In a world of rapid change and political confrontation, what are the implications of 'forced' migrations and the flight from degraded ecosystems? Environmental and, in many cases, population pressures combine to make many regions of the planet both unproductive and uninhabitable, and the total number of conventional and environmental refugees is becoming a global problem. This chapter discusses the challenge of environmental refugees in the context of a typology that differentiates between 1) eco-metabolism or ecosystemic changes, including land degradation, soil exhaustion, desertification, and sea-level rise; 2) human-induced disasters, including industrial disasters, deforestation, deterioration of major watersheds, and effects of public projects; 3) eco-political upheavals, including revolutions, collapse of regimes, 'Balkanization', and shifting or fading frontiers; and 4) socio-economic dislocations, including collapse of expectations, shifts in the international economy, and inappropriate development strategies. Responses to this challenge involve integrated, proactive approaches, the promotion of sustainable development, guaranteeing security, and stabilizing the ecosystem to avoid further environmental deterioration.