UNESCO’s 207 natural heritage World Heritage Properties are at risk from climate change, but risk varies widely among properties. I offer a global model based on multi-model general circulation model (GCM) ensembles, vulnerability and Human Influence (HII), producing the World Heritage Vulnerability Index (WHVI), a measure of relative risk among properties. Nineteen properties are most at risk (i.e. WHVI > mean + 1 SD). Those include islands (i.e. Vallée de Mai, Aldabra, East Rennell, Teide, Laurisilva of Maderia, Isole Eloie, Pitons Management Area, Morne Trois Pitons and Galapagos Islands), coastal properties (i.e. Everglades, Desembarco del Granma, High Coast and Kvarken Archipelago, Doñana, Brazilian Atlantic Islands, Ichkeul and the Sunderbans) and mountainous properties (i.e. the Pyrenees Mont Pérdu, Nanda Devi and the Valley of Flowers, and Mount Kinabalu). Three properties (i.e. Teide, Isole Eloie and the Pitons Management Area) are geologic, apparently relatively resistant to short-term climactic changes. The remaining 16 are likely to respond to climactic changes in the next 40 years; those changes may threaten their World Heritage status. Those properties are where society could most effectively invest in adaptation. I identify adaptive strategies and next steps for proactive climate change adaptation in the 16 natural heritage properties on the World Heritage List most at risk.