I choose to speak about a happy 2040 and not about the one I fear. If we have progressed on a path of sustainable development, it is due to far better connections between top down and bottom up processes. So far, these connections are very scarce. Decision makers at the international levels are not aware of the most pressing challenges at the local levels and vice-versa. This creates at all levels the wrong perceptions linked to "complotism" in general. The main cause of this dialogues de sourds between local and global levels of policy-making is the hierarchy between economic, social and environmental goals, actors and processes. The borders between economics, social sciences and environmental sciences and the lack of transdisciplinary culture are largely responsible for this lack of mutual understanding and consideration. My hope is that in 2040 the borders between these political and scientific silos will be replaced by an overall focus on the difference between bottom up (cacophony of actors) and top down (hierarchy of institutions with economic ones at the top) actions and the elaboration of instruments which are needed to interconnect them.