UNESCO Report: Climate Change Threatens Over 1,200 World Heritage Sites by 2100 Under Current Trajectories

Paris, 6 February 2026 — UNESCO today published a landmark assessment on the intersection of climate change and cultural and natural heritage, finding that under current greenhouse gas emission trajectories, more than 1,200 World Heritage properties — over half of all inscribed sites — face significant or severe climate-related risks by the end of the century.

Magnitude of the Threat

The assessment, produced in collaboration with the International Union for Conservation of Nature (IUCN), synthesises climate projections for all 1,199 currently inscribed sites. It categorises threats into five domains: rising temperatures, altered precipitation patterns, sea-level rise, extreme weather events, and ocean acidification.

Coral reef systems inscribed on the World Heritage List — including the Great Barrier Reef (Australia), the Belize Barrier Reef System, and the New Caledonia Barrier Reef — face existential threats from a combination of thermal bleaching, ocean acidification, and intensified cyclone activity. Under a 1.5°C warming scenario, annual bleaching events are projected to occur at three-quarters of inscribed reef sites.

Glacial landscapes, including the Swiss Alps Jungfrau-Aletsch site and the Dolomites (Italy), are experiencing rapid and irreversible ice retreat. UNESCO projects the effective disappearance of the principal glacial features of several inscribed sites within decades.

Low-Lying Coastal Heritage Cities

Among the most complex vulnerabilities identified in the report are those affecting historic port cities and low-lying urban heritage sites. Cities such as Venice (Italy), Lamu Old Town (Kenya), and the Old Town of Galle (Sri Lanka) face compounding risks from sea-level rise, storm surges, and saltwater intrusion affecting subsurface foundations and structural integrity.

UNESCO's Climate Action for World Heritage

UNESCO's Climate Action for World Heritage programme provides a structured framework for integrating climate risk assessment and adaptation planning into Heritage Management Plans. The report urges all States Parties to submit or update climate adaptation strategies for all inscribed properties by 2028.

UNESCO also calls for significant increases in climate finance directed towards heritage adaptation, noting that current flows represent less than 0.01 per cent of total international climate finance.