Human overpopulation now threatens our very survival. The scientific evidence suggests that when women have access to contraception, choice and education, they reproduce later, have fewer children who have a chance for health, happiness, and well-being, and the women and children have the chance to be productive contributors to a healthy and just society. The issue of human overpopulation has led to deleterious depletion of natural resources and ecological process that allow for human life, this is predicted to overcome our abilities at technological solutions so social and psychological solutions are needed, and the most compassionate way forward. This will also require changing our economic models to something more like a steady state economy, finding creative strategies for caring for the elderly and other globally pressing issues. This makes this challenge truly cross disciplinary, cross sector and international. Interventions could be implemented and assessed within a decade, but further longitudinal assessments would be needed and desired. The solutions are already known in large part, the innovation would be grasping the human psychological barriers that have so far prevented us from creating a just and feasible human presence on our planet and designing and implementing the interventions.