How do people value nature, and how do they reason morally about environmental degradation? Do children have a deep connection to the natural world that gets severed by modern society? Or do such connections emerge, if at all, later in life, with increased cognitive and moral maturity? How does culture affect environmental commitments and sensibilities? Are there universal features in the human relationship with nature? Toward answering these questions, I draw from three studies on childrenÍs environmental moral reasoning and values. In one study, my colleagues and I interviewed children in an inner-city black community in Houston, Texas. In another study, we interviewed children in the Brazilian Amazon. In a more recent study, we interviewed children, adolescents, and young adults in Lisbon, Portugal. I shall hope to make compelling the importance of a structural-developmental psychological account of the human relationship with nature. Finally, based on this account, I will articulate what may be one of the most pressing and unrecognized problems of our age -- the problem of environmental generational amnesia.