Biosphere 2: A man-made Earth which trapped humans for 2 years

In the Arizona desert , far from cities and farmland , stands a massive glass structure that once hosted one of the world’s most ambitious scientific experiments known as Biosphere 2, the facility was built to answer a bold question: Can humans survive in a completely closed environment with no outside help ?​

Biosphere 2 was designed as a self-contained system that mimicked Earth’s natural processes. Covering 3.14 acres and enclosed by more than seven million cubic feet of sealed glass, the structure was isolated from the outside world by a welded stainless-steel liner. No air , food or water could enter or leave once the system was sealed.​

Inside the structure, scientists created several interconnected biomes, including a tropical rainforest,an ocean with coral reefs, a mangrove wetland, savana grassland, and a fog desert. Each ecosystem  depends on the others, meaning even small changes in one area could affect the entire system. Unlike a natural ecosystem , every variable inside Biosphere 2 - temperature, humidity, and gas levels could be carefully monitored and adjusted.

The most famous phase of the project began in 1991, when eight people were sealed inside the structure for two full years. They grew their own food, recycled water, and lived entirely within the closed system. Outside supplies were strictly forbidden. The experiment was difficult. Oxygen levels dropped, food production fell short of expectations, and tensions arose among the participants. Yet the mission revealed how fragile and complex closed ecosystems truly are, and how little room for error exists when life depends on a sealed system.​

Over time, the purpose of Biosphere 2 evolved. Originally intended to explore space-colony survival, it later became a centre for Earth-focused environmental research. Managed by universities and supported by public and private funding, the site now hosts studies on soil formation, water cycles, erosion, and climate change.