Climate change is now the most significant risk for World Heritage sites and for the benefits they provide, including economic well-being through sustainable tourism, confirms a new report by UNESCO, UNEP and the Union of Concerned Scientists (UCS) in collaboration with IUCN, International Union for Conservation of Nature.

The new report offers a set of recommendations to address issues related to climate change at the level of the World Heritage Convention. For instance, it recommends adding more wilderness areas to the World Heritage List, to support the adaptation and resilience of species and ecosystems. It also suggests assessing the vulnerability of sites to climate change.

"World Heritage sites face a range of threats, including large infrastructure projects, illegal wildlife trade and extractive activities," says Tim Badman, Director of IUCN's World Heritage Programme. "But climate change could multiply the harmful effects of these threats, and therefore we must take action to increase the resilience of these iconic places."

Climate change was identified as the biggest potential threat to natural World Heritage in the IUCN World Heritage Outlook, the first global assessment of natural World Heritage launched in 2014. The new report, World Heritage and Tourism in a Changing Climate, confirms this and uses a series of case studies to highlight the fact that climate change also puts cultural World Heritage sites at risk. It focuses on tourism to illustrate how climate change can both increase existing threats and create new ones, while at the same time affecting the social and economic benefits of World Heritage sites.

"Globally, we need to better understand, monitor and address climate change threats to World Heritage sites," says Mechtild Rössler, Director of UNESCO's World Heritage Centre. "As the report's findings underscore, achieving the Paris Agreement's goal of limiting global temperature rise to a level well below 2 degrees Celsius is vitally important to protecting our World Heritage for current and future generations."

The new report lists 31 natural and cultural World Heritage sites in 29 countries that are vulnerable to increasing temperatures, melting glaciers, rising seas, intensifying weather events, worsening droughts and longer wildfire seasons. It documents climate impacts at iconic tourism sites – including Venice, Stonehenge and the Galapagos Islands – and other World Heritage sites such as South Africa's Cape Floral Kingdom; the port city of Cartagena, Colombia; and Shiretoko National Park in Japan.

"Climate change is affecting World Heritage sites across the globe," says Adam Markham, lead author of the report and Deputy Director of the Climate and Energy Program at UCS. "Some Easter Island statues are at risk of being lost to the sea because of coastal erosion. Many of the world's most important coral reefs, including on the islands of New Caledonia in the western Pacific, have suffered unprecedented coral bleaching linked to climate change this year. Climate change could eventually even cause some World Heritage sites to lose their status."