Restoring Mars to habitable conditions: Can we? Should we? Will we?

Two scenarios are presented for terraforming Mars into a habitable state: one state suitable for plants and another with an atmosphere suitable for human habitation. Studies of Mars indicate enough necessary elements to provide raw materials. Transformation would take two stages: the first to warm the planet and release carbon dioxide, the second to convert carbon dioxide into oxygen and build up nitrogen in the atmosphere. Present knowledge indicates that it is possible to transform Mars into a habitable state. Environmental ethical concerns are reviewed from three axioms: human intervention is ultimately harmful to the environment, stewardship, and intrinsic worth.