The global debate around sustainability and development is gridlocked, whether it is the development of the post-Rio+20 SDG (sustainable development goals), the shaping of international development policy, or the design of stimulus for an economy marred by financial crisis. The debate boils down to the tension between recognizing planetary limits versus "the right to develop." Breaking or at least clarifying this gridlock would be the most transformational piece to add to the current debate. What are the choices? How much ecological debt can we accumulate before it is economically disadvantageous? Where are the synergies between poverty alleviation and recognizing resource limitations? What are the knowledge gaps in both the natural and social sciences for addressing this fundamental gridlock in the development debate?