Protected areas: a prism for a changing world.

The centrality of protected areas in biodiversity conservation has not changed over the past three decades, but we now know that biodiversity conservation represents a much more complex and dynamic picture than was once thought. In contrast to the earlier primarily aesthetic motivation (and still valid in its own right), the role of protected areas in biodiversity conservation is now widely accepted. Internationally, their importance has been recognized by the Convention on Biological Diversity and by the creation of intergovernmental funding agencies such as the Global Environmental Facility. As I discuss here, the rate of creation of new protected areas has increased rapidly to meet the need for a protected representative set of the ecosystems of the world. But that is only the start of the task.