The Maya were undoubtedly among the great ancient civilizations of Mesoamerica. They flourished in the jungles of present-day Mexico (south), Guatemala and Belize. This mysterious ancient civilization was one of the most important ancient cultures to develop on our planet, noted for the Maya script which was the only known developed writing system of the Pre-Columbian Americas. However, the collapse of the Maya civilization during the ninth century A.D. is a major conundrum in the history of mankind and while numerous explanations have been put forward to explain, the three most significant causes of the decline of Mayan civilization are famine, epidemic diseases and climate change.
(Remains of a woman from Ancient Maya)
The classic period in Mesoamerica between 800 and 935 CE saw one of the most dramatic civilization collapses in history. Within a century, the civilization fell into a permanent decline. Surrounded by pyramids, temples and agriculture; the Maya discussed philosophy, developed an accurate solar-year calendar as well as a writing system. In one way, the Maya were victims of their success. Many scholars believe that the Maya were exceeding the carrying capacity of the ecosystem; by the ninth century, the Maya had exhausted the environment around them to the point where it could no longer sustain a very large population. Pre-classic Maya from 1000 B.C. – 300 A.D. practiced basic subsistence agriculture: slash-and-burn cultivation on small family plots. They planted mostly corn, beans and squash. Basic fishing was practiced on the coasts and as the Maya civilization advanced, the cities grew. Their population was growing much larger than could be fed by local production. The improved agricultural techniques had picked up some slack; however, the large population in the cities put great strain on the food production. At its peak, the Maya civilization was inhabited by 15-22 million people. The population was simply too large for political, social, and environmental resources available. Human bones from this time period show signs of severe malnutrition. Excavated graves of Mayan people including many premature infants between the ages of three to six show suffering of hunger. There is evidence such as the artifact of the skill above for vitamin deficiency and premature death. Examination of the bones also found that the children not only suffered from malnutrition but also anemia, a condition caused by a deficiency of iron in the blood. In this way, Ancient Maya slowly came to its collapse as a result of overpopulation and famine. This widespread hunger and malnutrition would have lowered the Mayan’s ability to resist disease, making them susceptible to getting sick.
(A picture is shown of how the Ancient Maya suffered from epidemic diseases such as smallpox)
Another factor to the decline of the ancient Mayan civilization was disease. A widespread disease can result in rapid depopulation. The Mayans lived near tropical rainforest areas and contagious diseases that are spread by parasites are common in rainforest regions. If some of the diseases such as malaria which is a disease that is carried and spread by infected mosquitoes, were to infect a person at a young age, it affects their health resulting in developmental issues as well as making them vulnerable to other illnesses later on in life. Specifically, due to an epidemic of the plant hopper-borne virus, maize mosaic virus (MMV), is proposed as a primary contributing cause of the collapse. Maize Mosaic virus is a devastating disease transmitted by the corn planthopper, an insect restricted to tropic lowlands. Major diseases in the tropics are assessed thus it has been serious only where corn is grown continuously through the year in wet or irrigated tropics. Corn was the main food for the Mayans and Maize Mosaic corn disease spread through pestered corns containing contagious diseases which were spread throughout the Mayan city-states. The infectious illnesses were spread into the Mayans system, resulting in the death of almost the entire Mayan population. With the lack of modern medicine, the distinguished and noble people had no idea how to treat the illnesses. Contagious diseases such as measles, mumps, cholera, and smallpox spread and killed about ninety percent of the Mayan population. This lead to the Mayan collapse and now, what is left are the city structures.
(Evidence of Tree Rings shown to determine climate change)
Lastly, climate change causes a catastrophic collapse in human history. Studies have shown that the Maya civilization collapsed due to a century-long drought which took place around the ninth century. However, the Maya contributed to the collapse of their civilization by transforming the land through removing nearly all of the forest and replacing it with agricultural crops. Though deforestation didn’t cause a drought, it amplified natural droughts when they occurred. Plants interact with the atmosphere; dark plants such as dense tropical forest absorb energy from the sun while lighter coloured plants reflect sunlight which cools the atmosphere. Water vapour needs to rise and condense to create a rainstorm while the cool air sinks. Without warm and unstable air rising into the atmosphere, rainstorms become less common. Since the Maya burned and cut down timber very fast, deforestation levels were high using wood for construction purposes as the cities expanded.  This causes lack of rain which helped raise temperatures on land. The energy of the sun would hit the bare ground either heating it up or causing water to evaporate from the soil. Without forests, there was less production of moisture in the atmosphere and croplands holding less water; causing droughts to deepen more as the suns energy heated the ground. Rainfall was declined and as crops replaced forests, more sunlight bounced back into space. Using dendrochronology, a study of tree rings to date environmental changes, a team from the University of Arkansas observed the Mayan drought through tree rings and concluded that the drought was more severe and prolonged than anything in the modern era. Trees can live for hundreds of years and can experience a variety of environmental conditions: wet years, dry years, cold years and much more. From this, researchers are able to determine the year of formation for each tree ring and analyzed what the rings’ growth patterns had to say about how soil moisture varied from growth season to growth season over the years, a parameter directly associated with rainfall. Using dendrochronology, researchers are able to determine the climate changes that affected the ancient Maya and the drought that overcame them.
In conclusion, although the Ancient Maya were among the great ancient civilizations of Mesoamerica, building cities with elaborate ceremonial center, and their downfall remains a mystery. However, the three utmost reasons that contributed to their collapse are famine, epidemic disease and climate change.
 Bendedict Kim, Belize, http://discovermagazine.com/2014/dec/15-cave-of-the-crystal-maiden
 Nicholas Mott, “Why the Maya Fell: Climate Change, Conflict—And a Trip to the Beach?” National Geographic, November 11, 2012, https://news.nationalgeographic.com/news/2012/11/121109-maya-civilization-climate-change-belize-science/
 Ursula M. Cowgill, An Agricultural Study of the Southern Maya Lowlands (Connecticut: Yale University, 1962), 276-277
 Rossella Lorenzi, “Mayan Bones Reveal Painful End,” Seeker, November 14, 2012, https://www.seeker.com/mayan-bones-reveal-painful-end-1766045728.html
 Courtesy Granger, Mesoamericans succumb to deadly measles epidemic, https://www.nlm.nih.gov/nativevoices/timeline/184.html
 James L. Brewbaker, “Diseases of Maize in the Wet Lowland Tropics and the Collapse of the Classic Maya Civilization,” Economic Botany 33, No. 2 (June 1979): 101. https://www.jstor.org/stable/4254035
 Dave Scriven, Tree Ring. 2007. Australia, https://www.flickr.com/photos/furious-angel/961754056/
 Robin Wylie, “Severe drought’s explain the mysterious fall of the Maya,” BBC (February 2016): http://www.bbc.com/earth/story/20160222-severe-droughts-explain-the-mysterious-fall-of-the-maya
 Kevin Krajick, “Forest Razing by Ancient Maya Worsened Droughts, Says Study” Lamon- Doherty Earth Observatory (August 2012): https://www.ldeo.columbia.edu/news-events/forest-razing-ancient-maya-worsened-droughts-says-study
 Tiffany Stecker, “Tree Rings Reveal History of History-Changing Mexican Droughts,” Scientific American (February 2011): https://www.scientificamerican.com/article/tree-rings-reveal-mexican-drought-history/
Brewbaker, James L. “Diseases of Maize in the Wet Lowland Tropics and the Collapse of the Classic Maya Civilization,” Economic Botany 33, No. 2 (June 1979): 101. https://www.jstor.org/stable/4254035
Butler, Rhett A. Slash-and-burn agriculture in Belize (2008) Belize, https://news.mongabay.com/2012/03/airborne-lasers-discover-undocumented-deforestation-in-belize-park/
Cowgill, M Ursula, An Agricultural Study of the Southern Maya Lowlands. Connecticut: Yale University, 1962
Granger, Courtesy. Mesoamericans succumb to deadly measles epidemic, https://www.nlm.nih.gov/nativevoices/timeline/184.html
Kim, Bendedict. Belize, http://discovermagazine.com/2014/dec/15-cave-of-the-crystal-maiden
Krajick, Kevin. “Forest Razing by Ancient Maya Worsened Droughts, Says Study” Lamon- Doherty Earth Observatory (August 21, 2012): https://www.ldeo.columbia.edu/news-events/forest-razing-ancient-maya-worsened-droughts-says-study
Lorenzi, Rossella. “Mayan Bones Reveal Painful End,” Seeker (November 14, 2012): https://www.seeker.com/mayan-bones-reveal-painful-end-1766045728.html
“Mayans Disappearance – Why did the Mayans Collapse?” IP Factly (July 2015): http://ipfactly.com/why-did-the-mayans-collapse/
Mott, Nicholas. “Why the Maya Fell: Climate Change, Conflict—And a Trip to the Beach?” National Geographic. (November 11, 2012): https://news.nationalgeographic.com/news/2012/11/121109-maya-civilization-climate-change-belize-science/
Scriven, Dave. Tree Ring. 2007. Australia, https://www.flickr.com/photos/furious-angel/961754056/
Stecker, Tiffany. “Tree Rings Reveal History of History-Changing Mexican Droughts,” Scientific American (February 8, 2011): https://www.scientificamerican.com/article/tree-rings-reveal-mexican-drought-history/
Wylie, Robin. “Severe droughts explain the mysterious fall of the Maya,” BBC (February 22, 2016): http://www.bbc.com/earth/story/20160222-severe-droughts-explain-the-mysterious-fall-of-the-maya