Pandemics, global warming, food security, ageing, depletion of certain raw materials... our economies are faced with global problems, calling for long term actions and raising intergenerational issues. To guide economic policies, it is therefore essential to have a sound framework for reflection. The MaGE (Macroeconometrics of the Global Economy) model, developed by CEPII, makes it possible to draw the fundamental trends of the world economy in the long term, up to 2050. On the backdrop of the continued pace of economic and demographic growth and technological progress, energy consumption is expected to double by 2050, despite efforts to improve energy efficiency. Ambitious policies to decarbonize our economies will be necessary to make these prospects for economic growth sustainable.