Biosphere 2

The Biosphere 2 project attempted to make a materially isolated system in which the animals, including people, produce carbon dioxide and consume oxygen; the plants produce oxygen and consume carbon dioxide; and the entire set of interactions between animals, plants, and microbes recycles the materials necessary to life. It enclosed more than 3 acres. The originally planned recycling failed and many species of animals became extinct in the enclosure while other animals and plants wildly increased in number.

It seems that the main original difficulty was underestimating the problem of establishing a stable recycling system of plants and animals in imitation of the wild recycling system on Earth. More regular study of the various animals and plants to be put into such a system is required to learn all of their specific needs and products. Proper research should be done in smaller scale enclosures with regular records being kept. Just how difficult it is produce a closed recycling life support system as originally planned for Biosphere 2 will be learned when the goal is accomplished.