How Climate Change Impacts Directly and Cascadingly the Andes

The Andes are the longest mountain chain worldwide, stretching 8,000 km or around 4,000 miles from the north to the south on the western side of South America. It covers seven countries: Venezuela, Colombia, Ecuador, Peru, Bolivia, Argentina, and Chile.

The mountain ranges are also an essential natural landmark in South America and a significant source of biodiversity for the continent. However, according to a new study, climate change is impacting this long mountain range, reshaping the landscape, and affecting the people and species living in the area.

The study “Detection and Attribution of Climate Change Impacts in Coupled Natural-Human Systems in the Andes,” published in Communications Earth & Environment in April 2025, examines the effects of climate change on the Andes, focusing specifically on areas located above 1,000 meters above sea level. This region encompasses various climatic conditions and is rich in biological and cultural diversity. Researchers have identified 133 distinct terrestrial ecosystems and many endemic species in the tropical Andes alone. These provide vital services and benefits to approximately 85 million people living in the highlands and major cities downstream.

The Andes are also home to extensive glaciers, particularly in Chile and Argentina, which have undergone substantial ice loss ranging from 30% to over 50% in surface area since the 1980s. This retreat is largely attributed to human-induced climate change. These glaciers serve as a crucial freshwater source for millions across South America and feed several major rivers, including the Amazon, the world’s largest river by volume.

There is strong evidence that glacier shrinkage has affected mountain ecosystems, disrupted cultural traditions and spiritual values, and, in some areas, diminished mountain tourism. In addition, glacier retreat and permafrost degradation linked to anthropogenic climate change have increased the frequency of natural hazards such as rockfalls, ice detachment, snow avalanches, and glacier lake outburst floods.

The El Niño–Southern Oscillation (ENSO), a dominant climate driver in the region, is also projected to intensify in frequency and strength. This could lead to more extreme events such as droughts, floods, heatwaves, wildfires, storms, landslides, and altered soil moisture, causing widespread socioeconomic and environmental damage across the Andes.

These changes also lead to the loss of cultural identity, human migration, and human health problems. Examining the impacts of climate change in the Andes, the study highlights the direct and indirect impacts of climate change. While human-caused climate change has played a role in the changes unfolding in the Andes, non-climate factors are also at play.  

The study shows that rapid glacier melting, more frequent droughts and floods, and reduced water availability are happening across the Andes, leading to a cascading impact on the environment and people’s lives.

The findings highlight the importance of understanding the complex interaction between the climate and human systems. They also point to the urgent need for smart, locally relevant climate adaptation strategies and policies to support communities as they respond to climate change.

Learn how climate change impacts the Andes by clicking the “Sources” below.