“Nature’s dependent variables within the earth system, including climate change, stratospheric ozone depletion, oceanic acidification, global eutrophication in nitrogen and phosphorus cycles, overexploitation of land and freshwater, chemical pollution, atmospheric aerosol loading, are under increasing scrutiny. The crucial one, in which all the others are compounded, is the incipient decline in biodiversity. Will we enter an Anthropocene epoch, or is the entire Cenozoic era – time of the mammals – coming to an end? That is how the question stands.” [From Preface]