What Caused the Collapse of the Mayan Empire? (hint - drought!) - PAESTA Podcast Series: Episode 8
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Transcript for the podcast
Hi, I’m Sadie and today we’re going to explore what caused the collapse of the Mayan Empire. The Mayans were a complex and fascinating civilization living around the Yucatan peninsula in Central America between the years 250 and 1100 CE. That particular region of Central America, parts of Mexico, Guatemala and Belize, experienced what are referred to as seasonal droughts. Seasonal droughts are periods throughout the year that experience little or no rainfall. In months that did experience the rainfall, up to 90 percent of the year’s precipitation overall would occur in that time frame.  The Mayan empire developed methods of collecting and preserving the rain in giant reservoirs across the region that could store their fresh water. These reservoirs replenished naturally during the rainy season and sustained the Mayans through the seasonal drought.  One of the most fascinating aspects of the history of the Maya is their mysterious collapse just at their peak in history. There wasn’t evidence to support that they died, meaning that they left. So the question became, what caused them to leave? This is the question we’re going to explore today. There is evidence to support shifts in political power causing them to disperse, as well as uprising among their people against their government, but the evidence points most to drought as the leading cause of their collapse.
When researchers examined the evidence, they found that there was a correlation between the time in history that the Mayans fled and when the largest drought of the Mayan Classical period occurred. Both dated back to about 800 to 900 CE. Now, there are many things that could have contributed to the drought. One of the possible contributors were the agricultural practices of the Mayans. It may have contributed to the climate change that inevitably resulted in the long periods of drought that drove them out. This happened overtime as they began cutting down forests to burn as firewood and make space for fields to grow corn, which is a very thirsty crop. Studies funded by the National Aeronautics and Space Administration, also known as NASA, used a computer simulation of the deforestation to predict how it would have affected the climate. Interestingly, the result was that 100 percent deforestation could, in the long run, cause a 20-30 percent decrease in rainfall as the result of temperature increase by just a few degrees.  This is when scientists concluded that drought is what ultimately drove the Mayans away.
In addition to the evidence that lies on land, there was evidence in Mayan sacred sites that indicated the people were responding to a drought. After making many discoveries, like the one in the Cara Blanca site in Belize, it was clear that Mayans were reaching out to the gods in an attempt to receive more water. Many Mayan artifacts that dated back to the time of the collapse, were found in the bottom of natural pools at the location of sacred sites. According to archaeologists, the Mayans would travel to these sacred temples to make offerings to the water gods in hope for rain. **There have been discoveries of ceramic pots and tools that traveling Mayans deposited into the sacred sites as offerings over time. In another site found in Caracol, a city in Belize, another sacrificing ground was found deep inside a pyramid in the opening of a cave. The site was used as a place of ritual, where many more of these offerings were made. These discoveries from the bottom of the pools and in the openings of caves were dated back to just before the collapse of the empire, right before the Mayans fled. Making sacrifices such as these were not necessarily new to the Mayans, however, the sacrifices of these tools and artifacts occurred much more frequently just before the drought. This suggested that the Mayans were dealing with the consequences of the drought they were experiencing. 
So, to summarize, the Mayans were very advanced for their time, the technology they used to build pyramids and store water and irrigate their crops was amazing. The drought they experienced just as they reached their peak in history created tension among their people and devastation to crops that led the Mayans to eventually flee in search of water. Most of the collapse of the Mayan civilization has been linked to the long period of droughts they experienced.
(This audio file was recorded by Sadie Lenardon, undergraduate student at Penn State Brandywine, on March 7, 2016. References are in attached transcript.)
Earth Science Literacy Principles
Big Idea 1. Earth scientists use repeatable observations and testable ideas to understand and explain our planet.
1.3 Earth science investigations take many forms
Big Idea 3. Earth is a complex system of interacting rock, water, air, and life.
3.1 The four major systems of Earth are the geosphere, hydrosphere, atmosphere, and biosphere.
3.6 Earth’s systems are dynamic; they continually react to changing influences
Big Idea 5. Earth is the water planet.
5.2 Water is essential for life on Earth.
Big Idea 7. Humans depend on Earth for resources.
7.1 Earth is our home; its resources mold civilizations, drive human exploration, and inspire human endeavors that include art, literature and science.
7.2 Geology affects the distribution and development of human populations.
7.5 Water resources are essential for agriculture, manufacturing, energy production and life.
Big Idea 8. Natural hazards pose risks to humans.
8.3 Human activities can contribute to the frequency and intensity of some natural hazards.