The physical geography of the nineteenth century emphasised interlinkages between the physical environment and human society. During the twentieth century, the pressures toward specialisation have produced the four disciplines of biogeography, climatology, geomorphology and hydrology which have their own, independent integrity and physical geography has suffered some attrition as a unified field of geography. This book, and indeed the whole series, adopts global environmental change and its repercussions for society, as the coherent integrating theme to reinvigorate the physical geography of the twenty-first century. It looks at environmental systems and impacts, integrating opportunities and challenges in the field. Understanding Global Environmental Change (UGEC): Themes in Physical Geography. Physical Geography and Global Environmental Change is the first text to be published within this series, designed to meet the need for shorter, inexpensive and more sharply focused books suitable for use within physical geography.