In Tikal and Yaxhá, the story I was told about the Mayas—as we walked through the lush green forest, wildlife sounds all around, and on the large paths and monuments taken over by the nature it was built on—was primarily about climate change.

The northern Guatemala topography is mainly forested flatland, so most ancient structures masquerade perfectly as hills and small mountains. The impressive Mayan constructions have taken archeologists years to uncover, with the now-visible ruins in constant threat of being taken over by sprouting shrubs and trees. Most of the labor and costs of maintaining these archeological sites are associated with keeping vegetation from growing, and roots from destroying, the ancient stone.

Perhaps it is a sort of delayed retribution on nature’s behalf, given that the Mayans deforested large parts of the area to extract cal (calcium oxide) from limestone. This important compound was the basis of all Mayan construction, which was mixed with water, sand or gravel to create cement and mortar. To produce cal, temperatures greater than 1400°C (>2500°F) are needed, which translates to a lot of wood being cut and burned in specialized kilns around 900 C.E.

The amount of deforestation shifted the microclimate of what is now the Maya Biosphere Reserve in the Petén, causing major environmental changes that affected wildlife habitats, rainfall patterns, soil composition and fertility—amongst other consequences—leading the Mayans to lose the seasonal predictability that they depended on for food and sustenance.

It is said that the Mayan calendar, which was meant to predict “the end of the world,” actually indicates the end of an erroneous way of thinking for the Mayas. Somehow realizing the consequences of their destructive behaviors towards the environment, legends and paleoenvironmental evidence say that the Mayans changed their ways and cultivated respect and harmony with the earth. Some of the research I have encountered theorize that the Mayans became master agro-foresters, strategically planting shrubs and trees for food, sustainably harvesting and conserving the forest resources they needed.

Sadly, the story ends in the same colonialist decimation of the people and culture, as fated to all of the Americas. In the Petén, the ancient ruins of this massive, long-lived civilization is present everywhere – buried beneath mountains, emerging from the ground when it is eroded by rain, or hidden at the bottom of a lake. But, the lesson may have been forgotten, and now it is occurring at a macro, global scale—a story of unsustainability and climate change, repeating itself.