01:38
The Delicate Balance, Part 2: Species Loss
Humans have altered the habitats of life forms from microscopic to whale-sized. General estimates of species loss is tens of thousands of species per year.
07:57
Ecology: Biosphere 2: A Laboratory for Studying the Future
While Biosphere 2's efforts to duplicate earth's complex ecological systems were unattainable, this scaled-down model is ideal for studying the effects of man on ecosystems. It is possible, for instance, to elevate carbon dioxide to the levels predi...