A large experimental complex built in the late 1980's to explore the possibility of living outside of the earth --biosphere 1--should the earth become uninhabitable. It is part research facility, part tourist attraction.
The primary structure consists of a large, mostly glass faced building, enclosing over three acres of land surface. Within this sealed enclosure, five of the earth's biotic zones are represented in condensed form: the rain forest, desert, Savannah, swamp and ocean. In addition there is an intensive agricultural area and a "micro city." Biosphere gained notoriety when, in 1991, eight "biospherians" entered the structure to begin the project's first major experiment: to farm and live in the totally sealed-off, self-contained world for two years. No material was supposed to pass into or out of the facility during that time. During the course of the experiment, however, oxygen levels dropped, and carbon dioxide levels rose to dangerous levels. Some biospherians became sick and spent time outside the structure. Ants from the rainforest invaded the desert, and the one million gallon ocean, complete with a coral reef uprooted from the Yucatan, clouded over into an opaque algael soup. Eventually the owner and original investor, Texas oil billionaire Edward Bass, gained control and entered into an agreement with New York's Columbia University, to restore "real" science to the $200 million plus project. Columbia took over in January of 1996, with a research agenda that mostly explores the effects of a high carbon dioxide atmosphere on plant development.