Bud and Doyle are two losers who are doing nothing with their lives. Both of their girlfriends are actively involved in saving the environment, but the two friends couldn't care less about saving the Earth. One day, when a group of scientists begin a mission to live inside a "Bio-Dome" for a year without outside contact, Bud and Doyle mistakenly become part of the project themselves.
In a future Earth barren of all flora and fauna, the planet's ecosystems exist only in large pods attached to spacecraft. When word comes in that the pods are to be jettisoned into space and destroyed so that the spacecraft can be reused for commercial purposes, most of the crew of the Valley Forge rejoice at the prospect of going home. Not so for botanist Freeman Lowell who loves the forest and its creatures, so decides to take matters into his own hands to protect what he loves.