Ecologists Eric R. Pianka (University of Texas) and Laurie J. Vitt (University of Oklahoma) provide a scientific summary of the overpopulation crisis facing humanity and itemize its many consequences, including climate change (global warming), conservation biology, economic systems, energy and resource shortages, human instincts, immigration conflicts, politics, pollution, poverty, technological problems, and solutions needed. Their underlying thesis is that denial and delusion work synergistically to undermine our ability to confront these serious issues, and unless we undertake proactive measures now, overpopulation and its impact on resource competition and climate change will ultimately lead to the collapse of civilization.