BIOSPHERE 2. Constructed of steel-framed glass, this 1.28-hectare structure near Oracle, Arizona, is intended to replicate ecological environments on earth (that is, Biosphere 1) under closed conditions. In addition to agricultural and living areas for its human occupants, Bio-sphere 2 houses tropical rain forest, desert, savannah, and cloud forest ecosystems as well as a coral reef within a miniature ocean. The original purpose of Biosphere 2 was to provide baseline data for designing structures for long-term habitation by humans in space. The underlying philosophy was that biological systems were self-organizing and self-regulating on a global scale, a notion that met with considerable skepticism in the scientific community. In an exercise described by some as more showmanship than science, four men and four women sealed themselves within Biosphere 2 in September 1991. Over a two-year period, oxygen was depleted and had to be replenished, and failed crops resulted in the restriction of the occupants' diets to 1,750 calories per day. Supporters maintained that results of serious scientific interest were obtained, including data on nutrient dynamics and waste-recycling technology. Critics pointed out that Biosphere 2 was privately funded (by the Texas oil billionaire and self-described "ecopreneur" Edward Bass), freeing it from the strict, objective evaluation required of publicly funded research. A second, seven-person team inhabited Bio-sphere 2 between March and September of 1994. During that period, in an effort to rehabilitate the project's credibility, a new administration established a consortium to conduct future research with scientists from Columbia University's Lamont-Doherty Earth Observatory.
Vergano, Dan. "Brave New World of Biosphere 2." Science News 150, no. 20 (16 November 1996): 312–313.