The growth of world demography and the acceleration of the development processes of the most economically backwards States will create a disquieting progression in the emission of greenhouse gas. This trend shall have inevitable consequences on our planet’s temperature levels : a significant increase is to be expected for the next century. The risks created by this evolution for international security, are multiple and heterogeneous. This climatic warming will be different in each area, thus engendering vast discrepancies that will limit the possibilities of international cooperation in this field. Two types of threats to international security can be foretold : the first is directly related to climatic changes (economic costs related to environmental damage); the second is indirect, yet more dangerous, since it is related to the intern fragilization of the harmed States and to the chances that this instability should contaminate other States. Thus, preventive action proves to be necessary, on the causes of this phenomenon, as well as on its consequences. – Summary AFRI-2005