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Biosphere 2

Posted on 2015.09.14 at 13:21
Current Location: Cambridge, MA
Biosphere 2 was built as part of the space program.

There are a lot of science experiments going on out there in the world, but not so many engineering experiments, at least not many bigger than what can be done by one or two people in a suburban garage. What I mean by experiment is a carefully controlled endeavor designed to answer a question. In the case of Biosphere 2, the question was "Can we, using the knowledge we have now, in the 1980s, build human habitats that can be placed in orbit that will be self-sustaining, with inputs from Biosphere 1 (a.k.a. Earth) no more than once every two years?" The obvious way to answer the question was to build such a habitat, seal it off from the rest of the ecosystem, and try it out.

By late summer of 1991, it was ready: a sealable environment covering a little over 3 acres of sagebrush just north of Tucson, AZ, containing a desert, a rain forest, a savanna, a 700,000-gallon ocean with machinery underneath it to create tide-like movement, adjacent areas of both swamp and marsh, farmland and housing for the eight human researchers who would be sealed inside, vast amounts of sensors for keeping track of how the various parts of the habitat were doing, laboratory space, computers and the infrastructure for keeping it all going. On September 26th of that year, the eight-member crew was sealed inside.

All sorts of things went wrong. A species of ant native to the area, that was not supposed to be part of the sealed ecosystem, stowed away and ended up killing the pollinators, so the humans had to do all the pollinating by hand. Oxygen levels, originally set at roughly 21% of total air composition (typical at sea level) shrank to a little over 14% (typical of 13,000 feet) by the 16-month mark. (There were multiple reasons for that, one of which was not figured out until after it was all over.) It might have shrunk further if the outside support team hadn't breached the seal to inject some more. Certain rain forest trees became very weak as they grew because they didn't have wind stimulating them to produce stronger trunks. Most of the wild vertebrates died while the cockroaches multiplied out of control. And on and on like that. Some people thought this meant that the Biosphere 2 experiment was a failure, but it succeeded in the sense that it did answer the question it was designed to answer -- with a resounding "No."

A reboot was attempted in 1994, but this one really did fail due to human factors that included the sponsoring organization being dissolved. The facility changed hands several times, finally being acquired in 2007 by the University of Arizona, which has been using it for biology research and education ever since. It turns out that a series of sealable biomes like this is excellent for testing predictions related to climate change. For instance, there have been predictions of a drought in the Amazon rain forest. No one knew what that would look like in terms of its effect on particular species, so when I was there, the sprinklers in the rainforest biome had been turned off to see what would happen. Previously, they'd tried leaving the sprinklers on but increasing carbon levels in the atmosphere to see how much carbon the rainforest would absorb. The answer turned out to be: a lot, but not an infinite amount. The scientists who analyzed the data and then extrapolated it to Biosphere 1 concluded that the real Amazon rainforest is, indeed, absorbing carbon, moderating the effects of the massive amounts of carbon that worldwide civilization is putting out, but the effect will top out around 2050.

(About the time I die, I couldn't help thinking. This incarnation was right in the sweet spot. But of course that's what the Baby Boom was all about. Everybody wanted to live in this time slot right here, this brief golden age of prosperity, individual freedom and more knowledge about the physical world than humans have ever had. Now the birth rate is falling because applications are down.)

This was during the guided tour. A group of around twenty of us tourists was walked through the doors that looked exactly like spacecraft doors (for the obvious reason that they were designed to do what spacecraft doors do, i.e., seal off the inside from the outside as completely as humanly possible) into the various greenhouses and infrastructure by a chatty and informative guide. The greenhouses were bigger and more ambitious versions of those that house the tropical sections of public botanical gardens in those temperate-climate cities lucky enough to have such things. The machine rooms were like machine rooms everywhere. The ocean is not that big on the surface. The designers went for depth rather than an oceanic aesthetic, so the thing looked, from above, like a low-budget tropical island movie set. What impressed me the most were the lungs.

Air pressure here on Biosphere 1 rises during the day and falls at night. Earth life forms such as humans are so well adapted to this cycle that we generally don't notice. The designers of Biosphere 2 noticed, though, and became concerned that the pressure change would pop windows out of their frames. So they gave Biosphere 2 a pair of, basically, giant rubber dome-shaped bladders, each a hundred feet in diameter, that would inflate and deflate with the cycle, keeping pressure inside equal to pressure outside without any actual exchange of air. They're kind of obsolete now that the facility is no longer sealed, but they are echoey, magnificent and strange. Our guide led us into one, then worked the controls, raising it a bit, then lowering it back down. We were suitably impressed.

Then she turned us loose to wander around on our own, finding the undersea viewing chambers if we so desired, observing the interesting mineral samples and sculptures dotted around the grounds, and seeing what the place looks like from the outside. I did. I was trapped under a porch by pounding rain for a while. (The desert ecosystem gets an average of five inches of rain a year and may get it all in one storm.) I enjoyed the lightning, but by the time I got back to the reception area, it was empty and, technically, closed. I had been planning to get a meal in the cafeteria and spend some time (money) in the gift shop as well, but it turns out that, when our tour (the last of the day) left, so did the staff.

But nobody had locked up, so I checked it out. Very disappointing. That reception area was a great opportunity to do some real biology and ecology education, but it was wasted on tacky historic pulp science fiction stuff. The people at Biosphere 2 are scientists first, science educators second, and it shows.

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