19 OCT 2026 — The official global tally says 18.5% of the world's land is conserved. A study published in Nature on 14 October 2026 puts the figure at 26.81%, nearly 27%, after counting conservation areas missing from global records. If that holds, the land half of the global "30 by 30" pledge is much closer than the official numbers suggest. The first author is Helen O'Neill of the University of Kent's Durrell Institute of Conservation and Ecology and the Zoological Society of London.
The open-access paper also has a less encouraging finding. Much of the extra land lies in ecoregions that are already well covered, so counting it does little to close the gaps that matter most for wildlife.
What the 30 by 30 target asks
Governments that are party to the Convention on Biological Diversity, 195 of them, agreed in 2022 to raise the global coverage of protected areas and "other effective area-based conservation measures" (OECMs) to at least 30% by 2030. The pledge is Target 3 of the Kunming-Montreal biodiversity framework, adopted the same year. Its official text also requires those areas to be effectively managed, well connected, equitably governed and ecologically representative, which is a longer list than a single percentage.
The official tally comes from a global database of protected and conserved areas (WDPCA) run by the UN Environment Programme's World Conservation Monitoring Centre and the IUCN. On those figures, the world needs another 11.5% of its land, about 15.5 million square kilometres, to reach 30%. The paper says that database is made up mostly of state-run protected areas, because most countries have only recently started mapping and reporting other types.
How the team counted the missing land
Gathering national data from every country would take years, so the group used a sample. An earlier paper in Oryx, by O'Neill, her Kent colleague Zoe Davies and others, had picked 10% of the world's land across 25 countries and territories, chosen to mirror ten factors that shape where conservation areas exist, from income and population density to biome and latitude. A random 10% of the world's land would have touched about 162 countries.
Within that sample the researchers pulled together 65 national and subnational datasets on top of two global ones. Fifty-one of those national datasets are not public. They were shared on condition that results would not be published country by country, and the paper reports only a global figure for that reason.
The three layers behind the estimate
The 26.81% breaks into three layers. Globally recognised protected areas account for 15.79%. Another 3.64% is protected areas that appear in national records but were never reported to the global database, because of reporting delays, data restrictions or national laws that do not recognise privately run reserves. The last 7.38% is land the authors class as "possible OECMs", sites under long-term governance and management that already conserve nature but have not been formally recognised. Many are expected to be run by private owners, Indigenous Peoples or local communities.
That final layer carries a large caveat. The authors measured possible, not actual, OECM coverage. Formal recognition needs the free, prior and informed consent of the people who govern each site, some of whom are wary of official listing. On the paper's arithmetic, "we may only be 3.2% short of achieving 30% coverage". The estimate is pinned to 2022 data and is probably still an undercount, since some countries do not have the means to map all of their conservation areas.
Why more land does not mean more nature
The authors scored each network for "protection equality", where 1 means every ecoregion is equally covered. Globally recognised protected areas scored 0.405. Adding the newly counted land lifted that only to 0.505.
The ecoregion counts show why. Of a median 173 ecoregions in the sample, 80 had under 10% of their area in globally recognised protected areas, and 51 still did after every type of conservation area was added. Existing protected areas tend to sit on economically marginal, remote or upland land, and the possible OECMs are largely found in the same ecoregions. Only 2.5% of the land across all three categories was highly suitable for agriculture.
The authors are blunt. Meeting the area figure alone "will do little to solve continuing global biodiversity loss". They argue for better management of existing sites and for new ones placed through systematic planning in under-represented ecosystems.
Where Southeast Asia sits in the sample
Indonesia is one of the 25 countries and territories in the sample, according to the list in the earlier framework paper, alongside China, India, Papua New Guinea and Australia. Four of the Nature paper's co-authors are affiliated with the Working Group ICCAs Indonesia in Bogor. Because the national data were shared on condition of confidentiality, the paper gives no figure for Indonesia or any other country.
For governments, the practical message is about recognition. The authors say OECMs and wider forms of protected-area governance could credit Indigenous Peoples and local communities, who govern large parts of the world but are under-represented in formal networks, provided they consent and governments fund the process.
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