The rapid retreat of the glaciers has long been one of the clearest indicators of climate change. In Peru, home to the largest collection of tropical glaciers in the world, glaciers have shrunk 50% in the past 50 years, ushering in new problems for downstream communities, from more frequent avalanches to fears about future supplies of freshwater.
Less attention, however, is paid to the risk of worsening water quality in glacier-fed basins in the Andes. As glaciers melt, they expose long hidden sediments to the elements, producing acidic meltwater laden with heavy metals that can harm people, livestock, crops, and ecosystems. A growing body of research describes “acid rock drainage” from glacier retreat as a threat to water security. Some rivers now run red with acidic water, offering a striking visual of how climate change transforms landscapes and makes the world less livable.
This reporting project uses photos, text, and interactive maps to explore how Andean communities in Peru are affected by acid rock drainage and how they are adapting. One village, for example, has developed a water monitoring system and built filtration systems.
A reporter traveled to Peru’s Cordillera Blanca mountain range to document the experience of that community and others. Reporting also includes water samples taken in at least one village to send to a lab for analysis, as well as interviews with experts to describe the extent of the problem and data from the Peruvian Mountain Institute to create an interactive map on glacier retreat and water quality.
