Saturday, March 27, 2010

The slow march towards assigning value to ecosystems

In 1991, eight scientists entered a sealed, glass-enclosed, 3.15-acre structure near Oracle, Arizona, where they remained for two years. Inside was a diversity of ecosystems, each built from scratch, including a desert, a tropical rainforest, a savanna, a wetland, a field for farming, and an ocean with a coral reef. The "bionauts" were accompanied into their habitat by insects, pollinators, fish, reptiles, and mammals that were selected to maintain ecosystem functions. They were to live entirely off the land inside the dome. All air, water, and nutrient recycling took place within the structure.
 

Biosphere 2 was the most ambitious project ever undertaken to study life within a closed system. Never before had so many living organisms been placed in a tightly sealed structure. Inside the dome, air quality steadily declined. While a rise in carbon dioxide was expected, scientists were surprised at the drop in oxygen levels. While the ecosystems maintained life and, in some cases, flourished, there were many ecological surprises. Cockroaches multiplied greatly but fortunately took on the role of de facto pollinators as many other insects died off. Of the original 25 small vertebrate species in the Biosphere 2 population, 19 became extinct. At the end of 17 months, because of the drops in oxygen levels, the humans were living in air whose composition was equivalent to a 17,500-foot altitude. The lesson for nonscientists is that it required $200 million and some of the best scientific minds in the world to construct a functioning ecosystem that had difficulty keeping eight people alive for 24 months. We are adding eight people to the planet every three seconds.

taken from Natural Capitalism by Hawken, Lovins, and Lovins (1993).