The IUCN World Heritage Outlook 4 has been launched!
Global outlook
The results of the IUCN World Heritage Outlook 4 indicate that for 61% of sites (165 sites) the conservation outlook is either “good” or “good with some concerns”, while for 33% (88 sites) the outlook is of “significant concern”, and for 6% (17 sites) it is assessed as “critical”. For one site (Lena Pillars Nature Park, Russian Federation) the conservation outlook is “data deficient”.
The overall picture of the conservation outlook for natural World Heritage sites in 2025 remains similar to the overall results in 2020, but with a slightly downward trend. There was a 2% decrease in sites assessed as “good”, a 2% increase in sites assessed as “significant concern”, though a positive result of a 1% decrease in sites assessed as “critical”. Overall, conservation prospects are positive for less than two-thirds of all assessed sites, indicating that further significant efforts are required to improve the outlook of many sites.
Looking at the comparative results of 228 sites for which four datasets are now available, the IUCN World Heritage Outlook 4 shows that the percentage of sites with a positive conservation outlook has for the first time decreased significantly since 2014. While 63% of sites had a positive outlook in 2014 and 2017 and 62% in 2020, only 57% of sites have a positive conservation outlook in 2025. The indicative trends from the IUCN World Heritage Outlook 3 have become more pronounced, with a notable increase in the percentage of sites assessed as “significant concern” (from 31% in 2020 to 35% in 2025) and a decrease in the percentage of sites assessed as “good” (from 18% in 2020 to 15% in 2025) or “good with some concerns” (from 44% in 2020 to 42% in 2025).
Changes in conservation outlook
Over the past decade, the conservation outlook of 70 sites in total changed at least once; 29 improved; 40 declined; and one moved to “data deficient”. While for many sites there has been a consistent overall direction of trend, for a few sites there has been a fluctuation in the conservation outlook.
A comparison between 2020 and 2025 shows that a total of 41 sites changed their overall conservation outlook with 27 decreasing, 13 improving and one moving to “data deficient”. This reflects the prevailing negative trend from 2020 where 16 sites decreased and 8 improved. Notably, 14 sites changed their outlook from “good with some concerns” to “significant concern” between 2020 and 2025.
Climate change, invasive alien species and tourism remain the top threats
Climate change remains the most prevalent current threat and continues to impact an increasing number of sites.
Overall, changes in physical and chemical regimes, changes in precipitation and hydrological regimes and/or changes in temperature regimes were assessed as high or very high threats in 43% of all sites. Since 2020, the number of sites where climate change is a high or very high threat has increased by 31 sites, making climate change the fastest growing threat.
Invasive alien species remain the second most prevalent current threat affecting 81 out of the 271 sites assessed, while recreational activities are the third most significant threat globally, followed by hunting, fishing and the development of recreation and tourism areas.
A notable and in some cases linked concern is that pathogens (causing diseases impacting plants and animals), have seen a significant increase in the number of sites where this was assessed as a high or very high threat, from two sites in 2020, to 19 sites in 2025, when focussing on the 228 sites assessed since 2014. In total, out of the 271 sites assessed in 2025, pathogens were a high or very high threat in 23 sites.
Current threats assessed as high or very high in 2025, 2020, 2017 and 2014
Climate change again tops the list of potential threats in 2025, as in the past two cycles, however, there has been a substantial decrease in the total number of sites in which climate change has been listed as a potential high or very high threat from 71 sites in 2020 to 40 sites in 2025. Pathogens have shown the largest increase in comparison to the previous cycle with 7 more site assessments reporting pathogens as a potential high or very high threat. While potential mining, oil and gas development, and hydropower projects continue to be among the most prominent potential threats assessed as high or very high, it is notable that there has been an increase in the number of sites potentially affected by road and railroad developments, which now represents the second highest potential threat (along with mining and quarrying). Furthermore, invasive alien species represents the fourth most prominent potential threat to the assessed World Heritage sites, although the number of sites potentially affected by this threat has only increased by one site since 2020.
Potential threats assessed as high or very high in 2025, 2020, 2017 and 2014
The effectiveness of protection and management remains of concern
The 2025 results for all 271 natural World Heritage sites show that 50% of sites have overall effective or highly effective protection and management, whilst this is not the case in the other 50%, including 8% of sites in which protection and management were assessed as of serious concern.
While overall, the proportion of effectively managed sites has not changed substantially, when focussing on the 228 sites for which there are now four datasets available, there has been a continued decrease (since 2014) in the percentage of sites where management is assessed as of serious concern. This indicates that management effectiveness has improved for the most threatened sites. However, since 2020, there has also been a notable decline in the percentage of sites where management is considered highly effective, from 10% in 2020 to 5% in 2025.
For all sites assessed in 2025, management effectiveness in addressing threats outside site boundaries was of some or serious concern for 62% of sites. This has remained unchanged since 2020. When looking at the 228 sites assessed since 2014, there has been a further decrease in management effectiveness in addressing threats outside site boundaries with concerns in 65% of sites in 2025 compared to 61% in 2020. With several of the greatest threats originating from outside site boundaries, effective site-level management is not sufficient to secure a positive conservation outlook without stronger regional, national and global support.
Number of sites where specific protection and management aspects were assessed as highly effective in 2025 (top six categories)
Number of sites where specific protection and management aspects were assessed as being of serious concern in 2025 (top six categories)
An improved outlook remains possible
Comparing the outlook of sites in 2014 and in 2025, 15 sites with previous concerns progressed to the achievement of a good outlook. The conservation outlook for 14 sites moved from significant concern to good with some concerns and one from critical to good with some concerns. Comoé National Park in Côte d’Ivoire, is a flagship example, being removed from the List of World Heritage in Danger due to concerted efforts by the State Party and numerous partners to enhance anti-poaching measures, manage livestock grazing, and meaningfully engage local communities in decision-ma king processes.
Between 2020 and 2025 four sites in West and Central Africa saw an improvement in their conservation outlook from critical to significant concern. Enhanced anti-poaching efforts, strengthened relationships with local communities and the stabilisation of key animal populations are leading to an improved outlook in Dja Faunal Reserve (Cameroon), Salonga National Park, Garamba National Park (both Democratic Republic of the Congo) and Niokolo-Koba National Park (Senegal), demonstrating remarkable resilience in the face of long-term challenges.
These achievements demonstrate that concerted local action can effectively improve the conservation outlook of World Heritage sites. However, global partnerships and regional commitments are essential to maintain such positive developments, scale up action in other sites and inspire further success stories in the face of growing challenges.
The many stories of determination and success happening at the ground are detailed in the 271 Conservation Outlook Assessments available online on worldheritageoutlook.iucn.org.