEC in French) to the climate change debate, and the CIRED, a mixed research unit involved in the sustainable development issue. (J.S.)