I just finished my undergraduate capstone in anthropology. The question that drove it was simple. When the glaciers go away, what happens to the people who built their lives around them?
The place I focused on is the Cordillera Vilcanota in southeastern Peru. This mountain range holds the largest tropical ice cap in the world, and its meltwater feeds one of the headwaters of the Amazon. Indigenous Quechua communities have lived in its shadow for centuries. The peaks are not just scenery to them. The biggest one, Ausangate, is treated as a living being.
Those glaciers are disappearing. The Vilcanota has lost about a quarter of its ice since the mid-1970s, and the rate of loss has more than doubled in recent years. The communities below are paying attention.
Here are three things I learned that I think are worth knowing, whether or not you have ever heard of any of these places.
1. There is more than one way to read the weather.
When most of us check the forecast, we open an app. The communities I researched use at least three different ways of reading the world, and they are not interchangeable.
The first is astronomical. Around the winter solstice in late June, farmers look at the Pleiades star cluster in the pre-dawn sky. How bright or fuzzy the stars appear correlates with how the upcoming rainy season will behave. This is not folklore. Researchers have shown that the practice forecasts rainfall about as well as modern meteorology does at similar lead times.
The second is cosmological. Communities perform ceremonies of gratitude to the mountains, called apus, and to Pachamama, or Mother Earth. The mountain is treated as a partner in an ongoing exchange. The water it gives is matched by offerings the community gives back.
The third is embodied. Herders, mostly women, spend their days with alpacas and llamas at the edge of viable grazing land. They read climate change through the behavior of their animals. They watch where the herds want to walk, what they will and will not eat, and how their bodies are holding up.
These are three different kinds of knowledge. All of them are generated in different ways. All of them are under pressure from a destabilizing climate, and each is adapting on its own terms.
2. The adaptations that last come from the inside.
In February 2026, a wet, lingering storm hit the Ausangate region during what should have been the mild months of the rainy season. People had to clear snow from grazing areas with sticks because they did not own shovels for that kind of weather.
Some farmers had planted their potatoes early, following traditional astronomical readings. Others planted later. The ones who planted early lost very little, because their crops had matured enough to survive the storm. The ones who planted later asked the government for help, and the government barely showed up.
Now compare that to what happened with greenhouses. About fifteen years ago, an international development organization helped install greenhouses in the village of Pukarumi. These small structures let families grow vegetables year-round despite frosts and hail. Families adopted them. They built the adobe walls using their traditional reciprocal labor system. They fertilized the plants with manure from their own herds.
Then the organization left Peru. The plastic roofing wore out. There is no local source for replacement plastic, and individual families cannot afford to buy it from Cusco. So the greenhouses sit, walls intact, roofs broken, waiting on a single missing piece.
The pattern is consistent. Adaptations that grow out of a community’s existing way of doing things tend to last. Adaptations dropped in from outside tend to be fragile. When the outside support leaves, the technology can flip from being an asset into being a liability.
3. Climate change is not only physical. It is relational.
There is a prophecy from the community of Paqchanta about Ausangate. The mountain will turn grey, then black, until it becomes a mountain of black cinder. The world as it is known will end.
I want to be careful here. This is not a climate prediction. The prophecy is about what happens when people stop honoring the mountain and the relationship breaks down. It is a moral story, not an environmental one.
That said, you can stand in Pukarumi today and look up at Ausangate and watch the mountain turn grey. The ice line is climbing. Rock that was white within living memory is now exposed stone.
For people who understand the mountain as a partner, the loss of glaciers is not only a water problem. It is also the loss of the visible evidence that the relationship still holds. A model of climate adaptation that can only count meters of ice misses what is actually being lost.
Why this matters beyond the Andes
If you take one thing from this research, take this. Climate adaptation works best when it is led by the people living through the change, on terms that match how they already understand the world. Outside help can matter, but only if it is designed to keep working after the people who designed it have gone home.
That principle applies far beyond a remote stretch of Peru.