Biosphere 2, 1991.

FOREWORD TO SECOND EDITION by Sylvia A. Earle

      “YES!” WAS MY IMMEDIATE RESPONSE to the invitation to be present and speak at the opening of Biosphere 2 after eight intrepid explorers had lived and worked within the confines of their glass-enclosed microcosm for two full years, September 26, 1991-September 26, 1993. Like many others, I had followed with fascinated interest what seemed to be an Arthur C. Clarke-like futuristic fantasy, but in fact involved real people living an otherworldly experience in real time. As a witness, as a scientist, and as one who had been part of a space simulation project more than twenty years earlier, I was intrigued and sometimes incredulous as the audacity of the Biosphere 2 vision became a successful reality. The Biosphere 2 team quickly demonstrated that one doesn’t have to travel far to discover extraordinary new horizons.

      Like Abigail (Gaie) Alling, co-author of this book, I am a marine biologist who literally becomes immersed in my research. I could not resist the opportunity in 1970 to live underwater for two weeks, leading a team of five women scientists and engineers during the NASA-US Navy-Smithsonian Institution-US Department of the Interior-sponsored Tektite II Project. Like the biospherians, those of us who lived as aquanauts isolated from direct contact with people on the outside were subjected to intense scrutiny by physicians, psychologists, and the public who were hoping to learn from the behavior of the ten teams who participated in the project, insights applicable to living in space and potentially, on the moon or other planets.

      And, like the biospherians, we were keenly aware of the limits of our life support systems, from food and freshwater supply, to temperature, pressure, and especially the levels of oxygen and carbon dioxide in the air. But unlike them, we did not face the challenge of spending two years essentially self-contained, relying on living systems that had to be assiduously cared for to produce food and oxygen, absorb carbon dioxide, recycle wastes and otherwise provide for aesthetic and psychologically pleasing surroundings.

      What I find most remarkable is that the Biosphere 2 system worked as well and lasted as long as it did before an outside source of supplemental oxygen was required. After all, it took four and a half billion years to develop Biosphere 1, Earth, as we know it: a living planet that is home to millions of species that together, maintain sufficiently stable chemistry and temperature to persist as a place habitable for life in an otherwise extremely hostile universe.

      Most surprising, Biosphere 2 worked despite a distinctly terrestrial bias, while Earth is literally a “water planet.” All life requires water and ninety-seven percent of Earth’s water is ocean. It is also where about ninety-seven percent of life exists and where most of the oxygen in the atmosphere is generated, mostly by photosynthetic plankton. The essential role of microbial life in shaping the chemistry of individual organisms, of ecosystems, and ultimately of the entire planet has only recently begun to come into focus. The ocean hosts a bountiful microbial minestrone of bacteria, Archaea, and viruses that underpin the rest of life as we know it. Climate, weather, temperature, and planetary chemistry are largely governed by the living sea.

      Though small in size, and relatively limited in diversity compared to natural coral reef systems, Biosphere 2’s ocean appeared to be in good health when I was privileged to dive into it, accompanying Gaie on a tour the day that the team emerged. I was delighted to see not only healthy, living corals but also a number of young coral colonies, evidence that spawning, settling, and growth had taken place in their cocooned world. A common species of brown algae, Dictyota, was abundant, and Gaie said she had to periodically “weed” the reef to prevent damaging overgrowth of the corals. It was exciting to discover a relatively rare kind of green algae thriving amid various other algal species, invertebrates, and fish. I also noted when I slipped underwater, that a number of confused cockroaches