Abstract
More ambitious conservation efforts are needed to stop the global degradation of ecosystems and the extinction of the species that comprise them. Here, we estimate the minimum amount of land needed to secure known important sites for biodiversity, Earth’s remaining wilderness, and the optimal locations for adequate representation of terrestrial species distributions and ecoregions. We discover that at least 64 million km2 (43.6% of Earth’s terrestrial area) requires conservation attention either through site-scale interventions (e.g. protected areas) or landscape-scale responses (e.g. land-use policies). Spatially explicit land-use scenarios show that 1.2 million km2 of land requiring conservation attention is projected to be lost to intensive human land-use by 2030 and therefore requires immediate protection. Nations, local communities and industry are urged to implement the actions necessary to safeguard the land areas critical for conserving biodiversity.