[en] This note aims to explain the evolution of the intensity of the the developed economies of the greenhouse gases emission. This study concerns only the countries called industrialized without the developing countries and those of the old east soviet bloc. In the first part the authors aim to know if the carbon intensity evolution of the economies go with convergence or divergence phenomena. The second part is more devoted to the impacts of the energetic choices on the adopted policies of the countries. Finally a particular attention is given to the characteristics of the european union countries which present a unique policy among the developed countries. (A.L.B.)