This volume lays the physical and conceptual groundwork for the "Pacific World" series, exploring both the constraints imposed and the opportunities offered to humanity by the physical environment of the Pacific region. Organized from the perspectives of "Big History" and macro-geography, the volume presents a series of major studies and surveys by authors from a range of disciplines. Opening with perspectives on the ocean, the purview expands to include geology, oceanography, climatology and biogeography. In closing, the volume examines questions of human settlement, diffusion, and trans-Pacific contacts.