The goals for a transition toward sustainability, as we set them out in Chapter 1, are to meet human needs over the next two generations while reducing hunger and poverty and preserving our environmental life support systems. The activities to approach this goal can only move ahead within the constraints set by resources and the environment. Many people have argued that, unless we make dramatic changes in our human enterprises, the development needed to meet future human needs risks damaging the life-support capabilities of the earth—which in turn would of course prevent society from meeting its goals. In this chapter, we therefore ask two related questions:
• What are the greatest threats that humanity will encounter as it attempts to navigate the transition to sustainability?
• What are the most promising opportunities for avoiding or circumventing these threats on the path to sustainability