The five papers take quite different approaches to conservation at a global scale.1 Sala et al. [5] focus on projecting the status of biodiversity in 2100 on the basis trends that were detectable at the time the paper was written. Myers et al. [3] focus on identifying regions of the world where it may be possible to get the most bang for your conservation buck because of the large number of species there. Kareiva and Marvier [2] take issue with the hotspot approach as being to narrowly focused on species numbers and ignoring other important conservation objectives. Hoekstra et al. [1] use the Olson et al. [4] classification of terrestrial ecoregions of the world to identify biomes that are the most in need of conservation attention. Because each approach is a little different from the others, I'll summarize each of them before posing questions for discussion.