The paper "Conservation Imperatives: securing the last unprotected terrestrial sites harboring irreplaceable biodiversity" by Dinerstein et al. proposes a strategic approach to protect areas that are crucial for preserving rare and threatened species. The authors define "Conservation Imperatives" as 16,825 unprotected sites spanning approximately 164 million hectares of the terrestrial realm, which harbor rare and threatened species. They estimate that protecting these sites would cost around US$169 billion. The study highlights that 38% of these sites are either adjacent to or within 2.5 km of existing protected areas, potentially reducing land acquisition and management costs. The authors emphasize the urgency of prioritizing these sites for conservation action over the next five years as part of a broader strategy to expand the global protected area network. They also discuss the need for multiple approaches, including land purchase, community reserves, and government re-designations, to meet long-term protection goals. The paper provides a detailed methodology for identifying and prioritizing these sites, including species rarity layer mapping, fractional land cover analysis, and cost assessment. The results show that only 7% of new protected areas created between 2018 and 2023 overlap with unprotected species rarity sites, indicating a need for more strategic planning. The authors conclude that protecting these sites is both affordable and achievable, and they offer a starting point for guiding biodiversity protection commitments from various sectors.The paper "Conservation Imperatives: securing the last unprotected terrestrial sites harboring irreplaceable biodiversity" by Dinerstein et al. proposes a strategic approach to protect areas that are crucial for preserving rare and threatened species. The authors define "Conservation Imperatives" as 16,825 unprotected sites spanning approximately 164 million hectares of the terrestrial realm, which harbor rare and threatened species. They estimate that protecting these sites would cost around US$169 billion. The study highlights that 38% of these sites are either adjacent to or within 2.5 km of existing protected areas, potentially reducing land acquisition and management costs. The authors emphasize the urgency of prioritizing these sites for conservation action over the next five years as part of a broader strategy to expand the global protected area network. They also discuss the need for multiple approaches, including land purchase, community reserves, and government re-designations, to meet long-term protection goals. The paper provides a detailed methodology for identifying and prioritizing these sites, including species rarity layer mapping, fractional land cover analysis, and cost assessment. The results show that only 7% of new protected areas created between 2018 and 2023 overlap with unprotected species rarity sites, indicating a need for more strategic planning. The authors conclude that protecting these sites is both affordable and achievable, and they offer a starting point for guiding biodiversity protection commitments from various sectors.