Biosphere 2 Lost 19 of 25 Animal Species as Oxygen Fell to 14.2%

1 articles · Updated · spacedaily.com · Aug 20

19 of 25 backboned animal species died out inside Biosphere 2, and all pollinating insects vanished during the two-year sealed experiment, forcing the eight-person crew to pollinate crops by hand.
Oxygen dropped from 20.9% to 14.2% over 16 months because soil microbes produced carbon dioxide faster than plants could recycle it, while concrete absorbed the gas and masked the imbalance.
Cockroaches, longhorn crazy ants and weedy vines thrived instead, benefiting from sealed conditions, weak food webs and their ability to survive without specialized ecological partners.
$150 million in construction and about $1 million a year in energy still failed to replicate ecosystem services that natural systems provide, a lesson that later helped shift the Arizona facility into an open research lab.