The Earth appears to be at the beginning of sixth massive species extinction. This paper balances a review of the forces threatening species survival with a comprehensive scan of factors that could act as counterweights. These factors could lead to four types of evolution—cultural, regulatory,...

This paper presents a scenario depicting life in the United States in the year 2050. The scenario is designed to achieve energy sustainability: fossil fuels and corn ethanol have been replaced by other sustainable and inexhaustible energy sources. The scenario describes the disappearance of the...