[en] The first difficulty to get over in the international negotiation on the climatic change, has been and still remain the distribution of the efforts and the research of the equity in the objective determination. This paper aims to show that facing the different interests of each countries, a single rule of differentiation is not possible. The first part is a review of the different charts of the objectives differentiation discussed or proposed in the international negotiation process on the greenhouse effect. It aims to find a bond between the the charts and the equity. The second part proposes the quantification of a scenario of the emission licenses attribution for 2030 for all the world countries. (A.L.B.)