Every year, a forested area the size of Costa Rica vanishes from the Earth, along with all the dependent species that called it home. A portion of the blame falls to natural causes of deforestation, but millions of hectares yield to the ravages of human climate change and modern agriculture [source: U.N.].
The spaceship Valley Forge, however, might just help matters. Featured in the 1972 environmental sci-fi classic "Silent Running," this converted American Airlines freighter boasts an array of geodesic greenhouse domes, each devoted to a different terrestrial ecosystem and Joan Baez song. A fleet of these vessels keeps the dream of a green Earth alive near the orbit of Saturn, awaiting the day they can return home to revitalize a poisoned and barren world.
That is, assuming the powers on Earth don't decide to nuke the forests and return the ships to commercial service. Leave it to greedy corporations to outfit an environmental seed ship with atomic detonators.