The Laboratoire de Météorologie Dynamique (LMD) is a joint research unit which brings together the CNRS, the École Polytechnique, the École Normale Supérieure (ENS) and the Université Pierre et Marie Curie in Paris. The LMD has a total of 180 employees, including 50 scientists and about 70 PhD students and post-docs. Main research themes at the LMD include studying climate evolution, the effects of increasing anthropogenic emissions and the physical processes underlying climate variability. The group at ENS, with ~40 members, has a long tradition of research in atmospheric dynamics. Within the ENS, the LMD is part of the Geosciences Department, which includes a group working in geophysics in addition to the atmospheric physics. The LMD is part of the Institut Pierre-Simon Laplace (IPSL) which is a joint action initiated by six major laboratories in the Paris area. Together these laboratories have expertise in almost all the fields of atmospheric, oceanic and climate science. A particular strength of the IPSL is the ability to build collaborative projects among scientists of different areas of expertise. The IPSL Earth System Model, where the LMD is in charge of the atmospheric component, is one of the main models used by the CMIP / IPCC assessments of climate change. The Climate modelling Group of LMD, in nearby Jussieu campus, is at the core of the development of the LMDz GCM.