Collapse: How Societies Choose to Fail or Succeed (titled Collapse: How Societies Choose to Fail or Survive for the British edition) is a 2005 book by academic and popular science author Jared Diamond, in which the author first defines collapse: "a drastic decrease in human population size and/or political/economic/social complexity, over a considerable area, for an extended time." He then reviews the causes of historical and pre-historical instances of societal collapse—particularly those involving significant influences from environmental changes, the effects of climate change, hostile neighbors, trade partners, and the society's response to the foregoing four challenges. It also considers why societies might not perceive a problem, might not decide to attempt a solution, and why an attempted solution might fail. While the bulk of the book is concerned with the demise of these historical civilizations, Diamond also argues that humanity collectively faces, on a much larger scale, many of the same issues, with possibly catastrophic near-future consequences to many of the world's populations. Synopsis In the prologue, Jared Diamond summarizes his methodology in one paragraph: Collapses of past societies Diamond identifies five factors that contribute to collapse: climate change, hostile neighbours, collapse of essential trading partners, environmental problems, and the society's response to the foregoing four factors. The root problem in all but one of Diamond's factors leading to collapse is overpopulation relative to the practicable (as opposed to the ideal theoretical) carrying capacity of the environment. One environmental problem not related to overpopulation is the harmful effect of accidental or intentional introduction of non-native species to a region. Diamond also writes about cultural factors (values), such as the apparent reluctance of the Greenland Norse to eat fish. Diamond also states that "it would be absurd to claim that environmental damage must be a major factor in all collapses: the collapse of the Soviet Union is a modern counter-example, and the destruction of Carthage by Rome in 146 BC is an ancient one. It's obviously true that military or economic factors alone may suffice". Modern societies He also lists twelve environmental problems facing humankind today. The first eight have historically contributed to the collapse of past societies: Deforestation and habitat destruction Soil problems (erosion, salinization, and soil fertility losses) Water management problems Overhunting Overfishing Effects of introduced species on native species Overpopulation Increased per-capita impact of people Further, he says four new factors may contribute to the weakening and collapse