Abstract : Complexity and diversity caracterise the environmental problems : complexity and diversity of the misconceptions on nature and environment, of the discipline, of the stakes which all determinate many different ways to intend environment. Those approachs are going to determinate also the different forms of environmental mediation in the museum. For example, some museums will have a naturalist approach of environment and will consider only the nature's problems, whereas others will consider it as a scientific matter which must be treated by specialists. A new approach is also appearing : environment considered as a public matter, on which everybody can give its opinion and participate. The museum becomes therefore an open and public place, where every one can debate and discuss on science. We propose to think about the possibility to provocate this debate and discussion through the objects and the collections. Key-words : environment, debate, discussion, public place.