Nearly 15 years after the first managerial team of Biosphere 2 was ordered out by federal marshals, scientists yearn for a way to fulfill the true promise of Earth-in-a-bubble experiments.
"We need to do this again, and better," said Daniel Botkin a University of California, Santa Barbara naturalist who sat on Biosphere 2's original advisory committee. "We don't understand how ecosystems function, how life is sustained on the Earth.
The way you study any system is to take a part of it and try to understand the principles inside."
Researchers still work inside the $200 million, glass-and-steel complex, but with slightly less modest ambitions. The sphere's windows, once sealed tighter than the space shuttle, open to Arizona air. Most of the original biomes are a tourist attraction. Research focuses on plant function in an arid semi-desert environment, rather than the ecological dynamics of a miniature planet.
"The biosphere is hugely important. It can answer questions that are impossible to answer any other way. The problem is that building the biosphere today would be cost-prohibitive," said Joaquin Ruiz, dean of sciences at the University of Arizona, who in 2007 took over Biosphere 2's management.
Only one other biosphere, in Japan, has been built, making biospheres a tool essentially abandoned by science. This is a tragedy to researchers who think some questions are best explored in man-made environments big enough to capture some of Earth's ecological complexities, but small enough to host rigidly-measured experiments that couldn't be duplicated in nature.
To anyone familiar with Biosphere 2's controversial origins, that might seem an odd notion. Eight people sealed inside between 1991 and 1993 fought bitterly over the nature and direction of its research. The original Scientific Advisory Committee resigned en masse. Oxygen dropped to dangerous levels. Carbon dioxide levels skyrocketed. Biomes were overrun by an ant species that wasn't supposed to be there. Before Columbia University took over in 1995, Time Magazine concluded that "the two-year experiment in self-sufficiency is starting to look less like science and more like a $150 million stunt."
Some of those problems were inevitable and possibly instructive bugs in a system that was a giant beta test, with the alpha being Earth. Others reflected human flaws. But space-suited theatrics and Noah's ark overtones aside, Biosphere 2 was still the world's most ambitious test tube. Such tubes could still be valuable in an age of environmental sensors and satellite recordings, helping fill a research niche between small- and large-scale observations, generating hypotheses for field studies of climate change and other environmental vagaries.
"The large-scale closed systems that can be constructed in B2 allow carefully controlled physical experiments with actual environmental systems," said Larry Winter, deputy director of the National Center for Atmospheric Research and an advisor to its University of Arizona-run incarnation. "You can think of B2 as the ecoscience equivalent of a chem lab."
The original Biosphere 2 mission, though convoluted, did generate useful findings. Some were almost conceptual – that life inside the sphere changed in such unpredictable ways, and could be so profoundly affected by human activity, was a lesson unto itself. More tangibly, it produced a wealth of literature on how future biospheres might be constructed by space explorers and colonizers, who cannot expect to bring with them enough supplies for long-term survival.
Other research described carbon and oxygen cycles within the sphere, the physiology of plants in a high-CO2 environment, waste remediation and agricultural techniques. It wasn't a bad show for what was, in effect, a beta test focused less on academic research than the survival of its inhabitants.
When Columbia University's Lamont-Doherty Earth Observatory took over in 1995, they struggled to re-tool the sphere for more rigid ecosystem analyses. Some of the research focused on underpinnings of atmospheric processes, such as rates of gas exchange between soil and water.
"Just the fact that there was a building big enough and tall enough that rain could reach terminal velocity, and a big enough seawater space that you could study gas exchange" was unique, said John Dacey, a Woods Hole Oceanographic Institute biologist, of the Lamont-Doherty research.
Dacey was not involved in that work, but was invited to perform research at the sphere. He eventually declined, unable to create control conditions inside the biosphere that would allow for comparative research. But he said the facility could still be valuable for generating hypotheses about environmental effects.
The most striking example of this involved the acidifying effects of elevated atmospheric carbon dioxide on coral reefs in the sphere's ocean biome. In the years following Columbia's stewardship, ocean acidification has become one of the most troubling effects of climate change.
"Much of what is known about coral reefs and ocean acidification was originally discovered ... in the self-enclosed, supposedly self-sufficient world known as Biosphere 2," wrote Elizabeth Kolbert in the New Yorker in 2006.
The University of Arizona opened the windows, but Biosphere 2 remains useful. Researchers can still account for nearly every drop of water and watt of sunlight, track parts-per-billion flows of carbon and oxygen, and monitor every organism. Though it's too early to measure the value of this latest phase of research, a study published last week in the Proceedings of the National Academy of Sciences hints at its continuing utility.
Researchers transported 20 local pine trees into Biosphere 2, keeping half in standard temperatures and warming the others by 7 degrees Fahrenheit. When they reduced the trees' water, those in a warmed environment died rapidly. The resulting paper describes a damaging synergistic effect between drought and expected climate changes.
"Right now you have people doing experiments in really fancy pots, and people out in the field," said Ruiz. "The biosphere allows you to scale between those two sets of data."
The University of Arizona is also studying the hydrological effects of desert vegetation changes, and the rainforest dynamics of carbon, oxygen and vegetation in a variable-climate setting.
"It's absolutely required for the kind of issues we deal with in large-scale ecology," said Ruiz. "The only way ecologists are going to be able to deal with the complexity of systems is if they have large-scale systems in which they can control variables and see feedback loops."
Another important effect of Biosphere 2 is social, said Winters.
"The existence of the facility becomes a catalyst for inter-disciplinary teams to form, the kind of teams we need to investigate the coupled environmental systems that we understand so little and depend on so much," he said.
See Also:
- Biosphere 2 Not Such a Bust
- Wired 12.12: 10 Lessons from Biosphere 2
- Life Inside the Biosphere Bubble
- Biosphere Crew Hawks Pets with Space Pedigree
Images: University of Arizona
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