The present global ecological crisis demands a critical reassessment. This book suggests that one valuable approach can be found in the well-known I=PAT formulation: that environmental impact (I) is a function of population (P), affluence (A), and technology (T). The contributors propose that IPAT can be assessed in light of the concept of sufficiency: the idea that limits, bounds, or “enoughness” are central to the discussion. What is ‘sufficiency’ in this context, in an era defined by ecological overshoot and growth-driven economic policies? How much is enough, and how much is too much? This volume breaks new ground by addressing all three of the IPAT factors in a forthright manner, in the light of sufficiency.