An important approach to conservation of species or ecosystems is to assess their risk of extinction. This is most well known in its application to species with IUCN developing the red list of species which categorises risk to species from extinct, critically endangered to a status of least concern. There is a growing body of expertise and knowledge which is applying this approach to ecosystems, recognising the opportunity to conserve broad regions of the environment. Resulting status of species and ecosystems can become a focus for management and policy.