Widespread climate change challenges traditional notions that preserving specific chunks of land is an adequate way to protect endangered species. Commitment to particular places has taken conservation a long way, but it works only when the climate is relatively stable. When climate change rather than degraded habitat threatens a species' survival in a particular location, moving the species to new locales might become one way of preserving it. Some ecologists argue that such assisted migration is simply a way to mimic the natural process of dispersal: its adherents intend to transport species from places that have become uninhabitable through places that humans have made impassable. Although it has its risks, assisted migration may be a necessary step in the evolution of conservation.