The world’s ecological crisis gives a new urgency to the dialogue between science and religion. Unless people of different worldviews (religious or secular) can arrive at a shared concern for the natural world, the ecological integrity of our planet is in danger of being completely undermined. In response to the world’s ecological crisis, the governments of the world have united behind a common vision for the future: the vision of a sustainable society or a sustainable development, and a policy program for its implementation in the twenty-first century. The program, known as Agenda 21, calls for development that meets the needs of the present without compromising the ability of future generations to meet their own needs. To obtain this goal, we have to ensure that natural resources are not used inefficiently or shortsightedly. The carrying capacity of the planet’s ecosystems must not be jeopardized today or in the future. Many are convinced that to achieve this, we need a new ethic, one of sustainable development. What is the content of this new ethic? And what roles do science and religion play in it?