More than 20 years after the Brundtland report, the human development debate is weakly present in Ecological Economics and the environmental debate is weakly present in discussions around Sen's capability approach. In this paper, we try to build a bridge between the two by crossing Sen's capability approach with the Critical Natural Capital (CNC) theory. fisrt we demonstrate How to make Sen capability approach more comprehensive to the environment. In a second part, we start from the side of the EE and CNC theory and try to show how Sen's capability approach could light the issue of the definition of what is critical and for whom . We assume that crossing Sen's capability approach and the CNC theory would provide integrated theoretical foundations to foster Sustainable Human Development Research.