The Ambitious Dream of Creating a Second Earth

In 1987, Discover magazine heralded what it called “the most exciting scientific project since President Kennedy launched the moon program.” This was Biosphere 2—a daring experiment to build a fully enclosed, self-sustaining replica of Earth’s ecosystems. The name itself revealed its grand ambition: if Earth was “Biosphere 1,” this artificial world would be its successor.

Conceived in 1982 during a meeting of environmentalists and leading scientists in rural France, the project aimed to address existential questions. Could humanity create a habitable environment for Mars colonization? Would it serve as a refuge in a nuclear war? Above all, it sought to test whether humans could engineer a functioning biosphere detached from Earth. Funded primarily by Texas billionaire Ed Bass, the $200 million structure (six times over budget) sprawled across 1.3 hectares in Arizona’s desert, housing five miniature biomes: rainforest, savanna, marsh, desert, and even a wave-generating ocean.

The Experiment Begins: Triumph Turns to Trouble

On September 26, 1991, eight researchers—four men and four women—entered Biosphere 2 amid global fanfare. Their mission: survive for two years without external aid, farming their own food and recycling air and water. The sealed glass-and-steel enclosure, equipped with “lungs” to regulate air pressure, was stocked with 3,000 species of plants and animals.

Disaster struck almost immediately. Ten days in, crewmember Jane Poynter lost part of a finger in a threshing accident, forcing a brief evacuation—violating the “no exit” rule. Far worse, oxygen levels began plummeting unexpectedly. By 1993, concentrations dropped to 14% (equivalent to Everest’s summit), causing chronic fatigue. Scientists later traced the crisis to unexpected carbon dioxide absorption by concrete and microbial activity in soil. Meanwhile, cockroaches and ants overran living spaces, pollinators died off, and acidic seawater killed marine life.

Societal Collapse in Miniature

Beyond ecological failures, Biosphere 2 revealed startling human dynamics. The isolated group fractured into rival factions that refused to cooperate—a cautionary tale for space colonization. Yet amid the strife, two romantic partnerships emerged, inspiring reality TV shows like Big Brother. By June 1993, seven of the original eight quit early, exhausted. A second crew in 1994 aborted their mission within months due to nitrous oxide poisoning.

Legacy: From “Disaster” to Scientific Insight

Initially dismissed as a costly folly, Biosphere 2 ultimately yielded invaluable lessons. It exposed gaps in understanding closed ecosystems—particularly how unseen variables (like concrete chemistry) disrupt equilibrium. Columbia University repurposed it for climate research, publishing landmark studies on CO₂’s marine impacts. Today, managed by the University of Arizona, it hosts ecological experiments and tours, sustained by Bass’s enduring funding.

The project’s true legacy lies in humility. As astrophysicist Neil deGrasse Tyson noted, “Biosphere 2 taught us that Earth, evolved over billions of years, is far more complex than we imagined.” Its failures underscore why—for now—there’s no substitute for Biosphere 1.