Science , Policy , and Environment in the 21 st Century

Humanity in the twenty-first century faces a new generation of environmental challenges. These differ significantly from past environmental problems that were familiar local accompaniments to the industrialization process. In the mid-1970s, the first truly global threat to the planet – depletion of the stratospheric protective ozone layer – was theorized, derided, hotly debated, and ultimately proven true, later earning for its discoverers the Nobel Prize. In the years following, scientists across a broad range of disciplines began to sound alarms about other portentous environmental changes caused by human activities: the greenhouse effect and climate change, the mass extinction of species and loss of biological diversity, the worldwide destruction of forests and habitat, the diffusion of persistent organic pollutants, the spread of desertification and land erosion, the pollution of oceans and coastal waters, and the growing pressures on fresh water.