This book examines the differences and similarities in the earth system components - the ocean, atmosphere, and the land - between western portions of the northern and southern Western Hemispheres, past, present, and projected. The book carefully examines the physical and biological patterns and responses of given biomes, or ecological communities in the two regions. Special emphasis is placed on the relationship of physicial and biotic systems to biogeochemistry and the evolving biota patterns of land margins and surfaces. The text concludes with an assessment of the direct impact on humans on these biomes, giving full consideration to the land-use drivers of global change.