[en] The long term future of the planet's climate will depend of the policies implemented in the next decades. While economic development in the last two centuries has been based on an intensive use of fossil energy resources, the major challenge for the 21. century is the transition towards low carbon energy systems. This will impose drastic changes in the dynamics of some fundamentals variables of energy development in every region, in particular the energy intensity of GDP and the carbon intensity of the energy mix. The accumulation of greenhouse gas in the atmosphere and consequently the climate for the future generations will directly depend of the capability of the international community to implement the required changes in economic development patterns. (authors)