The Huascarán Biosphere Reserve in Peru is situated in the Cordillera Blanca, the highest tropical mountain range in the world, with 27 snow-capped peaks. The impacts of climate change have been assessed continually between 1970 and 2003, and it is estimated that about 22% of the glaciated area of the Cordillera Blanca has disappeared. In addition, many of the smaller, lower-lying glaciers in the reserve are predicted to disappear within a few decades. Glaciers on Mount Huascarán have lost at least 13 km² of ice and about 40% of area compared to 37 years ago. Recent research on catchments in the Cordillera Blanca suggests that the complete melting of the glaciers would lead to a decrease in annual dry season discharge of 30% to 60%, depending on the watershed. 

The Sundarbans Biosphere Reserve in India is home to the world’s largest mangrove forests. Mangroves are rare but spectacular ecosystems that occupy the boundary between land and sea. The conservation of mangrove areas is of great importance, as these trees function as ecosystems engineers, helping to sustain and shape their environment. Continuous natural subsidence in the Sundarbans causes sea level to rise by about 2.2 mm every year. If the sea level were to rise by 45 cm worldwide as a consequence of climate change, 75% of the Sundarbans mangroves could be destroyed, with devastating impacts on many endangered species including the estuarine crocodile, Indian python and the iconic Bengal tiger.

The Galapagos Islands are a unique ‘living museum and showcase of evolution’. In 1984 they were designated a biosphere reserve. The ecosystems of the islands are high in diversity and endemism, and home to unusual animal life forms including the land iguana and the giant tortoise. Past climate events are key to understanding how climate change will affect the future of the Galapagos. In particular, strong El Niño Southern Oscillation (ENSO) events have shaped the living communities of the archipelago over millennia. Recent strong events in 1981–82 and 1997–98 resulted in the disappearance of cold-water upwelling, which is rich in nutrients, and the consequent starvation of marine ecosystems. Vital species sustaining entire communities were devastated, with a decrease in coastal fauna breeding, changes in nesting patterns, and a rise in the mortality rates of birds, reptiles and sea lions. Climate change has the potential to cause rises in sea level, sea temperatures, ocean acidification and rainfall, all of which would exacerbate regional ENSO climate impacts.

UNESCO Biosphere Reserves are ideal spaces to set up and improve comprehensive learning processes in the context of climate change.