“When you can’t irrigate your crops, you can’t have a city of 40,000, like some of the Maya cities were.”
If you want to see what is bound to happen to communities around the world as the climate changes, you can take a look at the Yucatan Peninsula. The ancient Mayan civilization that rose, flourished and then fell there owed its demise to environmental factors that could soon endanger modern-day communities.
Specifically, the changes to the area’s water table that precipitated the decline of the Mayans should serve as a warning to us, say scientists who have found that freshwater sources and the salinity even far inland can fluctuate wildly as a result of ocean tides.
They discovered this by placing sensors in bodies of water throughout the Yucatan Peninsula.
“Big parts of the Yucatan Peninsula sit on rock formations made of limestone, with fissures and caves throughout,” observes Aaron Coutino, one of the researchers who specializes in applied mathematics at the University of Waterloo in Canada.
“Rainwater and runoff accumulate in the cave formations and underground rivers, and that’s where much of the freshwater is on the Yucatan,” Coutino elucidates. “If you have changes in sea level or tidal activity, then what happens in those fissure zones is a mixing between the fresh water on the surface and the salty water that intrudes from the ocean underneath.”
Their fluctuating access to freshwater demonstrably impacted Mayan population and settlement patterns with recurring cycles of disruption until their entire civilization started to decline.
“Sometimes things in Maya cities were good, and sometimes people seem to disperse out into the countryside,” notes Marek Stastna, a professor of applied mathematics at the University of Waterloo who was a co-author of a study on inland tidal oscillations within the Yucatan Peninsula.
“There’s a variety of theories in the archeological community as to why. This research suggests it was to do with regular access to freshwater. The water stops being good for drinking and even stops being useful for irrigation. When you can’t irrigate your crops, you can’t have a city of 40,000, like some of the Maya cities were,” Stastna says.
Although the water table in the Yucatan is unique, other areas of the world are becoming increasingly vulnerable to changing climate patterns in their own ways, the scientists stress.
“Right now, you see how climate change expresses itself in places like British Columbia, with these huge forest fires. And in the Yucatan, climate change expresses itself through the underground water table. If you’re in Acadia, maybe the bigger concern is coastal erosion, but in the Yucatan change can manifest inland” Stastna explains.
“People shouldn’t be thinking about whether climate change is happening, but how it expresses itself in different places,” he says.