Antarctic environmental challenges in a global context

In the nearly two centuries that have passed since the discovery of the Antarctic continent, global environments have changed dramatically. Biomes that were originally described on the basis of the species and assemblages naturally found there have now given way to those more readily recognized by the extent and nature of human influence. Biodiversity is under considerable threat. Habitat alteration, biological invasions, over exploitation,pollution and climate change are having large impacts. Although various international policy instruments have been adopted in an attempt to stem this tide of change (such as the Convention on Biological Diversity), their success has been limited. Despite the positive role of protected areas, biodiversity continues to decline. Habitat transformation is abated only to the extent that some habitats can no longer be much transformed because so little of them now exist.