Natural world heritage sites face increasing risk under rapid climate change, especially considering the impacts of climate extremes. However, there is not yet enough understanding of the future extreme climate challenges at global natural world heritage sites. Here we identify the exposure of 250 natural heritage sites to extreme climate events under 4 different future scenarios. We found that by 2100 under the highest emission scenario, 248 out of 250 sites were exposed to extreme climate events. Forest natural world heritage sites may face increasing pressure to complex extreme phenomena under emission rise. In tropical regions, where high temperatures may magnify the vulnerability of biodiversity, we identify 14 natural world heritage sites to be prioritised that are poor in biodiversity and expected to face high temperatures. Hence, there is an urgent need for enhanced climate change adaptation at heritage sites to minimise loss of irreplaceable values.

Space technology offers effective tools to monitor the status of World Natural Heritage sites. East Rennell Island, which covers approximately 37,000 hectares (ha) and a marine area extending three nautical miles into the sea, was added to the list of endangered World Natural Heritage sites in 2013. Deforestation and natural disasters have increasingly threatened sustainable development on the island. Based on analyses of multi-source time series of remote sensing data (e.g., MODIS and Worldview), the forest cover change on Rennell Island from 2000 to 2020 and its future trends were mapped and analysed using Sen + Mann–Kendall and Hurst index models. A land cover classification system derived from high-resolution Worldview images was developed as a baseline for monitoring and analysing future forest cover changes on the island. Our results showed that (1) the areas of vegetation degradation and improvement were basically equal from 2000 to 2020. (2) The forest cover change trend had weak continuity, and significant improvements could be achieved in areas with damaged vegetation given sufficient protection measures and financial input. (3) This heritage site has a strong vegetation regeneration ability, and human activities such as mining, logging, and road construction, which could greatly disturb the unique ecosystem, should be restricted.

Space technology is an effective approach to monitor the status of World Natural Heritage sites. East Rennell Island has been inscribed on the List of World Heritage in danger since 2013. The site includes approximately 37,000 hectare (ha) and a marine area extending three nautical miles to sea. Deforestation and natural disasters have become the increasing factors threatening its sustainable development. Based on the analyses of multi-source long-time series remote sensing data like MODIS and Worldview data, the forest cover change and its future trends in Rennell Island from 2000 to 2020 have been mapped and assessed using Sen + Mann-Kendall and Hurst index models. A land cover classification system derived from the high-resolution Worldview images was developed as a baseline product for monitoring and analyzing future forest cover changes in East Rennell Island. Our results show that: (1) Area of the vegetation degradation is basically same as that of vegetation improvement from 2000 to 2020. (2) The trend of forest cover change is weak in continuity, and significant improvements in damaged vegetation can be implemented but it needs enough protection measures and financial input. (3) This heritage site has a strong ability to regenerate vegetation, and it is recommended to restrict the human activities like the mining, logging, and road construction, which could greatly disturb the unique ecosystem.

Achieving the Paris Agreement goal of limiting warming to 1.5°C without a temporary overshoot has become increasingly difficult. Climate overshoot has therefore shifted from a theoretical possibility to an increasingly plausible future. Although heatwaves are known to threaten human health and intergenerational equity, how overshoot pathways reshape lifetime exposure and age-dependent health risks remains poorly understood. Here we combine CMIP6 climate projections, demographic data and age-specific heat vulnerability estimates to quantify lifetime heatwave exposure and associated health risk under the SSP5-3.4OS overshoot scenario. We find that climate overshoot fundamentally reshapes the distribution of generational risks: lifetime exposure peaks among cohorts born around 2040, whereas weighted heatwave-related health risk peaks about two decades earlier, among cohorts born around 2020. Under more ambitious mitigation pathways represented by the IPCC AR6 C2 category, peak health risks are reduced by nearly half, and the highest-risk cohort shifts to earlier birth years. Our results show that intergenerational inequities depend strongly on the timing and magnitude of climate overshoot, highlighting the need for early, front-loaded mitigation to limit peak risks and reduce heat-related health inequities across generations.