Although governments have deployed an array of environmental protection laws, our planet continues to experience unprecedented environmental “crises,” including climate change, resource depletion, species extinction, ecosystem damage, and toxic air-water-land pollution. Despite universal acknowledgment and recognition of these serious environmental issues, and despite a growing list of laws designed to address these issues, the reality is that these adverse Earth-based environmental changes continue, and may even be worsening. Environmental protection laws have often failed because they usually include certain problematic characteristics: they are anthropocentric, in that their goal is to protect and benefit humans, not the environment in which humans live; they assume human superiority and exceptionalism to nature and natural processes; they are based on the notion that humans are separate from nature; they presume that humans are not ultimately limited by planetary boundaries, because they are superior and somehow insulated from nature. Moreover, these laws use an unrealistic model for humans—where human motivations are consistent with the homo economicus model used by traditional resource economists—the always rational, self-interested economic person motivated by negative laws, which tell humans what not to do. They also rely on an unrealistic model for nature, where nature is perceived too simply, as a closely integrated, self-regulating, complex system that works best when left alone by humans. This view is not consistent with the science of how nature really works, which is as complex adaptive systems. This Article reviews how these assumptions and models have largely influenced legal resources and environmental decision-making over four distinct eras during the past three hundred years—the Use, Conservation, Preservation, and Protection Eras. For environmental laws to work in a new, more Ecocentric Era, laws would be built on three foundations. First, environmental laws would not continue to rely exclusively on the assumptions and models used in previous eras, but instead would reflect the reality of how humans behave and nature works. Second, these laws would impose an affirmative duty on humans to make choices consistent with ecological integrity and planetary boundaries—in other words, rather than telling humans what not to do, laws should tell or encourage humans what to do. And third, rather than rely on rules that seek to prevent humans from creating negative environmental externalities, these new laws would create incentives for humans to create positive ecocentric externalities.