| Feature | 2018 Benchmark | Milestone for 2030 | Target outcome for 2050 | References |
| Protecting natural habitats and species | ||||
| Global percent natural habitat protected | ||||
| Global surface protected area coverage for Terrestrial, Freshwater, and Marine Realms | Under Aichi Biodiversity Target 11 currently: (i) 14.9% of the world’s terrestrial and inland waters, and (ii) Approximately 4% of the global ocean is covered by implemented MPAs but only 2% in fully protected areas | 30% in protected areas: (i) 30% of terrestrial surface (incorporates freshwater), strategically located to better protect biodiversity and biosphere function (ii) at least 30% of each ocean habitat in fully to highly protected MPAs (iii) an additional 20% surface area designated as CSAs | 50% in protected areas composed of: (i) 50% of terrestrial surface (incorporates freshwater), strategically located to better protect biodiversity and biosphere function (ii) networks of fully to highly protected MPAs cover at least 30% of exclusive economic zones and 80% of the high seas | (24, 40, 43) |
| Biodiversity representation by ecoregions (terrestrial and freshwater) | ||||
| Ecoregion-based representation in global protected area system | (i) Less than half of the world’s 846 terrestrial ecoregions have at least 17% of their area in protected areas (ii) Only one-third of the 232 marine ecoregions (coastal) have at least 10% of their area protected | (i) 300 terrestrial ecoregions have reached half protected; 563 terrestrial ecoregions have reached 30% protected (ii) All marine ecoregions have reached at least 30% protected | (i) 650 terrestrial ecoregions half protected (ii) All marine ecoregions at least half protected | (16) |
| Priority natural sites and species within ecoregions | ||||
| Alliance for Zero Extinction sites | 56% of 600 AZE sites protected | 100% of 600 sites are effectively conserved including 1-km buffer | 100% of target species have IUCN status improved | (46) |
| IUCN range rarity of vertebrate species | Rasterized map of hotspots | 50% of areas identified on map of hotspots of range rarity protected | 100% of areas with hotspots of threatened and small-ranged species protected | (92) |
| Key Biodiversity Areas | 15,000+ KBAs identified as of 2018; 60% protected in 2018 | 90% of extant and future, formally identified KBAs are protected, including a 1-km buffer around all KBAs | 100% of extant and future, formally identified KBAs are protected, including a 1-km buffer around all KBAs | (27) |
| High Biodiversity Importance Ecoregions | 455 HBIEs | 11.4% new protected areas added to reach 30% globally | Addition of all other megafaunal areas overlapping with carbon sinks as CSAs | Fig. S1H |
| Specific management actions targeting wide-ranging megafauna and large mammal migration routes | As examples, range collapse and steep declines in populations of African elephants, most rhinoceros species, and many tiger populations. Rampant poaching in many regions; historic migration routes of large mammals under threat from development | (i) Populations of 10 target species are doubled from 2018 baseline by 2030 (ii) Sport and commercial hunting of endangered megafauna and all trade in live animals and parts are banned (iii) 10 migration hotspots are secured and routes protected as globally recognized corridors | (i) Populations of 20 target species are doubled (ii) Restoration of relatively intact megafaunal assemblages in 40 priority landscapes (iii) 20 migration hotspots are secured and protected as globally recognized corridors (iv) Achieving the above three targets leads to a delisting of these megafaunal species by the IUCN Red List | (28, 49, 71) |
| Primary habitats | Combined, old-growth or intact habitats across all biomes cover less than 23% of the Earth’s surface; for some biomes, few large examples remain | 80% of 2018 extant is placed in protected areas or OECMs | 100% of old-growth habitats under protected areas or OECMs | (15) |
| Stabilizing and restoring ecosystem function | ||||
| CSAs as OECMs with the explicit goals of conserving the carbon storehouses and global forest cover | (i) Potential CSAs are currently intact and (ii) 2017 forest cover = 11.61 m km2 | (i) Designated CSAs are 80% intact and 80% conserved through OECMs (ii) International and national protection for all mangrove, coastal marshes, wetlands, seagrass beds, swamp forest, peat forest, peatlands by 2030 and (iii) 80% natural forest cover remains intact globally | (i) Designated CSAs remain intact as OECMs (ii) Increase in forest cover via Bonn Challenge and other means by 10% | (3) |
| Indigenous lands | Indigenous peoples’ lands account for 37% of all remaining natural lands on Earth and store >293 gigatons of carbon | High-priority indigenous lands that self-nominate and are identified as crucial to contributing to 2030 global targets are declared as OECMs with tenure and management financing secure | All high-priority indigenous lands self-nominated as OECMs receive designation, tenure rights, and support for management effectiveness | (74) |
| Maintain and restore connectivity of terrestrial protected areas | 7.5% terrestrial protected areas well connected | 20% terrestrial protected areas well connected | 40% protected areas well connected | (37) |
| Maintain and restore connectivity of inland waters | More than 800,000 dams and 45,000+ large dams exist; more than half of the world’s rivers blocked by large dams, thousands of smaller dams being planned, 35% of wetlands have been lost since 1970 | (i) No further planning or building of large- to medium-sized dams on the world’s rivers; concentration of dams on tributaries with existing structures (ii) Maintain two-thirds of all headwaters of the Earth’s major river systems undammed by 2030 through protection and removal of blocking infrastructure (iii) Protect and restore riparian habitats along one-third of all rivers by 2030 (iv) Adequate protection and 1-km buffer zones for all RAMSAR wetlands by 2030 (v) Protection of one-third of the world’s forested upper watersheds by 2030 | (i) Restoration of 25% of the world’s rivers to free-flowing state by 2050 through removal of dams and barrages (ii) Protection and restoration of riparian habitats along two-thirds of all rivers by 2050 (iii) Adequate protection and 1-km buffer zones for all globally mapped wetlands by 2050 (iv) Protection of one-half of the world’s forested upper watersheds by 2050 | (57, 93) |
| Maintain and restore connectivity of marine waters | Scant formal protection of critical marine habitats (reproduction, nurseries) for threatened species and migratory corridors for endangered species of fish, marine mammals, and sea turtles | (i) Full protection of all critical habitats (reproduction, feeding, and nurseries) for threatened species (ii) Full protection of critical migratory corridors within local networks of MPAs for endangered species of fish, marine mammals, and sea turtles | (i) Full protection of all critical habitats (reproduction, feeding, and nurseries) for commercial and threatened species (ii) Full protection of critical migratory corridors within local networks of MPAs for commercial and endangered species | |